EMBRYOPSIDA Pirani & Prado
Gametophyte dominant, independent, multicellular, initially ±globular, not motile, branched; showing gravitropism; glycolate oxidase +, glycolate metabolism in leaf peroxisomes [glyoxysomes], acquisition of phenylalanine lysase* [PAL], flavonoid synthesis*, microbial terpene synthase-like genes +, triterpenoids produced by CYP716 enzymes, CYP73 and phenylpropanoid metabolism [development of phenolic network], xyloglucans in primary cell wall, side chains charged; plant poikilohydrous [protoplasm dessication tolerant], ectohydrous [free water outside plant physiologically important]; thalloid, leafy, with single-celled apical meristem, tissues little differentiated, rhizoids +, unicellular; chloroplasts several per cell, pyrenoids 0; centrioles/centrosomes in vegetative cells 0, microtubules with γ-tubulin along their lengths [?here], interphase microtubules form hoop-like system; metaphase spindle anastral, predictive preprophase band + [with microtubules and F-actin; where new cell wall will form], phragmoplast + [cell wall deposition centrifugal, from around the anaphase spindle], plasmodesmata +; antheridia and archegonia +, jacketed*, surficial; blepharoplast +, centrioles develop de novo, bicentriole pair coaxial, separate at midpoint, centrioles rotate, associated with basal bodies of cilia, multilayered structure + [4 layers: L1, L4, tubules; L2, L3, short vertical lamellae] (0), spline + [tubules from L1 encircling spermatid], basal body 200-250 nm long, associated with amorphous electron-dense material, microtubules in basal end lacking symmetry, stellate array of filaments in transition zone extended, axonemal cap 0 [microtubules disorganized at apex of cilium]; male gametes [spermatozoids] with a left-handed coil, cilia 2, lateral, asymmetrical; oogamy; sporophyte +*, multicellular, growth 3-dimensional*, cuticle +*, plane of first cell division transverse [with respect to long axis of archegonium/embryo sac], sporangium and upper part of seta developing from epibasal cell [towards the archegonial neck, exoscopic], with at least transient apical cell [?level], initially surrounded by and dependent on gametophyte, placental transfer cells +, in both sporophyte and gametophyte, wall ingrowths develop early; suspensor/foot +, cells at foot tip somewhat haustorial; sporangium +, single, terminal, dehiscence longitudinal; meiosis sporic, monoplastidic, MTOC [= MicroTubule Organizing Centre] associated with plastid, sporocytes 4-lobed, cytokinesis simultaneous, preceding nuclear division, quadripolar microtubule system +; wall development both centripetal and centrifugal, 1000 spores/sporangium, sporopollenin in the spore wall* laid down in association with trilamellar layers [white-line centred lamellae; tripartite lamellae]; plastid transmission maternal; nuclear genome [1C] <1.4 pg, main telomere sequence motif TTTAGGG, KNOX1 and KNOX2 [duplication] and LEAFY genes present, ethylene involved in cell elongation; chloroplast genome with close association between trnLUAA and trnFGAA genes [precursors for starch synthesis], tufA, minD, minE genes moved to nucleus; mitochondrial trnS(gcu) and trnN(guu) genes +.
Many of the bolded characters in the characterization above are apomorphies of more or less inclusive clades of streptophytes along the lineage leading to the embryophytes, not apomorphies of crown-group embryophytes per se.
All groups below are crown groups, nearly all are extant. Characters mentioned are those of the immediate common ancestor of the group, [] contains explanatory material, () features common in clade, exact status unclear.
POLYSPORANGIOPHYTA†
Sporophyte well developed, branched, branching dichotomous, potentially indeterminate; hydroids +; stomata on stem; sporangia several, terminal; spore walls not multilamellate [?here].
