LIGNOPHYTA
Plant a shrub or tree; true roots +, origin endogeneous, root cap +, apex multicellular; endodermis +; shoot apical meristem multicellular; lateral meristems +, cork cambium producing cork abaxially, vascular cambium producing phloem abaxially and xylem adaxially; lamina with mean venation density 1.8 mm/mm2 (to 5 mm/mm2).
EXTANT SEED PLANTS/SPERMATOPHYTA
Plant woody, 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, thus containing p-hydroxyphenyl and guaiacyl lignin units, so no Maüle reaction; root xylem exarch, cork cambium deep seated; arbuscular mycorrhizae +; shoot apical meristem interface specific plasmodesmatal network; stem with vascular tissue around central pith [eustele], vascular bundles with interfascicular tissue, ectophloic, endodermis 0, xylem endarch; 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"]; vascular bundles collateral [stem: phloem external; leaf: phloem abaxial]; stomata morphology?, pore opening controlled by abscisic acid; 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 tetrahedral, only one megaspore develops, megasporangium indehiscent; male gametophyte development first endo- then exosporic, tube developing from distal end of grain, to ca 2 mm from receptive surface to egg, gametes two, developing after pollination, with cell walls, flagellae numerous; ovules increasing considerably in size between pollination and fertilization, 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 straight, shoot and root at opposite ends [allorrhizic], white, cotyledons 2; plastid transmission maternal; ycf2 gene in inverted repeat, 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, non-hydrolysable tannins, quercetin and/or kaempferol +, 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 unilacunar [1:?]; stomata brachyparacytic [ends of subsidiary cells level with ends of pore], outer stomatal ledges producing vestibule; lamina formed from the primordial leaf apex, margins toothed, development of venation acropetal, secondary veins pinnate, overall growth ± diffuse, venation hierarchical, fine venation 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 not sharply differentiated, with a single trace, outer members not enclosing the rest of the bud, often smaller than inner members; 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 columellar, endexine thin, compact, lamellate only in the apertural regions; nectary 0; G superior, free, several, ascidiate, with postgenital occlusion by secretion, stylulus short, hollow, cavity not lined by distinct epidermal layer, stigma ± decurrent, 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, megaspore tetrad linear, functional megaspore chalazal, lacking sporopollenin and cuticle; female gametophyte four-celled [one module, nucleus of egg cell sister to one of the polar nuclei]; ovule not increasing in size between pollination and fertilization; pollen binucleate at dispersal, 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; germination hypogeal, seedlings/young plants sympodial; Arabidopsis-type telomeres [(TTTAGGG)n]; whole genome 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]]]]]: vessels +, elements with elongated scalariform perforation plates; 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]]]]: essential oils in specialized cells [lamina and P ± pellucid-punctate]; tension wood 0; 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 +; 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 positiion]; embryo sac bipolar, 8 nucleate, antipodal cells persisting; endosperm triploid; ?germination.
[MONOCOTS [CERATOPHYLLALES + EUDICOTS]]: (veins in lamina often 7-17mm/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 scattered, asarone 0 [unknown in some groups, + in some asterids]; root epidermis derived from root cap [?Buxaceae, etc.]; 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]]]: (axial/receptacular nectary +).
[TROCHODENDRALES [BUXALES + CORE EUDICOTS]]: mitochondrial rps2 gene lost.
[BUXALES + CORE EUDICOTS]: ?
CORE EUDICOTS / GUNNERIDAE: (ellagic and gallic acids +); leaf margins serrate; compitum + [one place]; micropyle?; 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 [5], G [3] 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]]: ?
Evolution. Divergence & Distribution. Magallón and Castillo (2009) offer estimates of ca 112.5 and 113.1 m.y. for relaxed and constrained penalized likelihood crown-group ages, comparable ages in Moore et al. (2010: 95% HPD) were (104-)101(-96) m.y..
BERBERIDOPSIDALES Doweld Main Tree, Synapomorphies.
Tension wood?; crystals +; petiole bundle annular; stomata cyclocytic; filaments stout; style +; seed endotestal; endosperm development?, embryo? - 2 families, 3 genera, 4 species.
Note: Possible apomorphies are now being added throughout the site; they 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 because there is very considerable homoplasy, with variation within and between clades, for most characters. Furthermore, the basic information for all too many characters is very incomplete, often 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. Magallón and Castillo (2009) estimate ages of ca 112.5 and 113.1 m.y. for relaxed and constrained penalized likelihood datings respectively for the divergence of stem Berberidopsidales and ca 88.7 and 88.9 m.y. for crown divergence (relaxed and constrained again).
This clade has notably large seeds (Moles et al. 2005a; Sims 2012: 1 species measured).
It has been suggested that the floral development of Berberidopsis corallina is a "link" in the evolution of the flower of core eudicots (Ronse De Craene 2004, 2007), and that the floral morphology of Aextoxicon, with features like rather variable numbers of sepals and petals, both of which are spirally arranged, are also consistent with this (Ronse De Craene & Stuppy 2010). However, if Santalales are basal to Berberidopsidales in the clade immediately leading to the asterids, as in Moore et al. (2010), the significance of such features is less unclear (see also Ronse de Craene & Brockington 2013; Doyle 2013).
