EMBRYOPSIDA Pirani & Prado (crown group)
Gametophyte dominant, independent, multicellular, thalloid, with single-celled apical meristem, showing gravitropism; cuticle +; cell walls with (1->4)-ß-D-glucans [xyloglucans], lignin +; rhizoids unicellular; several chloroplasts per cell; glycolate metabolism in leaf peroxisomes [glyoxysomes]; centrioles in vegetative cells 0, metaphase spindle anastral, predictive preprophase band of microtubules, phragmoplast + [cell wall deposition spreading from around the spindle fibres], plasmodesmata +; antheridia and archegonia jacketed, stalked; spermatogenous cells monoplastidic, centrioles develop de novo, associated with basal bodies of flagellae, multilayered structure +, proximal end of basal bodies lacking symmetry, stellate pattern associated with doublet tubules of transition zone; spermatozoids with a left-handed coil; male gametes with 2 lateral flagellae; oogamy; diploid embryo initially surrounded by haploid gametophytic tissue, plane of first division horizontal, suspensor/foot +, cell walls with nacreous thickenings; sporophyte multicellular, sporangium +, single, with polar transport of auxin, dehiscence longitudinal; meiosis sporic, monoplastidic, microtubule organizing centre associated with plastid, cytokinesis simultaneous, preceding nuclear division, sporocytes 4-lobed, with a quadripolar microtubule system; spores in tetrads, sporopollenin in the spore wall, wall with several trilamellar layers [white-line centred layers, i.e. walls multilaminate]; spores trilete [?level]; close association between the trnLUAA and trnFGAA genes on the chloroplast genome.
Note that many of the bolded characters in the characterization above are apomorphies in the streptophyte clade along the lineage leading to the embryophytes rather than being apomorphies of the embryophytes.
Abscisic acid, ?D-methionine +; sporangium with columella; stomata +, anomocytic, cell lineage that produces them with symmetric divisions [perigenous]; polar transport of auxins and class 1 KNOX genes expressed in the sporangium alone; MIKC, MI*K*C* and class 1 and 2 KNOX genes, post-transcriptional editing of chloroplast genes; gain of three group II mitochondrial introns.
[Hornworts + Polysporangiophyta]: archegonia embedded in the gametophyte; sporophyte long-lived, chlorophyllous, nutritionally largely independent of the gametophyte; sporophyte-gametophyte junction interdigitate, sporophyte cells showing rhizoid-like behaviour; spores trilete.
Sporophyte well developed, branched, free living, sporangia several; apical meristem +.
EXTANT TRACHEOPHYTA / VASCULAR PLANTS
Photosynthetic red light response, passive control of leaf hydration; (condensed or nonhydrolyzable tannins/proanthocyanidins +); vascular tissue +, sieve cells +, tracheids +, in both protoxylem and metaxylem; endodermis +; root xylem exarch [development centripetal]; stem with an apical cell; leaf blade with mean venation density 1.8 mm/mm2 [to 5 mm/mm2]; sporangia adaxial on the sporophyll, lacking columella, eusporangiate [sporangia derived from periclinal divisions of several epidermal cells, wall multilayered]; stellate pattern split between doublet and triplet regions of transition zone; placenta with single layer of transfer cells in both sporophytic and gametophytic generations, embryo with roots arising lateral to the main axis [plant homorhizic].[MONILOPHYTA + LIGNOPHYTA]
Branching ± monopodial; lateral roots +, endogenous, root cap +; tracheids with scalariform-bordered pits; leaves spirally arranged, with apical/marginal growth, venation development basipetal, growth determinate; sporangia borne in pairs and grouped in terminal trusses, dehiscence longitudinal, a single slit; cells polyplastidic, microtubule organizing centres not associated with plastids, diffuse, perinuclear; male gametes multiflagellate, basal bodies staggered, blepharoplasts paired; chloroplast long single copy ca 30kb inversion [from psbM to ycf2].
Plant woody; lateral root origin from the pericycle, root apex multicellular; endodermis +; shoot apical meristem multicellular; lateral meristems +, cork cambium +, [producing cork abaxially], vascular cambium bifacial [producing phloem abaxially and xylem adaxially].
EXTANT SEED PLANTS/SPERMATOPHYTA
Plant evergreen; nicotinic acid metabolised to trigonelline, (cyanogenesis via tyrosine pathway); primary cell walls rich in xyloglucans and/or glucomannans, 25-30% pectin [Type I walls]; lignins derived from (some) sinapyl and particularly coniferyl alcohols [hence with p-hydroxyphenyl and guaiacyl lignin units, so no Maüle reaction]; root with xylem and phloem originating on alternate radii, vascular tissue not medullated, cork cambium deep seated; arbuscular mycorrhizae +; shoot apical meristem interface specific plasmodesmatal network; stem with vascular cylinder around central pith [eustele], phloem abaxial [ectophloic], endodermis 0, xylem endarch [development centrifugal]; wood homoxylous, tracheids and rays alone, tracheid/tracheid pits circular, bordered; mature sieve tube/cell lacking functioning nucleus, sieve tube plastids with starch grains; phloem fibres +; stem cork cambium superficial; branches exogenous; leaves with single trace from vascular sympodium [nodes 1:1]; stomatal pore with active opening in response to leaf hydration, control by abscisic acid, metabolic regulation of water use efficiency, etc.; leaves with petiole and lamina, spiral, development basipetal, blade simple; axillary buds +, not associated with all leaves; prophylls two, lateral; plant heterosporous, sporangia borne on sporophylls; microsporophylls aggregated in indeterminate cones/strobili; true pollen +, grains mono[ana]sulcate, exine and intine homogeneous; ovules unitegmic, parietal tissue 2+ cells across, megaspore tetrad linear, functional megaspore single, chalazal, lacking sporopollenin, megasporangium indehiscent; male gametophyte development first endo- then exosporic, tube developing from distal end of grain, gametes two, developing after pollination, with cell walls; female gametophyte endosporic, initially syncytial, walls then surrounding individual nuclei; seeds "large" [ca 8 mm3], but not much bigger than ovule, with morphological dormancy; embryo cellular ab initio, endoscopic, plane of first cleavage of zygote transverse, suspensor +, short-minute, embryo axis straight, so shoot and root at opposite ends [plant allorhizic], white, cotyledons 2; plastid transmission maternal; ycf2 gene in inverted repeat, whole nuclear genome duplication [zeta duplication], two copies of LEAFY gene, PHY gene duplications [three - [BP [A/N + C/O]] - copies], nrDNA with 5.8S and 5S rDNA in separate clusters; mitochondrial nad1 intron 2 and coxIIi3 intron and trans-spliced introns present.
Lignans, O-methyl flavonols, dihydroflavonols, triterpenoid oleanane, apigenin and/or luteolin scattered, [cyanogenesis in ANITA grade?], S [syringyl] lignin units common [positive Maüle reaction - syringyl:guaiacyl ratio more than 2-2.5:1], and hemicelluloses as xyloglucans; root apical meristem intermediate-open; root vascular tissue oligarch [di- to pentarch], lateral roots arise opposite or immediately to the side of [when diarch] xylem poles; origin of epidermis with no clear pattern [probably from inner layer of root cap], trichoblasts [differentiated root hair-forming cells] 0, exodermis +; shoot apex with tunica-corpus construction, tunica 2-layered; reaction wood ?, associated gelatinous fibres [g-fibres] with innermost layer of secondary cell wall rich in cellulose and poor in lignin; starch grains simple; primary cell wall mostly with pectic polysaccharides, poor in mannans; tracheid:tracheid [end wall] plates with scalariform pitting, wood parenchyma +; sieve tubes enucleate, sieve plate with pores (0.1-)0.5-10< µm across, cytoplasm with P-proteins, cytoplasm not occluding pores of sieve plate, companion cell and sieve tube from same mother cell; sugar transport in phloem passive; nodes 1:?; stomata brachyparacytic [ends of subsidiary cells level with ends of pore], outer stomatal ledges producing vestibule, reduction in stomatal conductance to increasing CO2 concentration; lamina formed from the primordial leaf apex, margins toothed, development of venation acropetal, secondary veins pinnate, overall growth ± diffuse, venation hierarchical-reticulate, veins (1.7-)4.1(-5.7) mm/mm2, endings free; most/all leaves with axillary buds; flowers perfect, pedicellate, ± haplomorphic, parts spiral [esp. the A], free, numbers unstable, development in general centripetal; P +, members each with a single trace, outer members not sharply differentiated from the others, not enclosing the floral bud; A many, filament not sharply distinguished from anther, stout, broad, with a single trace, anther introrse, tetrasporangiate, sporangia in two groups of two [dithecal], ± embedded in the filament, with at least outer secondary parietal cells dividing, each theca dehiscing longitudinally, endothecium +, endothecial cells elongated at right angles to long axis of anther; tapetum glandular, cells binucleate; microspore mother cells in a block, microsporogenesis successive, walls developing by centripetal furrowing; pollen subspherical, tectum continuous or microperforate, ektexine columellate, endexine thin, compact, lamellate only in the apertural regions; nectary 0; carpels present, superior, free, several, ascidiate, with postgenital occlusion by secretion, stylulus short, hollow, cavity not lined by distinct epidermal layer, stigma ± decurrent, carinal, dry [not secretory]; ovules few [?1]/carpel, marginal, anatropous, bitegmic, micropyle endostomal, outer integument 2-3 cells across, often largely subdermal in origin, inner integument 2-3 cells across, often dermal in origin, parietal tissue 1-3 cells across [crassinucellate], nucellar cap?; megasporocyte single, hypodermal, functional megaspore lacking cuticle; female gametophyte four-celled [one module, nucleus of egg cell sister to one of the polar nuclei]; supra-stylar extra-gynoecial compitum +; ovule not increasing in size between pollination and fertilization; pollen binucleate at dispersal, mature male gametophyte trinucleate, germinating in less than 3 hours, pollination siphonogamous, tube elongated, growing between cells, growth rate 20-20,000 µm/hour, outer wall pectic, inner wall callose, with callose plugs, penetration of ovules via micropyle [porogamous], whole process takes ca 18 hours, distance to first ovule 1.1-2.1 mm; male gametes lacking cell walls, flagellae 0, double fertilization +, ovules aborting unless fertilized; P deciduous in fruit; seed exotestal, becoming much larger than ovule at time of fertilization; endosperm diploid, cellular [micropylar and chalazal domains develop differently, first division oblique, micropylar end initially with a single large cell, divisions uniseriate, chalazal cell smaller, divisions in several planes], copious, oily and/or proteinaceous; embryogenesis cellular; dark reversal Pfr -> Pr; Arabidopsis-type telomeres [(TTTAGGG)n]; 2C genome size 1-8.2 pg [1 pg = 109 base pairs], whole nuclear genome duplication [epsilon duplication], ndhB gene 21 codons enlarged at the 5' end, single copy of LEAFY and RPB2 gene, knox genes extensively duplicated [A1-A4], AP1/FUL gene, paleo AP3 and PI genes [paralogous B-class genes] +, with "DEAER" motif, SEP3/LOFSEP and three copies of the PHY gene, [PHYB [PHYA + PHYC]].