II. TRACHEOPHYTA / VASCULAR PLANTS
Sporophyte long lived, cells polyplastidic, photosynthetic red light response, stomata open in response to blue light; plant homoiohydrous [water content of protoplasm relatively stable]; control of leaf hydration passive; plant endohydrous [physiologically important free water inside plant]; PIN[auxin efflux facilitators]-mediated polar auxin transport; (condensed or nonhydrolyzable tannins/proanthocyanidins +); borate cross-linked rhamnogalactan II, xyloglucans with side chains uncharged [?level], in secondary walls of vascular and mechanical tissue; lignins +; roots +, often ≤1 mm across, root hairs and root cap +; stem apex multicellular [several apical initials, no tunica], with cytohistochemical zonation, plasmodesmata formation based on cell lineage; vascular development acropetal, tracheids +, in both protoxylem and metaxylem, G- and S-types; sieve cells + [nucleus degenerating]; endodermis +; stomata numerous, involved in gas exchange; leaves +, vascularized, spirally arranged, blades with mean venation density ca 1.8 mm/mm2 [to 5 mm/mm2], all epidermal cells with chloroplasts; sporangia in strobili, sporangia adaxial, columella 0; tapetum glandular; sporophyte-gametophyte junction lacking dead gametophytic cells, mucilage, ?position of transfer cells; MTOCs not associated with plastids, basal body 350-550 nm long, stellate array in transition region initially joining microtubule triplets; archegonia embedded/sunken [only neck protruding]; embryo suspensor +, shoot apex developing away from micropyle/archegonial neck [from hypobasal cell, endoscopic], root lateral with respect to the longitudinal axis of the embryo [plant homorhizic].
[MONILOPHYTA + LIGNOPHYTA]Sporophyte growth ± monopodial, branching spiral; roots endomycorrhizal [with Glomeromycota], lateral roots +, endogenous; G-type tracheids +, with scalariform-bordered pits; leaves with apical/marginal growth, venation development basipetal, growth determinate; sporangium dehiscence by a single longitudinal slit; cells polyplastidic, MTOCs diffuse, perinuclear, migratory; blepharoplasts +, paired, with electron-dense material, centrioles on periphery, male gametes multiciliate; nuclear genome [1C] 7.6-10 pg [mode]; chloroplast long single copy ca 30kb inversion [from psbM to ycf2]; mitochondrion with loss of 4 genes, absence of numerous group II introns; LITTLE ZIPPER proteins.
LIGNOPHYTA†
Sporophyte woody; stem branching axillary, buds exogenous; lateral root origin from the pericycle; cork cambium + [producing cork abaxially], vascular cambium bifacial [producing phloem abaxially and xylem adaxially].
SEED PLANTS† / SPERMATOPHYTA†
Growth of plant bipolar [plumule/stem and radicle/root independent, roots positively geotropic]; plants heterosporous; megasporangium surrounded by cupule [i.e. = unitegmic ovule, cupule = integument]; pollen lands on ovule; megaspore germination endosporic, female gametophyte initially retained on the plant, free-nuclear/syncytial to start with, walls then coming to surround the individual nuclei, process proceeding centripetally.
