EMBRYOPSIDA Pirani & Prado (crown group)

Gametophyte dominant, independent, multicellular, thalloid, with single-celled apical meristem, showing gravitropism; flavonoids + [absorbtion of UV radiation]; protoplasm dessication tolerant [plant poikilohydric]; 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 [with respect to long axis of archegonium/embryo sac], 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 multilamellate]; 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.

STOMATOPHYTES

Abscisic acid, ?D-methionine +; sporangium with seta, seta developing from basal meristem [between epibasal and hypobasal cells], sporangial columella + [developing from endothecial cells]; stomata +, anomocytic, cell lineage that produces them with symmetric divisions [perigenous]; underlying similarities in the development of conducting tissue and in rhizoids/root hairs; 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/sunken 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.

POLYSPORANGIOPHYTA

Sporophyte well developed, branched, free living, sporangia several; spore walls not multilamellate [?here]; apical meristem +.

EXTANT TRACHEOPHYTA / VASCULAR PLANTS

Photosynthetic red light response; water content of protoplasm relatively stable [plant homoiohydric]; control of leaf hydration passive; (condensed or nonhydrolyzable tannins/proanthocyanidins +); vascular tissue +, sieve cells + [nucleus degenerating], tracheids +, in both protoxylem and metaxylem; endodermis +; root xylem exarch [development centripetal]; stem with an apical cell; branching dichotomous; leaves spirally arranged, blades with mean venation density 1.8 mm/mm2 [to 5 mm/mm2]; sporangia adaxial on the sporophyll, sporangia derived from periclinal divisions of several epidermal cells, wall multilayered [eusporangium]; columella 0; tapetum glandular; 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 apex multicellular, root cap +; tracheids with scalariform-bordered pits; leaves 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].

LIGNOPHYTA

Plant woody; lateral root origin from the pericycle; branching lateral, meristems axillary; 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, 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; pollen grains landing on ovule; 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.

MAGNOLIOPHYTA

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, overall growth ± diffuse, venation hierarchical-reticulate, secondary veins pinnate, 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; tapetal 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 grains landing on stigma, bicellular at dispersal, mature male gametophyte tricellular, 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]; protoplasm dessication tolerant [plant poikilohydric]; 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).

MAGNOLIIDS + CHLORANTHALES + EUDICOTS: Benzylisoquinoline alkaloids +.

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?

THIS LOT (but getting fewer and fewer) UNPLACED  Main Tree, Synapomorphies.

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...

Maesaceae [Theophrastaceae [Myrsinaceae + Primulaceae]]: (schizogenous secretory canals [material yellow, red, brown: tannins, etc.]); nodes ?3:3; (stomata anisocytic); small ± immersed often peltate glandular hairs +; inflorescence racemose; C and A from common primordia, C connate, stamens = and opposite C, antesepalous whorl represented by at least a vascular trace [?Maesa], nectary +; G [5], opposite C, placentation free-central, ovules at least partly immersed in swollen placenta, apotropous, bitegmic, micropyle bistomal, endothelium +, tanniniferous, style short, hollow, stigma ± capitate; seeds angled; endotesta crystalliferous; endosperm nuclear, copious, cell walls thick, with amyloid or hemicellulosic.

Evolution. Wikström et al. (2001) suggest a stem group age of 75-72 m.y. before present, with crown group divergence beginning 49-46 m.y. before present.

Members of this group are not often eaten by butterfly larvae, but Lycaenidae-Riodininae-Hamearini and a few Riodinini (see also Abisara) are found on them, especially on Maesaceae but not so far on Samolus and Theophrastaceae (Ehrlich & Raven 1964).