[NYMPHAEALES [AUSTROBAILEYALES [[CHLORANTHALES + MAGNOLIIDS] [MONOCOTS [CERATOPHYLLALES + EUDICOTS]]]]]: wood fibres +; axial parenchyma diffuse or diffuse-in-aggregates; pollen monosulcate [anasulcate], tectum reticulate-perforate [here?]; ?genome duplication; "DEAER" motif in AP3 and PI genes lost, gaps in these genes.
[AUSTROBAILEYALES [[CHLORANTHALES + MAGNOLIIDS] [MONOCOTS [CERATOPHYLLALES + EUDICOTS]]]]: vessel elements with scalariform perforation plates in primary xylem; essential oils in specialized cells [lamina and P ± pellucid-punctate]; tension wood +; tectum reticulate; anther wall with outer secondary parietal cell layer dividing; carpels plicate; nucellar cap + [character lost where in eudicots?]; 12BP [4 amino acids] deletion in P1 gene.
[[CHLORANTHALES + MAGNOLIIDS] [MONOCOTS [CERATOPHYLLALES + EUDICOTS]]] / MESANGIOSPERMAE: benzylisoquinoline alkaloids +; sesquiterpene synthase subfamily a [TPS-a] [?level], polyacetate derived anthraquinones + [?level]; outer epidermal walls of root elongation zone with cellulose fibrils oriented transverse to root axis; P more or less whorled, 3-merous [possible position]; pollen tube growth intra-gynoecial; embryo sac bipolar, 8 nucleate, antipodal cells persisting; endosperm triploid.
[MONOCOTS [CERATOPHYLLALES + EUDICOTS]]: (extra-floral nectaries +); (veins in lamina often 7-17 mm/mm2 or more [mean for eudicots 8.0]); (stamens opposite [two whorls of] P); (pollen tube growth fast).
[CERATOPHYLLALES + EUDICOTS]: ethereal oils 0.
EUDICOTS: (Myricetin, delphinidin +), asarone 0 [unknown in some groups, + in some asterids]; root epidermis derived from root cap [?Buxaceae, etc.]; (vessels with simple perforation plates in primary xylem); nodes 3:3; stomata anomocytic; flowers (dimerous), cyclic; K/outer P members with three traces, ("C" +, with a single trace); A few, (polyandry widespread, initial primordia 5, 10, or ring, ± centrifugal), filaments fairly slender, anthers basifixed; microsporogenesis simultaneous, pollen tricolpate, apertures in pairs at six points of the young tetrad [Fischer's rule], cleavage centripetal, wall with endexine; G with complete postgenital fusion, stylulus/style solid [?here]; seed coat?
[PROTEALES [TROCHODENDRALES [BUXALES + CORE EUDICOTS]]]: plant woody; (axial/receptacular nectary +).
[TROCHODENDRALES [BUXALES + CORE EUDICOTS]]: benzylisoquinoline alkaloids 0; euAP3 + TM6 genes [duplication of paleoAP3 gene: B class], mitochondrial rps2 gene lost.
[BUXALES + CORE EUDICOTS]: ?
CORE EUDICOTS / GUNNERIDAE: (ellagic and gallic acids +); leaf margins serrate; compitum + [one place]; micropyle?; whole nuclear genome duplication [palaeohexaploidy, gamma triplication], PI-dB motif +, small deletion in the 18S ribosomal DNA common.
[ROSIDS ET AL. + ASTERIDS ET AL.] / PENTAPETALAE: root apical meristem closed; (cyanogenesis also via [iso]leucine, valine and phenylalanine pathways); flowers rather stereotyped: 5-merous, parts whorled; P = calyx + corolla, the calyx enclosing the flower in bud, sepals with three or more traces, petals with a single trace; stamens = 2x K/C, in two whorls developing internally/adaxially to the corolla whorl and successively alternating, (numerous, but then usually fasciculate and/or centrifugal); pollen tricolporate; G , G  also common, when [G 2], carpels superposed, compitum +, placentation axile, style +, stigma not decurrent; endosperm nuclear; fruit dry, dehiscent, loculicidal [when a capsule]; RNase-based gametophytic incompatibility system present; floral nectaries with CRABSCLAW expression.
[SANTALALES [BERBERIDOPSIDALES [CARYOPHYLLALES + ASTERIDS]]] / ASTERIDS ET AL. / SUPERASTERIDS : ?
[BERBERIDOPSIDALES [CARYOPHYLLALES + ASTERIDS]]: ?
[CARYOPHYLLALES + ASTERIDS]: seed exotestal; embryo long.
ASTERIDS / Sympetalae redux? / ASTERIDAE / ASTERANAE Takhtajan: nicotinic acid metabolised to its arabinosides; (iridoids +); tension wood decidedly uncommon; C enclosing A and G in bud, (connate, if evident only early in development and then petals often appearing to be free); anthers dorsifixed?; (nectary gynoecial); style +, long; ovules unitegmic, integument thick, endothelium +, nucellar epidermis does not persist; exotestal cells lignified, esp. on anticlinal and/or inner periclinal walls; endosperm cellular.
[ERICALES [ASTERID I + ASTERID II]]: (ovules lacking parietal tissue) [tenuinucellate].
[ASTERID I + ASTERID II] / CORE ASTERIDS: ellagic acid 0, non-hydrolysable tannins not common; sugar transport in phloem active; inflorescence basically cymose; A = and opposite sepals or P, (numerous, usu. associated with increased numbers of C or G); (pollen with orbicules); style short[?]; duplication of the PI gene.
ASTERID I / LAMIIDAE: G , superposed; loss of introns 18-23 in d copy of RPB2 gene.
[GARRYALES [GENTIANALES [[VAHLIACEAE + SOLANALES] [BORAGINALES + LAMIALES]]]]: loss of introns 18-23 in RPB2 d copy.
[GENTIANALES [[VAHLIACEAE + SOLANALES] [BORAGINALES + LAMIALES]]]: (8-ring deoxyflavonols +); vessel elements with simple perforation plates; nodes 1:1; C forming a distinct tube, initiation late [sampling!]; A epipetalous; (vascularized) nectary at base of G; style long; several ovules/carpel; fruit a septicidal capsule, K persistent.
[[VAHLIACEAE + SOLANALES] [BORAGINALES + LAMIALES]]: endothelium +; chalazal endosperm haustorium +.
[VAHLIACEAE + SOLANALES]: ?
Phylogeny. For the relationships of Vahliaceae, previously of very uncertain position, see Refulio-Rodriguez and Olmstead (2014) and discussion under Gentianales; they were placed sister to Solanales, although support was strong only in Bayesian analyses, and so they are provisionally placed here.
VAHLIACEAE Dandy Main Tree
Herbs or subshrubs; iridoids +; petiole bundle arcuate; hairs uniseriate-glandular; leaves opposite; flowers small; K valvate, C free; A not adnate to C; tapetal cells plurinucleate; ovary inferior, [2(-3)], nectary +, 1-locular, placentae apical, pendulous, ± confluent, styles distinct, diverging, stigmas ± capitate; ovules many/carpel, bitegmic, micropyle endostomal, outer integument 2-4 cells across, inner integument 2-4 cells across, parietal tissue 0, fruit a septicidal capsule, K persistent; exotestal cells ± elongated, outer or all walls thickened, endotestal cells with well-developed U-thickenings, neither lignified, raphe disappears; endosperm slight; n = 6, 9.