EXTANT SEED PLANTS
Plant evergreen; nicotinic acid metabolised to trigonelline, (cyanogenesis via tyrosine pathway); microbial terpene synthase-like genes 0; primary cell walls rich in xyloglucans and/or glucomannans, 25-30% pectin [Type I walls]; lignin chains started by monolignol dimerization [resinols common], particularly with guaiacyl and p-hydroxyphenyl [G + H] units [sinapyl units uncommon, no Maüle reaction]; roots often ≥1 mm across, stele diarch to pentarch, xylem and phloem originating on alternating radii, cork cambium deep seated, gravitropism response fast; stem apical meristem complex [with quiescent centre, etc.], plasmodesma density in SAM 1.6-6.2[mean]/μm2 [interface-specific plasmodesmatal network]; eustele +, protoxylem endarch, endodermis 0; 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 +; cork cambium superficial; leaf nodes 1:1, a single trace leaving the vascular sympodium; leaf vascular bundles amphicribral; guard cells the only epidermal cells with chloroplasts, stomatal pore with active opening in response to leaf hydration, control by abscisic acid, metabolic regulation of water use efficiency, etc.; branching by axillary buds, exogenous; prophylls two, lateral; leaves with petiole and lamina, development basipetal, lamina simple; sporangia borne on sporophylls; spores not dormant; microsporophylls aggregated in indeterminate cones/strobili; grains monosulcate, aperture in ana- position [distal], primexine + [involved in exine pattern formation with deposition of sporopollenin from tapetum there], exine and intine homogeneous, exine alveolar/honeycomb; ovules with parietal tissue [= crassinucellate], megaspore tetrad linear, functional megaspore single, chalazal, sporopollenin 0; gametophyte ± wholly dependent on sporophyte, development initially endosporic [apical cell 0, rhizoids 0, etc.]; male gametophyte with tube developing from distal end of grain, male gametes two, developing after pollination, with cell walls; embryo cellular ab initio, suspensor short-minute, embryonic axis straight [shoot and root at opposite ends], primary root/radicle produces taproot [= allorhizic], cotyledons 2; embryo ± dormant; chloroplast ycf2 gene in inverted repeat, trans splicing of five mitochondrial group II introns, rpl6 gene absent; ??whole nuclear genome duplication [ζ/zeta duplication event], 2C genome size (0.71-)1.99(-5.49) pg, two copies of LEAFY gene, PHY gene duplications [three - [BP [A/N + C/O]] - copies], 5.8S and 5S rDNA in separate clusters.
IID. ANGIOSPERMAE / MAGNOLIOPHYTA
Lignans, O-methyl flavonols, dihydroflavonols, triterpenoid oleanane, apigenin and/or luteolin scattered, [cyanogenesis in ANA grade?], lignin also with syringyl units common [G + S lignin, positive Maüle reaction - syringyl:guaiacyl ratio more than 2-2.5:1], hemicelluloses as xyloglucans; root cap meristem closed (open); pith relatively inconspicuous, lateral roots initiated immediately to the side of [when diarch] or opposite xylem poles; epidermis probably originating from inner layer of root cap, trichoblasts [differentiated root hair-forming cells] 0, hypodermis suberised and with Casparian strip [= exodermis]; shoot apex with tunica-corpus construction, tunica 2-layered; starch grains simple; primary cell wall mostly with pectic polysaccharides, poor in mannans; tracheid:tracheid [end wall] plates with scalariform pitting, multiseriate rays +, wood parenchyma +; sieve tubes enucleate, sieve plates with pores (0.1-)0.5-10< µm across, cytoplasm with P-proteins, not occluding pores of plate, companion cell and sieve tube from same mother cell; ?phloem loading/sugar transport; nodes 1:?; dark reversal Pfr → Pr; protoplasm dessication tolerant [plant poikilohydric]; stomata randomly oriented, brachyparacytic [ends of subsidiary cells ± level with ends of guard cells], outer stomatal ledges producing vestibule, reduction in stomatal conductance with increasing CO2 concentration; lamina formed from the primordial leaf apex, margins toothed, development of venation acropetal, overall growth ± diffuse, secondary veins pinnate, fine venation hierarchical-reticulate, (1.7-)4.1(-5.7) mm/mm2, vein endings free; flowers perfect, pedicellate, ± haplomorphic, protogynous; parts free, numbers variable, development centripetal; P = T, petal-like, 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], each theca dehiscing longitudinally by a common slit, ± embedded in the filament, walls with at least outer secondary parietal cells dividing, endothecium +, 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 restricted to the apertural regions, thin, compact, intine in apertural