Chemistry, Morphology, etc. Carlquist (2003b) details the extensive if probably largely plesiomorphic similarities in the wood of the two families. Possible synapomorphies, however, include the strong differences between the procumbent cells of the multiseriate parts of the rays and the square to upright cells in the uniseriate portions and also the dark-staining deposits in axial parenchyma and rays. Other details of the vegetative anatomy show (apomorphic?) similarities between the two. Aextoxicon has few druses but numerous rhombic crystals presumably of calcium oxalate; Baas (1984) reported crystals in the leaves of all three genera of Berberidopsidaceae, although druses seem to be commonest. For stomatal morphology, see also P. Soltis and D. Soltis (2004).
Phylogeny. There has long been good support for this clade (e.g. D. Soltis et al. 1999: three-gene tree).
Includes Aextoxicaceae, Berberidopsidaceae.
AEXTOXICACEAE Engler & Gilg, nom. cons. Back to Berberidopsidales
Tree; chemistry?; true tracheids +; sclereids +; pith heterogeneous; indumentum of peltate scales; leaves opposite, lamina vernation conduplicate, margins entire; plant dioecious; inflorescence a raceme, (in threes, branching from basal prophylls); flowers (4) 5 (6)-merous, enveloped by bracteoles; K spiral, thin, deciduous, C spiral, broadly clawed; nectary glands reniform, alternating with and internal to A; staminate flowers: stamens = and opposite sepals, filaments relatively stout; G vestigial; carpellate flowers: staminodia +; G 1, stylulus ab?axially curved, apically bilobed; ovules 2/carpel, pendulous, apotropous, micropyle endostomal, outer integument 2-3 cells across, inner integument 5-7 cells across, nucellus massive, strongly beaked, funicle quite long, obturator +; fruit a dry drupe, 1-seeded; seeds carunculate, ruminate; coat tanniniferous, ca 6 cells across, cell walls thin; endosperm +, ?development, embryo ± transverse, long, curved, cotyledons flattened, cordate-orbicular; n = 16.
1[list]/1: Aextoxicon punctatum. C. Chile (map: from Donoso Z. 1994). [Photos - Flower, Flower, Flower, Flower, Fruit, Habit]
Chemistry, Morphology, etc. Sclereids are found in all vegetative parts of the plant; those of the leaf blade are about half the thickness of the blade in length. The stomata are weakly actinocylic, with 5-7 subsidiary cells. The pith is notably heterogeneous. Although the stigma is bilobed, there is only a single carpel (Ronse DeCraene & Stuppy 2010: a flower with two carpels was once seen). The endocarp appears to split particularly readily along two vertical lines. The embryo is more or less transverse to the long axis of the seed.
For some anatomy, see Pax and Hoffmann (1917), for ovule morphology, see Mauritzon (1936), and for a general account, see Kubitzki (2006b). For fruit and stem anatomy, see Gentry et al. 53436, for leaf anatomy, see Solomon & Solomon 4420.
Previous relationships. Aextoxicaceae have been included in a very heterogeneous Celastrales (Cronquist 1981), placed in Euphorbiales (Takhtajan 1997), or linked with Saxifragales (Qiu et al. 1998).
BERBERIDOPSIDACEAE Takhtajan Back to Berberidopsidales
Evergreen woody scramblers; isoleucine-derived cyanogenic glycosides +, ellagic acid 0; cork?; fibers non-septate, pits bordered; wood parenchyma vasicentric or apotracheal; (stomata bicyclic); leaves spiral, lamina vernation involute [Berberidopsis], 2ndry veins palmate, margins spiny-toothed or entire; inflorescences terminal; P +, (9-)12(-15), spiral, all except the outer petal-like, or K and C distinct; nectariferous disc +, lobed, (?0); A 6-many, whorled or irregular, filaments short, anthers inserted along connective, connective with apical prolongation; pollen also tricolpate; G [3, 5], placentation parietal, style stout, hollow, stigma punctate to slightly lobed; ovules 2-many/carpel, epi- or pleurotropous, micropyle bi- or endostomal, outer integument ca 4 cells across, inner integument ca 4 cells across; fruit a berry, K deciduous (persistent - Streptothamnus); (seed with chalazal arilloid - Streptothamnus); exotestal cells enlarged, fleshy, (inner mesotestal cells sclereids), endotestal cells crystalliferous, palisade, lignified, (exotegmen weakly developed, fibrous, lignified), endotegmen subpersistent; endosperm copious, ?development, embryo short; n = ?21.
2/3. Chile, E. Australia (map: from Veldkamp 1984). [Photo - Habit, Flower/Fruit.]
Chemistry, Morphology, etc. Leaves of Berberidopsis are weakly involute in bud and are not at all imbricated. Van Heel (1977) emphasized that the ovules of Berberidopsis were borne directly on the carpel wall, not on placentae as in Salicaceae and Achariaceae. In Streptothamnus there is no necariferous disc - or perhaps it is to be found between the stamens and the gynoecium.
Some information is taken from Miller (1975: anatomy), van Heel (1979, 1984: seed, pollen), Baas (1984: anatomy), Jaroszewski et al. (1998: cyanogenic glycosides), Takhtajan (1992: seed), and Kubitzki (2006b: general).
Previous Relationships. Berberidopsidaceae were included in Flacourtiaceae by Cronquist (1981) and in Violales by Takhtajan (1997) because of their parietal placentation.
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