1[list]/8. Africa and Madagascar to India (map: from Bridson 1974; Trop. Afr. Fl. Pl. Ecol. Distr. 1. 2003).
Evolution. Divergence & Distribution. Friis and Skarby (1982) described two species of Scandianthus from the Upper Cretaceous of Sweden which they tentatively associated with Vahlia (see also the morphological analysis in Martínez-Millán 2010); they all have an unilocular gynoecium with apical-lateral placentae and free styles and fruits with septicidal dehiscence. Friis and Skarby (1982) also noted a phenetic similarity to some Hydrangeaceae, Phyllonomaceae, Escalloniaceae, and even some Saxifragaceae s. str.. However, Scandianthus has ten stamens, a decidedly unusual number for any member of the [asterid I + asterid II] clade, and so it may well be better placed somewhere around Cornales.
Chemistry, Morphology, etc. Although the ovary has only a single locule, dehiscence of the fruit occurs between the styles, and this is equivalent to dehiscence along the septal radii.
Some information is taken from Thouvenin (1890), Mauritzon (1933: ovules), Raghavan and Srinivasan (1942) and Saxena (1973: both floral morphology and embryology, no parietal tissue), and Cutler and Gregory (1998: anatomy).
Classification. Bridson (1974) monographed the family.
Previous relationships. Vahliaceae were included in Saxifragales by Cronquist (1981) and Takhtajan (1997).
Synonymy: Vahliales Doweld
SOLANALES Berchtold & J. Presl Main Tree
O-methyl flavonols (flavones) +, iridoids, myricetin 0; inflorescence terminal; K connate; anther sacs with placentoids; pollen tube usu. with callose; K persistent in fruit; endosperm development? - 5 families, 165 genera, 4080 species.
Age. Crown-group Solanales may date from (82-)78, 76(-72) m.y. (Wikström et al. 2001); Bremer et al. (2004) date them to ca 100 m.y. and Lemaire et al. (2011b) to (93-)71(-50) m.y., Magallón and Castillo (2009) suggest ages of ca 73 m.y. and Bell et al. (2010) ages of (85-)76, 71(-62) m.y..
Note: Possible apomorphies are in bold. However, the actual level at which many of these features, particularly the more cryptic ones, should be assigned is unclear. This is partly because many characters show considerable homoplasy, in addition, basic information for all too many is very incomplete, frequently coming from taxa well embedded in the clade of interest and so making the position of any putative apomorphy uncertain. Then there is the not-so-trivial issue of how ancestral states are reconstructed...
Evolution. Divergence & Distribution. Endress (2011a) suggested that a key innovation for a clade [Lamiales + Solanales] might be anthers with a pollen sac placentoid - unfortunately, the two appear not to be sister taxa.
Phylogeny. For the relationships of Solanales, see Refulio-Rodriguez and Olmstead (2014), and discussion under Gentianales.
Within Solanales, Montiniaceae were found to be sister to [Solanaceae + Convolvulaceae] (B. Bremer 1996, see also Soltis & Soltis 1997). D. Soltis et al. (2000) found strong support for the association of Montinia and Hydrolea; Sphenoclea was not included. With the inclusion of the latter and broader sampling (three genera) in Montiniaceae, B. Bremer et al. (2002) found strong support for the association of Sphenoclea and Hydrolea, but only just above 50% for the association of Montiniaceae with that pair; support was stronger in Soltis et al. (2011; see also Refulio-Rodriguez & Olmstead 2014). The topology of the tree here follows that of these latter papers.
Includes Convolvulaceae, Hydroleaceae, Montiniaceae, Solanaceae, Sphenocleaceae.
Synonymy: Cestrales Martius, Convolvulales Berchtold & J. Presl, Cuscutales Martius, Hydroleales Martius, Nolanales Lindley, Sphenocleales Doweld
[Montiniaceae [Sphenocleaceae + Hydroleaceae]]: route I secoiridoids +; petiole bundle(s) arcuate; stigma ± capitate.
Age. The age for this node is estimated to be (71-)66, 65(-60) m.y. (Wikström et al. 2001), (79-)65, 61(-47) m.y. (Bell et al. 2010) or ca 92 m.y. (Bremer et al. (2004).
Evolution. Divergence & Distribution. The character "pits vestured" may be best placed at this node.
MONTINIACEAE Nakai Back to Solanales
Shrubs, trees (lianes); plants with a peppery smell; plant slightly tanniniferous; cambium storied or not; pits vestured; young stem with a vascular cylinder (separate bundles); (medullary bundles +); pericyclic fibres 0; crystal sand, acicular crystals and styloids usu. all +; petiole arc of (rounded) bundles (+ additional strands); axillary tuft of hairs at nodes; (stomata anisocytic - some Grevea); leaves also opposite; bracteoles 0; flowers imperfect, small; K small, C free [absolutely so - Montinia], (valvate); nectary vascularized; staminate flowers: 3-4(-5)-merous; A not adnate to C, anthers extrorse, ± basifixed; pollen grains large; pistillode minute; carpellate flowers: 4-merous; staminodes + (0); ovary inferior, placentation intrusive parietal-subaxile, style short, stout, hollow, stigma with 2 large lobes (style branched, stigma commissural, not capitate - Kaliphora); ovules 1-12/carpel, (campylotropous, apotropous - Kaliphora), integument ca 7 cells across, parietal tissue ca 1 cell across, nucellus base thin [Montinia], fruit a capsule; seeds winged, exotesta lignified, periclinal walls thickened, (adjacent wall of mesotesta also thickened [Montinia)]; or fruit indehiscent, placentae at least initially fleshy; or fruit a 2-seeded drupe [Kaliphora]; testa thin-walled, ± pulpy when wetted [Grevea]; or fruit a drupe; (exotesta not persistent - Grevea); endosperm +/0, ?development, hemicellulosic, walls thick, layered, cotyledons accumbent, foliaceous, radicle oblique; cotyledonary petioles connate [Montinia]; n = 16 [Kaliphora], 34 [Montinia].
3[list]/5. Africa and Madagascar (map: from Milne-Redhead & Metcalfe 1955; Verdcourt 1975; Bosser 1990; Brummit 2007 [C. and W. Africa]). [Photos - Kaliphora, Montinia Fruits © Serban Procheŝ.]
Age. The age for crown-group Montiniaceae is around 42 m.y. (Bremer et al. (2004).
Chemistry, Morphology, etc. Pericyclic fibres may be poorly developed - see Kaliphora, ?others; Grevea has vascular bundles in the pith. The axillary tufts of hairs are least well developed in Kaliphora. Kaliphora is anisophyllous, and the leaves are only subopposite; subsequent leaves may be borne on the same side of the stem. The pollen (Hideux & Ferguson 1976) is rather like that of some Araliaceae.
See Milne-Redhead and Metcalfe (1955) for general morphology and anatomy, Mauritzon (1933: Corokia) for embryology, Hegnauer (1973, 1990, as Saxifragaceae) for chemistry, Dahlgren et al. (1977) for germination and iridoids, Ramamonjiarisoa (1980), Carlquist (1989), and Wangerin (1906), Gregory (1998) for vegetative anatomy, Krach (1976, 1977) and Takhtajan and Trifonova (1999) for testa anatomy, and Ronse Decraene (1992) and Ronse Decraene et al. (2000a) for details of floral morphology.
Previous Relationships. Montiniaceae have been hard to place, and have generally been included somewhere around Saxifragaceae. Thus Cronquist (1981) included them in his heterogeneous Grossulariaceae, while Takhtajan (1997) placed them as a separate family (Kaliphoraceae were adjacent) in his Hydrangeales, ex Saxifragaceae.
Synonymy: Kaliphoraceae Takhtajan
[Sphenocleaceae + Hydroleaceae]: placentae swollen [?level]; ovules many/carpel; endosperm cellular, at most scanty, with multicellular micropylar haustoria.
SPHENOCLEACEAE Baskerville Back to Solanales
Herbs, rather fleshy, annual; fructose with isokestose linkages, cyclic thiosulphinates [zeylanoxides] +; cork ?mid-cortical; cortical air spaces +; stomata tetracytic; inflorescences spicate; C quincuncial, free, tube formation early, lateral veins connate and commissural; A not adnate to C; pollen trinucleate; nectary 0; G ± inferior, placenta massive, style short, stigma subcapitate, wet; integument "massive", hypostase 0; synergids elongated, antipodal cells degenerate; fruit capsular, capsule circumscissile; exotestal cells polygonal, inner walls thickened and with radial spine-like processes; endosperm slight, walls thick; n = 12, 16, 20, etc.
1/2. Pantropical (map: from Brummit 2007; Australia's Virtual Herbarium v.2013). [Photo - Habit © B. Hammel]
Evolution. Ecology & Physiology. The cyclic thioslphinates, and perhaps also the secoiridoids, seem to be responsible for the potent allelopathic efect of Spencolea zeylanica, both on rice and othe plants (Hirai et al. 2000 and references.
Chemistry, Morphology, etc. Corolla tube formation is of the early type, and the corolla lobes are characteristically incurved; the lateral veins of adjacent lobes are fused producing commissural veins. The anticlinal walls of the testa are shown as being massively thickened in Takhtajan (2010).
Some information is taken from Kausik and Subramanyam (1946: embryology), Subramanyam (1950b: general), Monod (1980), Erbar (1995c: floral morphology), and Tobe and Morin (1996: embryology).