areas thick, orbicules +, pollenkitt +; nectary 0; carpels present, superior, free, several, spiral, ascidiate [postgenital occlusion by secretion], stylulus at most short [shorter than ovary], hollow, cavity not lined by distinct epidermal layer, stigma ± decurrent, carinal, dry; suprastylar extragynoecial compitum +; 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, nucellar cap?; megasporocyte single, hypodermal, functional megaspore lacking cuticle; female gametophyte lacking chlorophyll, four-celled [one module, egg and polar nuclei sisters]; ovule not increasing in size between pollination and fertilization; pollen grains bicellular at dispersal, germinating in less than 3 hours, siphonogamy, pollen tube unbranched, growing towards the ovule, between cells, growth rate (ca 10-)80-20,000 µm h-1, tube apex of pectins, wall with callose, lumen 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 gametophytes tricellular, gametes 2, lacking cell walls, ciliae 0, double fertilization +, ovules aborting unless fertilized; fruit indehiscent, P deciduous; mature seed much larger than fertilized ovule, small [<5 mm long], dry [no sarcotesta], exotestal; endosperm +, ?diploid [one polar nucleus + male gamete], cellular, development heteropolar [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, embryo short [<¼ length of seed]; plastid and mitochondrial transmission maternal; Arabidopsis-type telomeres [(TTTAGGG)n]; nuclear genome [2C] (0.57-)1.45(-3.71) [1 pg = 109 base pairs], ??whole nuclear genome duplication [ε/epsilon event]; 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, palaeo AP3 and PI genes [paralogous B-class genes] +, with "DEAER" motif, SEP3/LOFSEP and three copies of the PHY gene, [PHYB [PHYA + PHYC]]; chloroplast IR expansions, chlB, -L, -N, trnP-GGG genes 0.
[NYMPHAEALES [AUSTROBAILEYALES [MONOCOTS [[CHLORANTHALES + MAGNOLIIDS] [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 [MONOCOTS [[CHLORANTHALES + MAGNOLIIDS] [CERATOPHYLLALES + EUDICOTS]]]]: phloem loading passive, via symplast, plasmodesmata numerous; vessel elements with scalariform perforation plates in primary xylem; essential oils in specialized cells [lamina and P ± pellucid-punctate]; tension wood + [reaction wood: with gelatinous fibres, G-fibres, on adaxial side of branch/stem junction]; anther wall with outer secondary parietal cell layer dividing; tectum reticulate; nucellar cap + [character lost where in eudicots?]; 12BP [4 amino acids] deletion in P1 gene.
[MONOCOTS [[CHLORANTHALES + MAGNOLIIDS] [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 [?here]; pollen tube growth intra-gynoecial; extragynoecial compitum 0; carpels plicate [?here]; embryo sac monosporic [spore chalazal], 8-celled, bipolar [Polygonum type], antipodal cells persisting; endosperm triploid.
[CERATOPHYLLALES + EUDICOTS]: ethereal oils 0 [or next node up]; fruit dry [very labile].
EUDICOTS: (Myricetin +), asarone 0 [unknown in some groups, + in some asterids]; root epidermis derived from root cap [?Buxaceae, etc.]; (vessel elements with simple perforation plates in primary xylem); nodes 3:3; stomata anomocytic; flowers (dimerous), cyclic; protandry common; K/outer P members with three traces, ("C" +, with a single trace); A ?, 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], short [<2 x length of ovary]; seed coat?; palaeotetraploidy event.
[PROTEALES [TROCHODENDRALES [BUXALES + CORE EUDICOTS]]]: (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]: mitochondrial rps11 gene lost.
CORE EUDICOTS / GUNNERIDAE: (ellagic and gallic acids +); leaf margins serrate; compitum + [one position]; micropyle?; γ genome duplication [allopolyploidy, 4x x 2x], x = 3 x 7 = 21, 2C genome size (0.79-)1.05(-1.41) pg, PI-dB motif +; small deletion in the 18S ribosomal DNA common.
[ROSIDS ET AL. + ASTERIDS ET AL.] / PENTAPETALAE / [SANTALALES, CARYOPHYLLALES, SAXIFRAGALES, DILLENIALES, VITALES, ROSIDAE, [BERBERIDOPSIDALES + ASTERIDAE]: root apical meristem closed; (cyanogenesis also via [iso]leucine, valine and phenylalanine pathways); flowers rather stereotyped: 5-merous, parts whorled; P = K + C, K enclosing the flower in bud, with three or more traces, odd K adaxial, C with single trace; A = 2x K/C, in two whorls, alternating, (many, but then usually fasciculate and/or centrifugal); pollen tricolporate; G [(3, 4) 5], when 5 opposite K, whorled, placentation axile, style +, stigma not decurrent, compitum + [one position]; endosperm nuclear/coenocytic; fruit dry, dehiscent, loculicidal [when a capsule]; floral nectaries with CRABSCLAW expression, RNase-based gametophytic incompatibility system present.