Chemistry, Morphology, etc. Leaves of Theophrastaceae and Myrsinaceae are often described as being involute (?supervolute, c.f. Cullen 1978) or conduplicate. There are common stamen/corolla primordia born on a ring primordium in this clade. but there is variation in the position/relative development of these primordia. In some cases such as Cyclamen the stamens are initiated as adaxial outgrowths of a common primordium, i.e. the petal primordia are early larger than the stamen primordia, as also in Myrsine and Aegiceras (see especially Ma & Saunders 2003), whereas the stamen primordia may initially be larger, as in Samolus (e.g. Sattler 1962). However, this is a tricky character, since there are really two variables, the relative positions of these priordia and how fast they initially develop, and, as with evicted terminal inflorescences, initial topolgical relationships between parts can speedily become disrupted by post-initiation growth. The number of carpels can be difficult to ascertain, but five seems to be a common number, however, the orientation is unclear. The diagrams presented by Dickson (1936) mostly suggest that the carpels are opposite the petals, but in Primula, at least, they suggest that the carpels are opposite the sepals.

For the hollow style, see Guéguen (1901: is Maesaceae known?), for staminodes, see Saunders (1936) and Caris and Smets (2004: those of Samolus and Theoprastaceae are developmentally rather different), for nectar secretion, see Vogel (1986, 1997) and Caris and Smets (2004), for embryology especially of the herbaceous taxa, i.e. Primulaceae in the old sense, see Dahlgren (1916), for wood anatomy, see Lens et al. (2005a), and for floral morphology and ontogeny, Dickson (1936: esp. gynoecial arrangement), Sattler (1962), Sundberg (1982), Ronse Decraene (1992), Ronse Decraene et al. (1995) and especially Ma and Saunders (2003). For general morphology, see Anderberg et al. (2000) and especially Ståhl and Anderberg (2004).

Phylogeny. The monophyly of the group is not in doubt (see Anderberg & Ståhl 1994; Anderberg et al. 1998; and especially Källersjö et al. 2000: note that support values for Samolus as sister to Theophrastaceae s. str. are reduced when morphological data are added to molecular).

Phylogeny. This whole group was often recognised as Primulales in the past. Perhaps the only question, particularly in light of the break-up of Primulaceae, the removal of Maesa from Myrsinaceae, the placement/addition of Samolus as sister to the old Theophrastaceae, the many herbaceous ex-Primulaceae that are sister to the old-style, woody Myrsinaceae rather than being in a clade with other Primulaceae, and the numerous features shared by the group as a whole, is whether it is worth recognising families at all... Subfamilial names are already available.

Previous relationships. Plumbaginaceae (see Caryophyllales here) were often associated with Primulaceae and related families because of similar placentation and stamen arrangement (see Cronquist 19181 for discussion).

MAESACEAE Anderberg, B. Ståhl & Kallersjö   Back to Ericales

Evergreen lianes or trees; vessel element type?; petiole bundles all annular; secretory canals well developed; leaves spiral or two-ranked, induplicate, margin toothed to entire; inflorescence often branched; flowers small, C induplicate-valvate, stamen primordium smaller than petal primordium, A basally connate, attached at the middle of the C tube, nectary on G; G [3-4], half inferior, ovules apotropous, endothelium +, stigma truncate or capitate and lobed; fruit a many-seeded drupe, K persistent; testa 2-layered, inner layer with rhombic crystals; n = 10.

Maesaceae

1/150. Old World tropics to Japan, the Pacific, and Australia (map: from Palgrave 2002).

Chemistry, Morphology, etc. Vessels are in radial multiples (as quite commonly in woody Theophrastaceae and Myrsinaceae); there may be groups of druses in the abaxial epidermis; the fibres are septate; and the lateral bundles arise about half an internode below the leaf they supply. Information on floral development is taken from Caris et al. (2000); the ovules are separated by and partly sunken in placental tissue (see also Utteridge & Saunders 2001).

Theophrastaceae [Myrsinaceae + Primulaceae]: herbs[?]; rays ³5-seriate, uniseriate rays 0 [not herbaceous taxa]; bracteoles 0; C imbricate, arising abaxially on common primordium [i.e. stamen primordium > petal primordium], subrotate, tube rather short.