Previous Relationships. Sphenocleaceae, along with Hydrolea, another genus of uncertain position, were placed near Boraginaceae by Cosner et al. (1994). However, in morphological studies (e.g. Gustafsson & Bremer 1995) Sphenocleaceae seem to be satisfactorily positioned well within Asterales. Indeed, Sphenocleaceae have often been associated with Campanulaceae (e.g. they are placed in Campanulales by Takhtajan 1997), although they lack latex.
HYDROLEACEAE Edwards Back to Solanales
Herb to shrubby; mycorrhizae 0; chemistry?; axillary-sublateral thorns or not; cork?; vessel elements?; pits vestured; stomata?; lamina margin toothed to entire; flowers 4-5-merous; K basally connate, C tube formation late, connate; A versatile, filament base abruptly broadened/lobed; nectary 0/+; G diagonal, [2(-4)], placentae bilobed, styles separate, ± spreading, stigma slightly funneliform or capitate; ovules mostly pleurotropous, funicular bundle absent, integument 6-8 cells across; antipodals degenerating early; fruit a septi-(+ loculi)cidal capsule, (irregularly dehiscent); seeds longitudinally ridged and ruminate, exotestal cells thin-walled, endotestal cells tanniniferous, with a cuticle; n = (9) 10 (12).
1/12. Tropical, warm temperate (map: from Davenport 1988; FloraBase 2007). [Photo - Hydrolea Flower © B. Kenney]
Chemistry, Morphology, etc. Hydrolea appears to lack mycorrhizae.
The axillary inflorescences may be cymose. Davenport (1988) suggested that a nectary disc is absent. The two carpels are shown as being oblique by Schnizlein (1843-1870: fam. 147), and this is confirmed by Erbar et al. (2005), even for Hydrolea palustris, which has flowers with the median sepal abaxial. Di Fulvio (1997) notes that the four ventral bundles of the two carpels are all connate in the center of the ovary - c.f. Hydrophyllaceae/Nameae where there are often two or four such bundles, rarely a single bundle (di Fulvio 1997). There are no nuclear inclusions (di Fulvio 1991).
Details of embryology are taken from Svensson (1925) and di Fulvio (1989b, 1990); for pollen, see Constance and Chuang (1982).
Classification. Davenport (1988) monographed the genus.
Previous Relationships. Hydrolea has usually been included in Hydrophyllaceae (e.g. Cronquist 1981; Takhtajan 1997). Not only molecular differences but also axile versus parietal placentation and embryological differences (see di Fulvio de Basso 1990) separate the two.
Synonymy: Sagoneaceae Martynov
[Convolvulaceae + Solanaceae]: coumarins, caffeic acid esters, tropane [polyhydroxynortropanes], pyrrolidine, etc., alkaloids, flavonol and flavone glycosides, acylated anthocyanins +, tannins, iridoids 0; internal phloem +; leaves with conduplicate vernation; flowers with oblique symmetry; C-tube formation late, C contorted-plicate or induplicate-valvate; tapetal cells multinucleate; G opposite petals; ovules many/carpel, integument (5-)9-20(-40) cells across, (endothelium ?0); K persistent in fruit; testa often multiplicative; young seeds starchy, endosperm haustoria 0, cotyledons incumbent.
Age. The two families may have diverged (71-)66, 65(-61) m.y. (Wikström et al. 2001), (91-)86(-81) m.y. (Bremer et al. 2004), (69.7-)62.1(-54.4) (Paape et al. 2008), (57.2-)52(-46.8) m.y. (Magallón et al. 1999), (74-)62, 59(-49) m.y. (Bell et al. 2010) m.y.a., (54-)49(-46) m.y.a. (Särkinen et al. 2013), or a mere ca 37.5 m.y.a. (Xue et al. 2012). However, an age of over 150 m.y. is suggested by Eserman et al. (2013), and although the error bars are huge, they do not overlap with the other dates mentioned (except those suggested by Bremer et al.).
Evolution. Divergence & Distribution. Flowers with oblique symmetry may be an apomorphy at this level, or even higher.
Plant-Animal Interactions. Chrysomelidae-Cassidinae+Hispinae and -Criocerinae beetle larvae like members of this clade, especially Convolvulaceae (Schmitt 1988; Jolivet 1988; Buzzi 1994; Vencl & Morton 1999).
Chemistry, Morphology, etc. Pyrrolizidine, tropane and pyrrolidine alkaloids are all synthesised from an ornithine precursor (Hegnauer 1973; Dahlgren 1988). Gemeinholzer and Wink (2001) discuss the sporadic distribution of tropane alkaloids in Solanaceae; they are known from Schizanthus and other clades; see Schimming et al. (1998) for the distribution of polyhydroxynortropanes (in most Convolvulaceae, not in Cuscuteae, unknown in Humbertia, scattered in Solanaceae. Eich (2008) provides an extensive summary of the distribution of secondary metabolites in these two families placed in the context of phylogeny and Kaltenegger et al. (2013) discuss the evolution of pyrrolizinie alkaloids in particular, which, even where they occur in Convolvulaceae, are sporadically distributed.
The corolla lobes have a thicker central area that is distinct from the margins because of the contorted-plicate or induplicate-valvate aestivation of the corolla; c.f. the "winged" corolla scattered in Asterales. Corner (1976) did not mention an endothelium for Convolvulaceae, but c.f. Kaur (1969) and Kaur and Singh (1970).
CONVOLVULACEAE Jussieu, nom. cons. Back to Solanales
Plant laticiferous; stomata usu. paracytic; lamina margins entire; K quincuncial, large, free; anther placentoid 0; pollen tectum imperforate; stigma dry; ovules apotropous; rpl2 intron deleted.
57[List]/1625 - six groups below. World wide (map: from Meusel et al. 1978; Staples & Brummit 2007).
Age. Crown-group diversification may have begun around 68 m.y.a. (Dillon et al. 2009).
1. Humbertioideae Roberty
Large tree; chemistry?; vascular bundles collateral; petiole bundle annular; latex cells in the flowers alone; flowers single, axillary, strongly obliquely monosymmetric; A adnate to base of C, filaments bent in bud; ?pollen; style clavate; ?ovule morphology; fruit a few-seeded drupe; ?seed coat; endosperm copious; seedling?; n = ?.
1/1: Humbertia madagascariensis. Madagascar.
Synonymy: Humbertiaceae Pichon, nom. cons.
[Eryciboideae, Cardiochlamyeae [Convolvuloideae, Cuscutoideae, Dichondroideae]]
Plant climbing by twining [right-twining]; secondary thickening anomalous; latex canals +, usu. articulated; ovules (1-)2(-4)/carpel, erect; cotyledons often complexly folded or coiled.
2. Eryciboideae (Endlicher) Roberty
Liane; inflorescence ?racemose, branched (± fasciculate); corolla lobes with thin margins forming two lobes; pollen 3-colpate, smooth; ovary 1-locular, style 0, stigma conical-radiate; fruit a berry, 1-seeded; mesotestal cells little elongated and thickened; seedling?; n = ?
1/70. Southeast Asia, Indo-Malesia to Australia (Map: from Hoogland 1953a; Flora China 16. 20; Australia's Virtual Herbarium xii.2012).
Synonymy: Erycibaceae Meisner
3. Cardiochlamyeae Stefanovic & Austin
Plant liane (vine); hairs T-shaped; leaf base cordate; inflorescence racemose; bracts foliaceous, sessile; pollen 3-colpate (pantoporate - Cardiochlamys; style single, stigma capitate (slightly two-lobed); fruit indehiscent, 1-seeded [= utricle], K accrescent, forming a wing; seedling with ovate cotyledon; n = ?
5/24. Madagascar, Southeast Asia, West Malesia (Map: from Staples 2006).
[Convolvuloideae, Cuscutoideae, Dichondroideae]: Plants herbaceous, vines (lianes to 30 m), (shrubs); (cork pericyclic); (fibers or sclereids +); unicellular T-shaped hairs common (hairs stellate); leaves conduplicate, (compound; margins lobed; toothed [dentate - Hyalocystis]); inflorescence cymose; pollen pantoporate or 3-polycolpate; G [2(-5)], stigmas capitate, with multicellular papillae or punctate and smooth; integument vascularized, with unbranched bundle, 5-10 cells across, parietal tissue 1-3 cells across, placental obturator common; fruit usu. a variously dehiscent capsule; testa anatomy complex, exotesta with papillae or hairs, usu. little thickened, outer hypodermis of small cells, little thickened, inner hypodermis elongated or not, of 1+ palisade layers, thickened, 2-8 layers of sclereidal cells underneath; endosperm nuclear, storing galactomannans [?always], embryo green, curved, cotyledons bifid/bilobed, suspensor haustorium +; n = 7-15+; chloroplast gene atpB with 6-15 bp deletion, ycf15 absent, trnF with 150 bp deletion; incompatibility system sporophytic.
49/1375. World-wide (map: from Meusel et al. 1978; Lebrun 1977; Staples & Brummit 2007). [Photo - Flower, Fruit.]
4. Convolvuloideae Burnett [Aniseae Convolvuleae Merremieae Ipomoeae]
Homospermidine synthase +, (pyrrolizine alkaloids +), (ergoline alkaloids + - Convolvuleae); (plant prostrate, mat-forming), (woody); lamina with secondary veins palmate, base cordate; inflorescence a dichasial cyme; C with interplical veins; (G with false septum - Mina); embryo sac much elongated [Ipomoea].