Phylogeny. Prior to the seventh version of this site asterids were part of a major polytomy that included rosids, Berberidopsidales, Santalales, and Caryophyllales, but then the order of branching below the asterids seemed to be stabilizing, perhaps with a clade [Berberidopsidales [Santalales [Caryophyllales + Asterids]]] while rosid relationships seemed to be [Saxifragales [Vitales + Rosids]]]. However, recent work suggests a polytomy is indeed probably the best way to visualize relationships around here at present. So for further discussion of relationships at the base of asterids and rosids, see the Pentapetalae node.
[BERBERIDOPSIDALES + ASTERIDAE]: ?
ASTERIDAE / ASTERANAE Takhtajan: nicotinic acid metabolised to its arabinosides; (iridoids +); tension wood decidedly uncommon; C enclosing A and G in bud, (connate [sometimes evident only early in development, petals then appearing to be free]); anthers dorsifixed?; if nectary +, gynoecial; G [2], style single, long; ovules unitegmic, integument thick [5-8 cells across], endothelium +, nucellar epidermis does not persist; exotestal [!: even when a single integument] cells lignified, esp. on anticlinal and/or inner periclinal walls; endosperm cellular.
[ONCOTHECALES [LAMIIDAE/ASTERID I + CAMPANULIDAE/ASTERID II]] / CORE ASTERIDS / EUASTERIDS / GENTIANIDAE: plants woody, evergreen; ellagic acid 0, non-hydrolysable tannins not common; vessel elements long, with scalariform perforation plates; sugar transport in phloem active; inflorescence usu. basically cymose; flowers rather small [<8 mm across]; C free or basally connate, valvate, often with median adaxial ridge and inflexed apex ["hooded"]; A = and opposite K/P, free to basally adnate to C; G [#?]; ovules 2/carpel, apical, pendulous; fruit a drupe, [stone ± flattened, surface ornamented]; seed single; duplication of the PI gene.
ASTERID II / CAMPANULIDAE / [METTENIUSALES [BRUNIALES [ASTERALES [APIALES, DESFONTAINIALES, DIPSACALES, ESCALLONIALES, PARACRYPHIALES]]]]: myricetin 0; style shorter than the ovary; endosperm copious, embryo short/very short.
[BRUNIALES [ASTERALES [APIALES, DESFONTAINIALES, DIPSACALES, ESCALLONIALES, PARACRYPHIALES]]] / APIIDAE: tube initiation early; G inferior, [2], style long.
[ASTERALES [APIALES, DESFONTAINIALES, DIPSACALES, ESCALLONIALES, PARACRYPHIALES]] / CORE CAMPANULIDS: C forming distinct tube; A epipetalous.
[APIALES, DESFONTAINIALES, DIPSACALES, ESCALLONIALES, PARACRYPHIALES]: ?
If the next two are clades...[APIALES [PARACRYPHIALES + DIPSACALES]] / DIPSAPIIDAE: nodes 3:3.
[PARACRYPHIALES + DIPSACALES] / DIPSIDAE: true tracheids +; lamina margin serrate; inflorescence terminal.
Age. K. Bremer et al. (2004) suggested an age of about 111 Ma for this node, Magallón et al. (2015) an age of ca 81.8 Ma, and Wikström et al. (2015) an age of (104-)92(-79) My; around 94.2 Ma is the estimate in Tank et al. (2015: Table S2) and (101.4-)86.6(-71.8) Ma in Tank and Olmstead (2017).