Phylogeny and Evolution. For the suggestion that rosette herbs may be the plesiomorphic condition for this part of the clade, see Anderberg et al. (2001); however, Lens et al. (2005a) find no evidence from wood anatomy that this is likely (apart from in a few Myrsinaceae). Note that in Myrsinaceae, herbaceous taxa such as Stimpsonia, Ardisiandra and Coris are basal to woody taxa, and variation in habit is very extensive in this clade as a whole. Smith and Donoghue (2008) found that the rate of mollecular evolution in the herbaceous taxa they examined was much greater than in the woody taxa.

THEOPHRASTACEAE Link, nom. cons.   Back to Ericales

Bracts displaced up the pedicels; staminodes +, petal-like, endothelium?

6-9[list]/105 - two groups below. Mostly New World and tropical, some also more temperate and Old World (map: from Hultén 1971).

1. Samolus Samolus

Nodes ?1:1; leaves entire; K connate, nectary on ovary; G [5], semi-inferior, style impressed; fruit a 5-valved capsule, seeds many; coat undistinguished, exotesta and endotegmen tanniniferous, the latter crystalliferous; endosperm cell walls thin; n = (12) 13.

1/15. America, the Antipodes, Europe, tropical to temperate (map: from Hultén 1971; Meusel et al. 1978; FloraBase 2005). [Photo - Flowers.]

Chemistry, Morphology, etc. Ståhl (2004) suggests that a secretory system is present, if not always conspicuous. The stomata are anomocytic. There are several petiole bundles forming an arc, and these seem to diverge very soon after the leaf trace departs from the central stele. The ovules completely cover the placenta, but fingers of placental tissue may poke up between them (but not seen in the material examined by Caris & Smets 2004); Ma and Saunders (2003) suggest that in this whole clade (i.e. Theophrastaceae s.l.) the ovules are not embedded (which would then be a synapomorphy for it). The valves of the capsule are opposite the calyx (Caris & Smets 2004).

For general information, see Ståhl (2004: as Samolaceae).

Synonymy: Samolaceae Rafinesque

2. The Rest (Theophrastaceae s. str.)

Woody, tending to be pachycaul; rays broad; nodes also 1:1 [Jacquinia, dividing into three], 5:5 [Clavija]; secretory system?; petiole bundle deeply arcuate or annular, with small adaxial inverted bundles; scale leaves +; leaves conduplicate, margins spiny-toothed to entire, subepidermal fibres +; plant dioecious or flowers bisexual; anthers extrorse, with calcium oxalate, (nectariferous hairs +), style long, stigma dry or wet; fruit a (rather dry) berry, placentae ± pulpy, (drupe); seeds 1-few, rounded, exotestal cells flattened, thick-walled, hypodermal cells (with thickened anticlinal walls), often crystalliferous; endosperm cell walls pitted, cotyledons usu. foliaceous; n = 18, 20, 24.

Theophrastaceae s. str.

4/90: Clavija (50), Jacquinia (35 - perhaps to be divided). New World tropics (map: from Ståhl 1989, 1991, 1995). [Photos - Collection]

  • Theophrastaceae have sympetalous flowers with stamens opposite the petals and five, petal-like staminodes opposite the sepals. Most taxa are woody plants with broad rays and often pseudoverticillate leaves with toothed or spiny margins or a pungent apex. The extrorse anthers form a cone in the center of the flower when it opens, but later spread; the staminodes are more or less petal-like. The subepidermal fibers are visible in the dried leaf as fine striations - use a hand lens!

Chemistry, Morphology, etc. The subepidermal fibres may lack lignification. For reports of glandular dots on calyx and corolla, see Mabberley (1997). Floral primordia may initially be quite strongly monosymmetric, as in Deherania (Sattler 1962), even if the flower at anthesis is polysymmetric.

For morphology, etc., see Ståhl (2004) and in particular Caris and Smets (2004).

Phylogeny. Phylogenetic relationships suggested by Källersjö and Ståhl (2003) imply that some generic realignments are needed.

Primulaceae + Myrsinaceae: two ndhF deletions.