Ipomoea (500 - I. batatas, the sweet potato), Convolvulus (100), Argyreia (90).
Age. The divergence of Merremieae and Ipomoeeae has been dated to (70-)55.3(-47.8) m.y. (Eserman et al. 2013), rather old; the clade age in Dillon et al. (2009) that is compared with this age is the crown-group age of the whole family, not just a subclade of it, and that in Wikström et al. (2001) is the age of stem-group Convolvulaceae.
Synonymy: Evolvulaceae Berchtold & J. Presl, Poranaceae J. Agardh
5. Dichondroideae Roberty [Dichondreae Cresseae Maripeae Jacquemontieae]
Lamina base cuneate (cordate); cyme monochasial (dichasial), (inflorescence racemose - Calycobolus); styles deeply divided, (unequal), (gynobasic), (single), (mesotestal cells little elongated and thickened - Maripeae); reversion to a non-edited start codon for the psbL gene.
Jacquemontia (90), Merremia (70).
Synonymy: Cressaceae Rafinesque, Dichondraceae Dumortier, nom. cons.
6. Cuscutoideae Link
Plant parasitic; internal phloem 0; leaves reduced to scales; inflorescence details?; corolla imbricate, infrastaminal scales + ["corona"], fimbriate; anther wall 3 cells across; tapetal cells binucleate, (amoeboid); pollen (bi-)trinucleate, (surface reticulate); styles separate to connate, stigma capitate to elongated; ovules with integument (?8-)15-17 cells across, usu. unvascularized, parietal tissue absent, endothelium 0; megaspore mother cells several, competition between the developing embryo sacs, embryo sac bisporic, spores chalazal, eight-celled [Allium type] (normal); testa multiplicative; embryo spirally coiled, (almost) acotyledonous; root absent.
1/145. More or less the range of the family.
Synonymy: Cuscutaceae Dumortier, nom. cons.
Evolution. Divergence & Distribution. As Stefanovic et al. (2003) note, characters for their /Dicranostyloideae (= Dichondroideae) will depend very much on the position of Jacquemontia, currently unresolved in that clade. Eserman et al. (2013) discuss the evolution of a number of characters in Ipomoeeae.
Ecology & Physiology. The Convolvuloideae clade has about the second highest number of scandent species in the New World (Apocynaceae are number 1, Fabaceae are ± = number 2 - Gentry 1991).
Cuscuta (dodder) is a morphologically quite distinctive (see below) parasite, although species may have some chlorophyll. For a model of nutrient flow between host and parasite, see Hibberd and Jaeschke (2001). The haustoria by which dodder is attached to its host are often described as being modified roots, although elements of their development are quite different from that of roots (Alakonya et al. 2012).
Pollination Biology & Seed Dispersal. The flowers often last for only a single day. Smith et al. (2010) noted that white corollas were relatively uncommon in Ipomoea subg. Quamoclit because clades in which they evolved speciated relatively less than the others, while McDonald et al. (2011) discuss the numerous origins of self- from cross pollination (and reversals) in Ipomoea.
Convolvulaceae is the only asterid family that has seeds showing physical dormancy. This is caused by the thick, hard seed coat found in most members of the family, water initially penetrating the seed only at particular places in the coat (Jayasuriya et al. 2009); indeed, such thick and complex seed coats are unique in the asterid I + II clade.
Bacterial/Fungal Associations. The ergoline alkaloids of Convolvulaceae like Ipomoea and Turbina appear to be synthesized by associated ascomycete clavicipitalean fungi and are found in tissues where those fungi also occur (e.g. Ahimsa-Müller et al. 2007; Markert et al. 2008; see also Eserman et al. 2013). About 20% of Ipomoeeae form associations with Periglandula and are ergot alkaloid-positive (Beaulieu et al. 2012). However, pyrrolizidine alkaloids are synthesized by the plant, and homospermidine synthase (HSS) is the first gene in the PA biosynthetic pathway; PA alkaloids may have evolved more than once in the family, but HSS evolved only once (the apomorphy!) in the [Aniseae + Merremieae + Ipomoeae + Convolvuleae] clade (see Stefanovic et al. 2003) following a gene duplication (Reimann et al. 2004; Kaltenegger et al. 2013).
Genes & Genomes. Cuscuta exaltata, at least, has retained most of the genes associated with photosynthesis, perhaps because of their involvement in lipid synthesis (McNeal et al. 2007). However, gene loss can be quite extensive, many protein-encoding genes being lost in some holoparasitic clades (Braukmann et al. 2013; see also Krause 2011). Mitochondrial genes, at least, can move from Cuscuta to its host, and example being in Plantago (Mower et al. 2010).
Chemistry, Morphology, etc. Glycine betaines are rather commonly accumulated in Convolvulaceae (Rhodes & Hanson 1993), perhaps surprising since it is not a family of halophytes. Wood fluorescence occurs, but not often. Humbertia has hard wood with the odor of sandalwood. Successive cambia have been reported from some species of Ipomoea (Terrazas et al. 2011). Adventitous roots on the stem may develop in two lines sublateral to and below the petiole.
The bracts may be adnate to the pedicel and accrescent (wind dispersal: Neuropeltis), or the bracteoles may be much enlarged (e.g. Calystegia). Some Convolvuloideae have flowers with slight oblique disymmetry (Lefort 1951), while the zygomorphy of the flowers of Humbertia is largely positional, indeed, they are drawn as being polysymmetric by Pichon (1947). The sepals of Humbertia have five traces, but in Convolvuloideae there are fewer; secretory cells are apparently restricted to the flower (Deroin 1993). The corolla tube of some Cuscuta and some other members of the family is strictly speaking a corolla-stamen tube, both contributing integrally to the tubular structure (Prenner et al. 2002). The infrastaminal scales found in Cuscuta may protect the nectar or the ovary (Riviere et al. 2013). Weberling (1989) described the ovary as being fundamentally gynobasic, although with an apical septum. The seed coat is perhaps the most complex of that of any other [asterid I + II], being up to about 30 cells thick and consisting of several types of cells, some much thickened and lignified; see Govil (1971) and Kaur and Singh (1987) for details. There are a few, mostly old records of protein crystalloids in the nucleus (Speta 1977; Thaler 1966).
Cuscuta: For competition between embryo sacs, see Sastri (1956), Johri and Nand (1935: parietal cells), Tiagi (1951), Johri and Tiagi (1952), and Vázquez-Santana et al. (1992) for embryology, flower and fruit; Sherman et al. (2008) for germination; and Welsh et al. (2010) for pollen. For the diversity of style and stigma morphology in Cuscuta, which encompasses that of the whole family, see Wright et al. (2011). General references include Kuijt (1969), Heide-Jørgensen (2008), the Parasitic Plants website (Nickrent 1998 onwards) and the Digital Atlas of Cuscuta (Costea 2007 onwards).
For chemistry, see Hegnauer (1964, 1989) and Eich (2008), for seed reserves, see G. Dahlgren (1991), for the rpl2 intron, Downie et al. (1991) and Stefanovic et al. (2002), for ovary morphology, see Deroin (1999b), for floral anatomy, Deroin (2004 and references), for embryology, see Raghava Rao (1940), Kaur (1969), Kaur and Singh (1970) and Yana and Rao (1993), for the chloroplast ycf15 gene, see McNeal et al. (2007), for general information, see Staples and Brummitt (2007), for successive cambia, etc., see Rajput et al. (2008). Some information about Humbertia is taken from Pichon (1947) and K. Kubitzki and H. Manitz (pers. comm.), but the genus is poorly known, especially embryologically. For general information, see Hoogland (1953b) and especially Convolvulaceae Unlimited.
Phylogeny. The distinctive Humbertia is sister to the rest of the family (e.g. Refulio-Rodriguez & Olmstead 2014). Within Convolvuloideae, part of Poraneae (Cardiochlamyeae: Porana itself is polyphyletic), Erycibeae s. str., and a clade made up of all other Convolvuloideae form a basal trichotomy. Erycibe in particular can look very unlike other members of the family and herbarium specimens are often misidentified. Within the third clade, Ipomoea, Convolvulus, and their relatives form a clade that is sister to a rather unexpected clade made up of Poraneae, Cresseae, Dichondreae (with gynobasic styles), some Erycibeae (Maripeae), etc., as well as Jacquemontia. Several members of this latter clade have styles divided to the base or only an at most shortly connate style with long branches (but Jacquemontia, etc., have a long style), and leaf blades with more or less pinnate venation; Jacquemontia could be sister to the other taxa. Despite the sequencing of over 6800 bp, the position of Cuscuteae remains unclear (Stefanovic & Olmstead 2001, 2004; Stefanovic et al. 2002 and esp. 2003), however, they may be close to a clade containing species with bifid styles (Wight et al. 2011). For a morphological phylogeny of the family, see Austin (1998).
For relationships within Cuscuta, see e.g. Stefanovic et al. (2007), García and Martín (2007), Stefanovic and Costea (2008) and Braukmann et al. (2013). Species limits in Cuscuta are difficult (Costea & Stefanovic 2009); see Costea et al. (2011) and references for recent work on the genus.