Evolution: Divergence & Distribution. Diversification here probably occurred in the southern hemisphere (Beaulieu et al. 2013a).
Dipsacales, with some 1130 species, are far more diverse than Paracryphiales - the latter include a mere 38 or so species.
PARACRYPHIALES Reveal - Main Tree.
Just the one family, 3 genera, 38 species.
Note: In all node characterizations, boldface denotes a possible apomorphy, (....) denotes a feature the exact status of which in the clade is uncertain, [....] includes explanatory material; other text lists features found pretty much throughout the clade. Note that the precise node to which many characters, particularly the more cryptic ones, should be assigned is unclear. This is partly because homoplasy is very common, in addition, basic information for all too many characters 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 are the not-so-trivial issues of how character states are delimited and ancestral states are reconstructed (see above).
Phylogeny. For the relationships of Paracryphiales, see the asterid II/gentianid clade.
Includes Paracryphiaceae.
Synonymy: Sphenostemonineae I. Savin. - Quintiniales Doweld, Sphenostemonales Doweld
PARACRYPHIACEAE Airy-Shaw - Back to Paracryphiales
Trees or shrubs, evergreen; vessel elements with highly scalariform perforation plates [>48 bars/plate - mean no.]; nodes 3:3; leaves spiral, lamina margins serrate; inflorescences terminal, racemose; flowers 4-merous; P or K + C free; A not adnate to P/C, anther thecae ± embedded in connective/basifixed; G position?; fruit septicidal capsule.
3 [list]/38 - as genera below. Southwest Pacific: Philippines to New Zealand and New Caledonia.
Age. K. Bremer et al. (2004) suggested an age of about 101 Ma and Wikström et al. (2015) an age of (98-)78(-32) Ma for crown-group Paracryphiaceae.
Evolution: Divergence & Distribution. The three genera included in Paracryphiales are quite different florally and are also rather unlike other campanulids. Quintinia is reported to have ellagic acid (along with iridoids!), and it and fossils that have been associated with it may even have bitegmic ovules (Friis & Pedersen 2012). Sphenostemon and Paracryphia sometimes have more than twice as many stamens as perianth parts; the apomorphies of Paracryphia in particular represent a very odd combination for an gentianid.
The Late Cretaceous Silvianthemum suecicum, from rocks in southern Sweden, has several exquisitely-preserved features - perhaps most notably the radial stylar cells - suggesting a relationship with Quintinia in particular (Friis 1990). Martínez-Millán (2010: 83.5 My) recovered this relationship in a phylogenetic analysis of possibly related campanulids, although no other Paracryphiales were included, and she thought better knowledge of Escalloniales might help place the fossil more securely (see also Friis et al. 2011, 2013b). However, Silvianthemum has tricolp(or)ate pollen, there are eight stamens (c.f. Friis et al. 2011: the perianth is 5-merous), the anthers appear to be dorsifixed (a synapomorphy with Quintinia - Martínez-Millán 2010), there are three short, adaxially grooved styles (c.f. Quintinia), and three stipitate parietal placentae. Bertilanthus scanicus, from the same rocks, has a very similar set of characters, and, like Quintinia, it has glandular hairs, but it also has stamens opposite the petals, a feature at most vanishingly infrequent in the campanulids, and differs in other respects from Quintinia (Friis & Pedersen 2012). However, the androecium in extant Paracryphiales is variable. The ovules of Bertilanthus may be bitegmic ("ovary wall [sic] split in two": Friis & Pedersen 2012: p. 326), which would be in line with reports for Quintinia. However, recent studies suggest a position for Bertilanthus in Saxifragales (López-Martínez et al. 2023a: Fig. 2D).
If the relationships of these fossils hold, then the current distribution of Paracryphiales has little to do with their past distribution. However, a position of the fossils within Cornales was suggested by Beaulieu et al. (2013a), which agrees better with their morphology (and geography). Moreover, Friis et al. (2013b) are inclined to question the position of Quintinia itself in the campanulids. Altogether, Paracryphiales are something of a conundrum.