PRIMULACEAE Borkhausen, nom. cons.   Back to Ericales

Cucurbitacins +; ?cork; glands 0, trichomes articulated; leaves involute or revolute, margins entire to dentate or serrate; inflorescence scapose; K often connate, C hypocrateriform; A attached at or above middle of C tube, pollen syn- or polycolpate, nectary on ovary, ovules not immersed in placenta (immersed - Dionysia), (inner integument ca 4 cells across), style usu. long, (heterostyly +); fruit a capsule; seeds many, angled, exotesta ± persistent, walls thickened or not, (endotesta with inner walls thickened [Primula]), endotegmen often crystalliferous; (endosperm cell walls thin); n = 8-12.

Primulaceae

9[list]/900: Primula (490-600: inc. Cortusa, Dionysia [some chasmophytes, for which see Trift et al. 2004, relationships, biogeography; Lidén 2007, revision), Dodecatheon), Androsace (160: inc. Douglasia, Vitaliana, see Schneeweiss et al. 2004b). Northern hemisphere, scattered elsewhere (map: from Hultén 1971; Meusel et al. 1978). [Photo - Dodecatheon flower © R. Kowal] [Photo - Primula flower]

  • Primulaceae are usually rosette herbs with a scapose inflorescence and medium-sized flowers with connate sepals, obviously connate petals, hypocrateriform corolla and stamens borne opposite the corolla lobes; the placentation is free-central and the capsular fruits have numerous, angular seeds.

Evolution. Heterostyly is common, although it is unlikely to be an apomorphy for the family; it is sometimes lost, as in those Primula with buzz pollination, the erstwhile Dodecatheon (Mast et al. 2001, 2006).

Chemistry, Morphology, etc. The involute leaves can be sharply bent rather than incurved (for vernation, see Conti et al. 2000; Mast et al. 2001). Solereder (1908) reports that secretory tissues occur in Androsace lactea. The corolla epidermal cells are isodiametric. Saunders (1936) suggested that some of the lobing of the corolla of Soldanella might be staminodial.

For pollen variation, see Mast et al. (2001), and for general information, see Anderberg (2004).

Phylogeny. For ITS-based relationships within the family, see Martins et al. (2003), and for relationships within Primula, see also Trift et al. (2002) and Mast et al. (2004, 2006), for relationships within Androsace, see Wang et al. (2004) and Schneeweiss et al. (2004b).

Classification. Richards (2003) provides a good general description of the species of Primula s. str.

MYRSINACEAE R. Brown, nom. cons.   Back to Ericales

Also trees to shrubs or lianes; benzoquinones +; (vessel elements with scalariform perforations); (nodes 3:3 - unnamed taxon from Atlantic Forest; Ardisia densiflora); glands/canals throughout the plant (0); leaves (opposite), also supervolute (curved), margins entire (crenate to serrate, teeth cartilaginous); (plant dioecious), inflorescence often fasciculate/corymbose; flowers (3-)4-5(-7)-merous, C often contorted, (nectariferous hairs +); A dorsifixed or basifixed, sagittate, (dehiscing by pores), (micropyle endostomal - Coris; endothelium 0; style 0; long), stigma (punctate), dry or wet; fruit a berry, drupe or capsule [latter in herbaceous taxa], placentae ± pulpy; seeds 1-few, rounded (ruminate; hilum depressed) [woody taxa] or many, small, angular, seed coat undistinguished, (endotesta crystalliferous - Cyclamen), tegmen thickened before becoming crushed, (endotegmen crystalliferous); endosperm walls pitted, (embryo slightly curved; medium); n = 10-13, 15, 17, 23.

Myrsinaceae

41[list]/1435: Ardisia (450), Myrsine (155: inc. Rapanea, Suttonia, many species in the Pacific), Lysimachia (150: sometimes staminodes?, some woody; white flowers with nectariferous hairs, some yellow oil flowers [Macropis the pollinator], or selfers - see Vogel 1986), Discocalyx (115: inc. Tapeinosperma), Embelia (100), Parathesis (85), Stylogyne (60). Pantropical and N. Temperate (map: from Hultén 1958, 1971; FloraBase 2008: S. Hemisphere a bit notional). [Photos - collection woody members, Cyclamen flower © H. Schneider, fruit © H. Schneider], collection of ex Primulaceae.]