Ipomoea is very much paraphyletic. Within it there is a well-supported spiny pollen clade that comprises some 50% of the larger Ipomoea clade (Manos et al. 2001a). There seem to be two main clades in a largely monophyletic Convolvulus, although C. nodiflorus did not link with the rest (Carine et al. 2004: sampling needs to be extended).
Classification. For the tribes above, some of which may be paraphyletic, see the useful classification in Stefanovic et al. (2003). What to do with Ipomoea - to split, or to lump (Ipomoea = Ipomoeeae) - is difficult, and none of the options is without its drawbacks (Stefanovic et al. 2003). In the synonymy, both s. str. and s.l. options are given.
SOLANACEAE Jussieu, nom. cons. Back to Solanales
Herbs to shrubs, branching sympodial; hygroline alkaloids, oligosaccharides, (myricetin) +; roots diarch [lateral roots 4-ranked]; (hairs branched/stellate); wood commonly fluoresces; pits vestured; crystal sand +, esp. in stem; cystoliths +; stomata various; leaves simple to compound; branching/leaf insertion in inflorescence distinctive; (flowers 4 merous); anthers often dehiscing by pores, or ± connate and pollen exiting communal apical hole, endothecial thickenings reticulate; G [(-5)], oblique, often pseudo-4-locular, stigma capitate or peltate, wet; ovules usu. many/carpel, often campylotropous; embryo sac with chalazal haustorium; exotestal walls thickened usu. on inner periclinal and anticlinal walls, endotesta [= endothelium] ± persistent, walls ± lignified; endosperm (helobial, nuclear) +, cotyledons and radicle same width; chromosomes 1-3 µm long, protein bodies in nuclei.
102[list]/2460 - 8 clades below, but treatment needs work. World-wide, but overwhelmingly tropical America (map: from van Steenis & van Balgooy 1966; Meusel et al. 1978; van Balgooy 1984; Heywood 2007).
Age. Crown Solanaceae have been dated to (45-)41, 36(-32) m.y. (Wikström et al. 2001); Janssens et al. (2009) date them to 58±9.1 m.y., Paape et al. (2008) to ca 51 m.y., and Bell et al. (2010) to (49-)38, 37(-29) m.y.a.; still younger estimates are around 35 m.y. (Dillon et al. 2009), and (34.0-)30.4(-26.3) m.y. (Särkinen et al. 2013).
1. Schizanthoideae Hunziker
Annual herbs; tropane alkaloids +; cork pericyclic; pericycle fibres 0; flowers strongly monosymmetric, abaxial pair of C connate, forming a keel; A 2 [abaxial-lateral], staminodes 3; fruit a septicidal capsule; endosperm nuclear, embryo curved; n = 10.
1/12. Chile. [Photo - Schizanthus Flower.]
Age. Crown Schizanthoideae have been dated to slightly over 5 m.y., certainly under 10 m.y. (Särkinen et al. 2013).
2. Goetzeoideae Thorne & Reveal
Trees to shrubs; pollen tricolpate, exine echinate, tectum perforate; fruit often a drupe; endosperm at most slight, cotyledons large, fleshy [Goetzea, etc.]; n = 12, 13.
6/8. Most Greater Antilles, but not Jamaica, east Brazil, Madagascar (Tsoala). [Photo - Flower.]
Synonymy: Goetzeaceae Miers
Age. A clade including Duckeodendron been dated to (39-)35, 33(-29) m.y. (Wikström et al. 2001).
3. Duckeodendron Kuhlmann
Tree; wood with large, open, radial canals [c.f. Apocynaceae s. str.]; 1 ovule/carpel; fruit a one-seeded drupe; endosperm slight, embryo U-shaped, cotyledons small; n = ?
1/1: Duckeodendron cestroides. Amazonian Brazil.
Synonymy: Duckeodendraceae Kuhlmann
3A. Reyesia C. Gay
Annuals to perennial subshrubs; flowers weakly monosymmetric; A 4 or 2 + 2 adaxial staminodes, abaxial stamens with unequal divergent thecae; style spathulate apically, stigma smaller, semidiscoidal; fruit?; embryo coiled, cotyledons incumbent; n = ?
1/4. N. Chile, adjacent Argentina (map: from Hunziker & Subils 1979).
4. Browallioideae Kosteletzky
(Steroid alkaloids - Cestrum); cork superficial or deep-seated; bordered pits +; pericyclic fibres +; A 4 or 5, often didynamous, staminode +/0; (fruit fleshy); exotestal cells somewhat thickened on all walls - Cestrum; n = (7-)11(-13), chromosomes 6-11.5 µm long.
10/210: Cestrum (175). South and Central (and North) America.
Synonymy: Cestraceae Schlechtendal, Salpiglossidaceae Hutchinson
[Schwenkioideae [Petunioideae [Nicotianoideae + Solanoideae]]] (if this clade exists): endothecial thickenings variable.
Annual herbs; pericycle fibres +; flowers monosymmetric, C lobes 3-lobed [Schwenckia and Melananthus]; A 4, didynamous, or 2 + 2 or 3 staminodes; embryo straight, short; n = 10, 12.
4/31. South America.
[Petunioideae [Nicotianoideae + Solanoideae]] (if this clade exists): (tropane alkaloids [calystegines] +); branching particularly distinctive...
Age. This node has been dated to (28-)25, 23(-20) m.y. (Wikström et al. 2001).
Herbs to shrubs; (cork deep-seated); bordered pits +; pericyclic fibres +(0); druses 0(+); (flowers monosymmetric); A 4(-5), usu. of two lengths; embryo also slightly curved; n = 7-11.
13/160: Brunfelsia (45), Petunia (35). Central and South America.
[Nicotianoideae + Solanoideae]: (nicotine [pyridine alkaloid] +); stigma wet; (cotyledons accumbent); x = 12; genome duplication event.
Age. The age of this clade has been estimated at ca 23.7 m.y. (Wu & Tanksley 2010; Wang et al. 2008), (17-)14, 12(-9) m.y. (Wikström et al. 2001), (25.7-)24.0(-23.0) m.y. (Särkinen et al. 2013), and (72.8-)44.7(-23.0) m.y. (Eserman et al. 2013).
7. Nicotianoideae Miers
Mostly herbs; cork superficial; pericyclic fibres +/0; A 4 (staminode +), 5, (of two lengths); embryo straight (curved), radicle short; n = (7-11).
8/125: Nicotiana (95). Mostly Australian, also North and South America, Africa.
Synonymy; Nicotianaceae Martynov
8. Solanoideae Kosteletzky
Herbs (to small trees); (withanolides [steroidal lactones] +); pits not vestured; (crystal sand +) [level?]; A 5 (4), (of different lengths), base of the filament [stapet] often enlarged, with lobes, etc.; (pollen surface striate - Anthocercis); (style gynobasic; G 3, or subdivision of carpels into 1-seeded units - "Nolanaceae"); integument 7-13 cells across; fruit a berry (drupe; circumscissile capsule - Hyoscyameae; schizocarp; K highly accrescent); seeds flattened; (exotestal cells anticlinally elongated); endosperm cellular, embryo curved, often coiled; (n = 10-15), chromosomes 1-14 µm long.
62/1940: Solanum (1250-1700), Lycianthes (200), Lycium (90), Nolana (90), Physalis (80). World-wide, but esp. South America and others N. temperate. [Photo - Flower, Iochroma Flower, Przewalkskia Fruiting Calyx.]
Age. The age of crown Solanoideae has been estimated at (23.3-)21.0(-19.0) m.y. (Särkinen et al. 2013).
Synonymy: Atropaceae Martynov, Browalliaceae Berchtold & J. Presl, Daturaceae Berchtold & J. Presl, Hyoscyamaceae Vest, Lyciaceae Rafinesque, Nolanaceae Berchtold & J. Presl, nom. cons., Sclerophylacaceae Miers
Evolution. Divergence & Distribution. Solanaceae have had a New World origin, with perhaps 8-9 dispersal events to the Old World (Tu et al. 2010). Olmstead (2013) suggested that ten clades were involved, but could not find any connection between likelihood of dispersal and disseminule type (dry versus fleshy). The early-diverging clades in the family are currently temperate and/or Andean in distribution, perhaps reflecting the original climatic preferences of the family (Olmstead 2013: much more on possible niche conservatism here).
The crown-group age of Solanum (inc. tomato and eggplant) is ca 15.5 m.y. (add Capsicum - ca 19.6 m.y.: Wu & Tanksley 2010; Wang et al. 2008); Paape et al. (2008: HPD, see also estimates for other nodes) gave ages of (20.6-)16.1(-12.2) m.y., while (17.5-)15.5(-13.3) m.y. ((18.7-)17.0(-14.5 m.y. - Jaltomata sister, (21.0-)19.1(-17.0) m.y. - Capsicum) is the estimate in Särkinen et al. (2013, q.v. for much else). Dillon et al. (209) discuss the evolution of Nolana, a speciose clade of the coastal deserts (lomas) in the Atacama Desert of western South America; it was perhaps originally from Peru.
Soltis et al. (2009) suggest that diversification in Solanaceae may be connected with a gene duplication in the family; they place it as an apomorphy of the species-rich Solanoideae, although with hesitation - however, ages for the event vary, and it may have nothing particularly to do with Solanaceae at all (see below). For evolution of fruit and flower types, etc., see Knapp (2002) and Knapp et al. (2004), and for the evolution of floral scent, see Martins et al. (2007).