  • Myrsinaceae are trees to herbs, and many have distinctive yellowish to blackish dots or streaks on the often spiral leaves and also often obvious on the persistent calyx and on the fruit - I have not seen them on genera like Trientalis, Anagallis (but there may be pigmented spots on the abaxial surface of the lamina), Cyclamen, or some species of Lysimachia. The sympetalous corolla is often contorted, the five stamens are antepetalous, the ovary is superior, and the ovules and/or seeds are immersed in the placenta. In many woody taxa the point of insertion of the branches on the main stem is vertically elongated; growth is often sylleptic.

Evolution. Vogel (1986) discusses pollination, which in a group of yellow-flowered Lysimachia in particular is by oil-collecting Macropis (Mellitidae) bees (see also Simpson et al. 1983). The oil is secreted by trichomes. Anderberg et al. (2007) suggested that Lysimachia with buzz-pollinated flowers and those with nectar-producing hairs formed separate clades and were both derived from oil-producing ancestors.

Some species of Ardisia have pustules along the edge of the leaf blade; although inhabited by bacteria, it is unclear what role the bacteria might be playing (Miller 1990).

For the evolution of the mangrove habitat, to which Aegiceras is restricted, see Rhizophoraceae and Tomlinson (1986). Aegiceras has a number of anomalous anatomical and morphological features, the seed characters in particular are those that might be expected from a mangrove plant, since seeds lack endosperm and contain a large, viviparous embryo (c.f. Rhizophoraceae-Rhizophoreae, Acanthaceae-Acantheae-Acanthus ilicifolius, etc.).

Chemistry, Morphology, etc. The presence of coloured glands may well not be a synapomorphy of the family (Hao et al. 2004). There are breakdown areas in the rays of woody members, and these may be filled with dark contents (Lens et al. 2005). Discocalyx has three traces in the petiole base, and some other taxa may be trilacunar; nodal anatomy needs study. The epidermal cells of the corolla are often elongated (as in Glaux - to be included in Lysimachia - lacks a corolla); this is a derived feature within the family. Trientalis has anisomerous flowers (Swenson et al. 2008c). Cyclamen has one cotyledon and one integument. See Oh et al. (2008) for the seed morphology of herbaceous taxa around Lysimachia.

Coris is a particularly distinctive genus morphologically. It is a small ericoid sub-shrub with monosymmetric flowers that have a spine-tipped epicalyx. There is nectary at the base of the ovary and there are only 5-6 ovules. Monosymmetry is expressed early in development by the calyx, but monosymmetry of the corolla becomes evident only later (Ronse Decraene et al. 1995: they suggest that the median sepal is abaxial, i.e. that the orientation of the flower is inverted or oblique). The rays of Aegiceras are relatively narrow, the ovules are unitegmic, etc. (Staåhl å Anderberg 2004; Lens et al. 2005).

Some information is taken from Otegui and Cocucci (1999) and from Ståhl and Anderberg (2004); Lens et al. (2005a) provide much information about wood anatomy.

Phylogeny. Myrsinaceae, previously circumscribed to include only woody taxa, now include Anagallis, Ardisiandra, Asterolinon (?= Lysimachia), Coris, Cyclamen, Glaux, Lysimachia, Pelletiera, Stimpsonia and Trientalis (Anderberg et al. 2000, 2001; the limits of Myrsinaceae are not so clear in Martins et al. 2003, but ITS data alone in the latter study. Anderberg et al. (2007) was particularly interested in the relationships of the herbaceous taxa; the family as a whole had moderate support as being monophyletic (72% jacknife), and Cyclamen, the herbaceous taxa, and the woody taxa then formed a trichotomy. Hao et al. 2004 also provide a phylogeny of the family, although focusing on Lysimachia.

Classification.Generic limits in the woody members in particular are unsatisfactory, but the limits of genera like Lysimachia are also unclear (Anderberg et al. 2007).

Synonymy: Aegicerataceae Blume, Anagallidaceae Adanson, Ardisiaceae Jussieu, Coridaceae J. Agardh, Embeliaceae J. Agardh, Lysimachiaceae Durande