Ecology & Physiology. Solanaceae are an important component of understorey vegetation in l.t.r.f. of the New World.
Plant-Animal Interactions. Most Solanaceae synthesize a variety of metabolites that defend the plant against herbivores; these include nicotinoids, capsaicinoids, steroidal alkaloids, and withanolides of varying degrees of toxicity (Wink 2003). Nevertheless, New World Solanaceae are eaten by larvae of some 360 species of Nymphalidae-Danaeinae-Ithomiini (or Ithomiinae) butterflies, and they seem to have switched host plants from Apocynaceae (Ehrlich & Raven 1964; Drummond & Brown 1987; Willmott & Freitas 2006: I do not know if Schizanthoideae, Goetzeoideae and Schwenkioideae are eaten). Strict co-evolution seems not to be involved, but the diversification rate of the butterflies seems to have temporarily increased with this shift (Fordyce 2010). The move on to Solanaceae has been estimated at 46-37 m.y.a. (Nylin et al. 2013 and references), and diversification began at middle elevations on the Andes in the middle Miocene some 15 m.y.a.; Solanaceae are common all along the Andes today (Elias et al. 2009). Solanum itself is especially important as a food source for caterpillars of this group (ca 70% records of neotropical Solanaceae food sources, ca 89% those of all Ithomiini: Willmott & Freitas 2006; see also Brower et al. 2006). Interestingly, most species of Solanaceae in the more diverse communities are eaten by ithomiine larvae, perhaps suggesting that the host plant niche is almost saturated by the butterfly (Willmott & Elias, in Elias et al. 2009). Some larvae may be distasteful because of the alkaloids, etc., of the leaves they eat, and the noxious solanaceous chemicals also guide oviposition and the feeding preferences of the larvae: "Though the butterflies may be able to recognise their food plants, biologists have greater difficulty in Solanaceae identification" (Brown 1987, p. 373).
Ithomiine butterfies are also distasteful, but not because of these alkaloids, but rather because of the dihydroxypyrrolizidines that the adults obtain especially from Apocynaceae, Boraginaceae-Heliotropioideae and Asteraceae-Asteroideae (especially Eupatorieae). The butterflies are quite palatable immediately after hatching, but that soon changes, and massive amounts (ca 20% dry weight) of these chemicals may be sequestered (Brown 1987). The mimicry rings in which Ithomiini are involved may be associated with particular solanaceous host plants (Willmott & Mallet 2004).
Tobacco hornworm caterpillars prefer members of the [Solanoideae + Nicotianoideae] clade as food sources, although they didn't like Nicandra much; they died on Petunia, and didn't grow on Browallia and Brunfelsia. Other plant feeders show similar distinctive patterns (e.g. Fraenkel 1959), thus other sphingids are found here and on Oleaceae (Forbes 1958). Phytophagous Chrysomelidae beetles (perhaps especially Criocerinae) are notably more common on New World than Old World Solanaceae, perhaps because the beetles first used the family as a food source in the former area (Jolivet & Hawkeswood 1995; see also Hsiao 1986); Criocerinae may have moved onto Solanaceae from monocots. Chrysomelinae and Megalpodinae are also found on New World Solanaceae (Jolivet 1988). The larvae are covered by faecal shields (Vencl & Morton 1999; see Gómez-Zurita et al. 2007). In general, Solanaceae have multiple lines of defence and are avoided by most insect herbivores (Harborne 1986; Hsiao 1986).
Touch-sensitive trichomes are common in Solanoideae (or they have simply been most studied there), and glandular hairs are common, as well as many other hair types (see Seithe 1962; Seithe & Sullivan 1990 and references for hair morphology, esp. in Solanoideae). Insect-deterrent secretions are produced when these hairs are brushed by the insect; these secretions may contain poisonous metabolites, or they may rapidly oxidise and become sticky, so trapping and killing small insects, or secretion in these hairs may hydrolyse, so attracting other insects that target the caterpillars eating the plant (van Dam & Hare 1998 and references; Kellogg et al. 2002; Weinhold & Baldwin 2011). Mutants of tomatoes lacking the protective metabolites have been found to be susceptible to herbivory in the field (Kang et al. 2010).
Pollination Biology & Seed Dispersal. Knapp (2010) summarises information on pollinators and basic floral morphology of Solanaceae. More or less well developed monosymmetry is quite common in Solanaceae, and is of the 3:2 sort (see Eichler 1875; Robyns 1931; Cocucci 1989; Knapp 2002a; Ampornpan & Armstrong 2002). The complex flower of Schizanthus is described as having oblique rather than inverted symmetry (Cocucci 1989b: functionally equivalent), and dehiscence of the two functional anthers is explosive (Cocucci 1989a). For floral evolution in the genus, not very speciose, see Pérez et al. (2006: midpoint rooting), and for CYC gene expression, see Preston et al. (2011b). Nierembergia (Petunioideae) has oil flowers (Coccucci 1991; see Tate et al. 2009 for a phylogeny). A number of taxa have quite large and complex stigmas (Cocucci 1991, 1995).
Within Solanoideae, the Andean Iochrominae are notably diverse florally and have a variety of pollinators (Smith & Baum 2006). Zygomorphy and heteranthy, which in this context is really a kind of zygomorphy, have evolved several times in Solanum, also in other Solanoideae like Sclerophylax, etc. (Bohs et al. 2007). In heteranthous flowers some of the anthers are feeding anthers, while others deposit pollen on the pollinator in such a way that pollination can take place (Stern & Bohs 2012). Buzz pollination is common in Solanum (see Teppner 2005: pollination of the tomato; Harter et al. 2002; García et al. 2008), and over a million pollen grains can be produced by a single flower (Anderson & Symon 1988); the corolla is often rotate, the flowers lack nectar and the anthers dehisce by terminal pores, all features of buzz-pollinated flowers. A number of Solanoideae have capillary nectary grooves on the bases of the petals along which nectary moves, sometimes to dark spots on the corolla whence it can be removed (Dong et al. 2013).
Solanaceae have a gametophytic incompatibility mechanism; the common ancestor of the family is likely to have had RNase-based self incompatibility (SI) (Paape et al. 2008). The evolution of self-compatability (SC) has since occurred many times, but never the reverse; overall diversification of SI clades is greater than that of SC clades, yet SC species are frequent because of the frequency of the SI -> SC transition (Goldberg & Igic 2012: scoring of dioecious taxa?; Goldberg et al. 2010). The evolution of polyploidy and self-compatibility in the family are correlated (Miller at al. 2008; Roberston et al. 2010), interestingly, there was effective dispersal of SI Lycium to Africa, with subsequent restoration of diversity of SI alleles following the dispersal-caused bottleneck (Miller et al. 2008).
Seed dispersal very much follows what fruit morphology might suggest (Knapp 2002b for a summary). In the New World Solanum in particular, with its relatively nutritious fruits, is an important food source for Stumira, a phyllostomid bat (Fleming 1986; Lobova et al. 2009 for records). The bats are slow feeders and spit out seeds, fibre, etc.; Solanum, like other bat-dispersed taxa in the New World, tend to be early successional plants (Muscarella & Fleming 2008), and the altitudinal ranges of the bats and plants are similar (Fleming 1986). The berries of Solanum sect. Gonatotrichum are explosive... (Stern & Bohs 2012).
Bacterial/Fungal Associations. The distinctively pungent capsaicanoids of chilis (Capsicum spp.) are involved in the protection of the fruit against the fruit-destroying Fusarium fungus (Tewksbury et al. 2008). Capsaicins can be synthesized by the ascomycetous endophytic fungus Alternaria (Devari et al. 2014).
Genes & Genomes. A genome duplication event in Solanaceae has been dated to ca 50-52 m.y. (Schlueter et al. 2004), a genome triplication (?the same) at (90.4-)71(-51.6) m.y. (Tomato Genome Consortium 2012), and a duplication event at 23-18 m.y. (Blanc & Wolfe 2004). Schranz et al. (2012) suggested that there was a lag time between a duplication event that characterized the [Nicotianoideae + Solanoideae] clade and the diversification of that clade, largely represented by the speciose Solanoideae. However, Wu et al. (2006) dismissed the possibility that there had been a genome duplication either on the branch leading to or within Solanaceae (see also Robertson et al. 2010), although they allowed the possibility of a duplication well before the the divergence of Solanales and Gentianales.
Wu and Tanksley (2010) have reconstructed the ancestral genome of the [Nicotianoideae + Solanoideae] clade, and the various changes involved in the genomes of Nicotiana, tomato, pepper, etc. One or more functional genes from Agrobacterium rhizogenes are found in many, but not all, species of Nicotiana and may have coevolved with the plant genome (Intrieri & Buiatti 2002); horizontal gene transfer is relatively quite common in Solanaceae (Talianova & Janousek 2011). It has also occurred in the mitochondrial Cox-1 intron both within the family and from outside (Sanchez-Puerta et al. 2011). Within Nicotiana, there has been reticulate evolution both at the diploid and polyploid level, as was evident in an attempt to understand the origin of allopolyploid species of the section Suaveolentes (Kelly et al. 2012).
Petunia and Hyoscyamus, in different subfamilies, can be intergrafted (Taiz & Zeiger 2006).
Economic Importance. Chillies (Capsicum annuum) were domesticated in Mexico, quite possibly in a number of places (Aguilar-Meléndez et al. 2009); other species of the genus are also economically important (Perry et al. 2007 and references); for the domestication of the tomato, see Bai and Lindhout (2007).
Chemistry, Morphology, etc. Lycium is recorded as accumulating glycine betaines, and some members at least are halophytic (Levin & Miller 2005). For alkaloids in Datureae, see Doncheva et al. (2006), and for withanolides, see Burton and Oberti (2000). Schizanthoideae have distinctive tropane alkaloids, hairs, and pollen (Hunziker 2001).
Unusual stomata with degenerate guard cells have often been reported in the family (Cammerloher 1920; D'Arcy & Keating 1973). Leaves in the fertile part of the stem of Solanaceae, perhaps especially in Solanoideae, are often geminate and/or branching is not simply axillary; Petunia can have ordinary-looking cymose inflorescences, but Schwenkia, Schizanthus and many other taxa have more or less recaulescent bracts, only one branch of the cymose inflorescence is developed at each node, or the two branches develop in different ways, etc., making interpretation of the construction of the plant difficult (see especially Danert 1958, 1967; Child & Lester 1991 for a brief summary; Bell & Dines 1995). Castel et al. (2010) suggest similarities between inflorescences of at least members of Petunioideae and Solanoideae; they note that the absence of bracts here may be only apparent. The growth pattern of ex-Nolanaceae is very like that of other Solanoideae (see also Eichler 1874). Goetzea has an odd growth pattern; its leaves are rather xeromorphic.
Knapp (2010) surved the considerable floral diversity in Solanaceae. Heterotopy of a foliar gene may be involved in the development of the notably inflated calyx surrounding the fruit in Physalis (He & Saedler 2007; c.f. Hu & Saedler 2007); inflated calyces occur in some nine genera, although details of the pattern of evolution - and perhaps also loss - of this feature are unclear. In floral development, petal and stamen primordia together are lifted by zonal growth and the carpel primordia develop on a flat apex; in this respect there are some similarities between Solanaceae, Scrophulariaceae and Gesneriaceae, few with Montiniaceae (Huber 1980: 66-69; Ronse Decraene et al. 2000). For floral development in Datureae, see Yang et al. (2002). The flowers of Nolana have two long and two short stamens. The patterns of endothecial thickenings in the family are very diverse (Carrizo García 2002).
The two carpels so common in Solanaceae (but Nicandra has 3-5 while and Nolana many more) are often in the plane of the first sepal initiated; this is one of the abaxial pair. Indeed, the basic plane of symmetry in flowers like Salpiglossis and Schizanthus may be monocotyledonous, and the "abaxial" one or three stamens are sterile (see also Ampornpan & Armstrong 2002 for floral symmetry). For a detailed study of the frequent loss of gametophytic incompatibility in Solanaceae, see Igic et al. (2006). Androgenesis, an uncommon condition in which the male gamete in maternal cytoplasm produces an embryo, has been recorded for at least one member of each of the three subfamilies Petunioideae, Nicotianoideae and Solanoideae - Petunia, Nicotiana, and Capsicum (Chat et al. 2003 for references).
Arabidopsis-type telomeres are absent from some Browallioideae (Sýkorová et al. 2003a). Cestreae in particular, which lack these telomeres, have chromosomes that at 7.21-11.51 µm long are considerably larger than those of the rest of the family, which are much smaller, e.g. 1.5-3.52 µm long in Nicotianoideae (Acosta et al. 2006; Tate et al. 2009); Cestreae also have n = 8 (Las Penas et al. 2006).
For generic descriptions and much else, see Hunziker (2001); Goodspeed (1954) remains the classic account of Nicotiana. For general chemistry, see Hegnauer (1973, 1990, also 1966, 1990 as Nolanaceae) and Eich (2008), for the evolution of secondary metabolites, see Wink (2003 and references), and for calystegines (tropane alkaloids), see Dräger (2004), for wood anatomy, see Carlquist (1987a, 1988a) and Jansen and Smets (2001: vestured pits - do Petunioideae and Nicotianoideae have them?), and for branching patterns, see Danert (1958). For floral vascularization, see Liscovsky et al. (2009 and references), for floral development, see Sattler (1977), for floral and inflorescence morphology, see Huber (1980), for embryology, see di Fulvio (1969: Nolana), for seed coat morphology and development, see Souèges (1907: he described the chalazal end of the embryo sac as herniating), for pollen morphology of zygomorphic taxa, see Stafford and Knapp (2006: not integrated with phylogeny), and of Hyoscyameae, see Zhang et al. (2009), for the diverse patterns of endothecial thickening, see García (2002), for fruit anatomy, see Pabon Mora and Litt (2007), and for chromosome numbers in Solanoideae, see Robertson et al. (2010) and Chiarini et al. (2010). For details of the distinctive Sclerophylax, see di Fulvio (1961).
Phylogeny. For early studies of relationships, see Olmstead & Palmer (1992) and Fay et al. (1998b). The grouping [Petunioideae [Solanoideae + Nicotianoideae]] is well supported in Olmstead et al. (1999), although less so in Olmstead and Santiago-Valentin (2003). However, in the summary tree of Olmstead and Bohs (2007), immediately below the clade [Solanoideae + Nicotianoideae]was a polytomy including Petunioideae, Cestroideae and Schwenkioideae (see Dillon et al. 2009 for another topology). Relationships between these latter clades had only weak support; Schwenkia might be sister to the rest of the family (Olmstead et al. 1999). However, using the nuclear gene SAMT (salicylic acid methyl transferase), Martins and Barkman (2005) found Schizanthus in this position, and with rather strong support, with Schwenkia weakly linked with Cestroideae (see also Olmstead & Bohs 2007). The Goetzioideae clade in the past has included Duckeodendron as sister to the rest, but with only moderate support (Santiago-Valentin & Olmstead 2001, 2003); here its relationships are unresolved. Wu et al. (2006) found a strongly supported grouping of [Solanoideae [Petunioideae + Nicotianoideae]], and although in this case no other clades of the family were included, the sequences analyzed came from ten orthologous loci each on a different chromosome. The two-gene tree in a recent study by Olmstead et al. (2008) is rather like that of Martins and Barkman (2005): [Schizanthoideae [Goetzioideae, Duckeodendron [[Cestroideae/Browallioideae, including Benthamiella et al.; their relationships have previously been unclear], Petunioideae, Schwenckioideae [Nicotianoideae + Solanoideae]]]], but support is strong for relationships between the last pair of taxa alone. Särkinen et al. (2013) added Reyesia to the taxa at the base of the tree whose inter-relationships are uncertain. Indeed, in this last study, [Petunioideae + Nicotianoideae] was the only well supported clade along the spine, although there was a weakly supported [Schwenkieae, Petunioideae, Cestroideae], even if in the latter it was unclear if Benthamiella was to be included. In the tree used for dating clades, Schwenkieae were sister to the whole family, which in turn consisted of two clades [Nicotianoideae + Solanoideae} and the rest (Särkinen et al. 2013).
Within Solanoideae, the limits of Solanum are to be expanded to include Cyphomandra and Lycopersicon; the hairs are often stellate and prickles are common (see Bohs 2005, 2007; Levin et al. 2006; Weese & Bohs 2007 [three genes, S. thelopodium sister ro rest, or unresolved in Bayesian analysis], Botany 2008: Botany without Borders 120-121. 2008; Poczai et al. 2008; Särkinen et al. 2013: Thelopodium sister to the rest). Relarionships within the speciose subgenus Leptostemonum, characterised by stellate hairs and prickles, are outlined by Stern et al. (2011) and Vorontsova et al. (2013: African taxa). Jaltomata is sister to Solanum; major clades in the former genus are characterised by fruit colour (Miller et al. 2011). For relationships within the distinctive Nolana, in the past often separated and placed in Nolanaceae because of its gynoecium, see Tago-Nakawaza and Dillon (1999), Dillon et al. (2007, 2009) and Tu et al. (2008). The distinctive Sclerophylax is also to be included in Solanoideae (Olmstead et al. 2008); it has sessile flowers, an inferior obliquely-oriented ovary with 2-3 ovules per carpel that are pendulous from the upper part of the loculus, and the calyx is accrescent, spinescent, and surrounds the 1-3-seeded fruit.
Lycium may be paraphyletic and will need to be expanded to include Phrodus and Grabowskia (Levin & Miller 2005; Levin et al. 2007; Levin et al. 2009). For the phylogeny of Brunfelsia, which moved onto the Antilles, where it radiated, from South America, see Filipowicz and Renner (2012).
Classification. For the main outlines of the classification above, see Olmstead et al. (2008). For the circumscription of Lycium, see Levin et al. (2011). Solanaceae Source includes information currently mostly about Solanum, but its coverage will expand.
Previous Relationships. Huchinson (1973) placed Duckeodendraceae in Boraginaceae, but doubtfully; Cronquist (1981) kept it as a poorly-known family; Takhtajan (1997) placed it as a separate family in Solanales. Its carpels are oblique to the main axis of the flower (Kuhlmann 1934), as is appropriate for a genus in Solanaceae. Nolanaceae have often been separated from Solanaceae because of their distinctive gynoecium; there are basically five carpels borne opposite the petals, but their number secondarily increases.