1. Quintinia A. de Candolle —— Synonymy: Quintiniaceae Doweld
Plants Al accumulators, group 1 secoiridoids, ellagic acid +; pits vestured; (nodes 5:5); petiole bundle?; peltate glands + [cells of head radiating]; buds naked; (plant dioecious: New Caledonia), inflorescences branched or not; flowers often 5-merous; K not protecting bud, sepals with 1 trace, aestivation open; pollen 4-6 colporate; G [3-5], inferior, placentation ± parietal, nectary on top of ovary, style longish, postgenitally connate, stout, with prominent radiating cells, stigmas expanded, wet; ovules 3-many/carpel, ?bitegmic, micropyle endostomal, parietal tissue absent; fruit K persistent; seeds somewhat flattened, shortly winged?; micropylar endosperm haustorium?; n = 22.
1/25. The Philippines, Sulawesi and New Guinea to New Zealand and New Caledonia. Map: from Heywood (2007, in part).
[Paracryphia + Sphenostemon]: styloids +; hairs unicellular; buds perulate; K/P decussate; nectary 0; style 0.
2. Paracryphia alticola Baker f.
Chemistry?; petiole bundle flattened-annular, with medullary bundles; hairs dense; plant andromonoecious; inflorescence (branched); flowers sessile; P (5), decussate-cochleate, caducous; A 8(-15), filaments filiform; G [8-15], stigmas central, separate, conduplicate; [staminate flowers: A 4 or more, filaments stout; G 0]; ovules 4/carpel, integument ca 4 cells across, parietal tissue 1-2 cells across; carpels eventually pulling away acropetally and opening adaxially, columella persistent; seeds winged, exotesta with sinuous anticlinal walls, inner walls lignified; embryo smallish, radicle relatively long; n = ?
1/1. New Caledonia.
3. Sphenostemon Baillon —— Synonymy: Sphenostemonaceae P. van Royen
Iridoids?; phloem stratified; sort resiniferous ducts; (styloids +); petiole bundles three, arcuate, or verically-flattened incurved C-shaped, or annular with wing bundles; leaves (opposite), stipules cauline, minute; inflorescences (axillary), unbranched; P (2), 4 + 4, decussate; A = and opposite P, -12 [when P 0], connective massive, filaments much shorter than anthers; pollen 3-/4-por(or)ate (inaperturate); G [2], placentation apical, stigma large, capitate [2 separate stigmas]; ovules 1(2)/carpel, apotropous, "crassinucellate", endothelium?, funicle massive, papillate [?= obturator]; fruit a berry; seeds 1 (2), ruminate or not, exo- or exoendotestal, testa sclerenchymatous [Carlquist], endotestal cells with dark contents; embryo short?; n = ca 26.
1/10. New Guinea, Australia (Queensland) and New Caledonia. Map: from van Balgooy (1984) and Mark Newman (pers. comm.).
Evolution: Divergence & Distribution. For more on the inferior/superior ovary distinction in the campanulids, see the Escalloniales page. The vessel elements of the three genera are very long and the perforation plates have many bars (up to 159 - mean number/plate - Paracryphia), indeed, aspects of the wood anatomy of Paracryphia have been considered to be among the most primitive in angiosperms. Carlquist (2018b, see also Olson 2020) was at pains to point out the possible adaptive significance of these and other anatomical features of the three genera, the former also suggested apomorphies for them.
All three genera are rather poorly known - Sphenostemon particularly so - and need an exhaustive comparative study; this should be accompanied by a reworking of their molecular relationships.
Chemistry, Morphology, etc.. The considerable variation in petiole anatomy in Sphenostemon may depend where in the petiole the transverse sections were taken. Styloids are visible on the abaxial surface of the lamina of Papuasian species of Sphenostemon; they look rather like cystoliths.
Pillon and Hequet (2019) found that nearly all specimens of Quintinia from New Caledonia had flowers of only one type, i.e., the plants were dioecious. The placentation of Quintinia is basically parietal (Bensel & Palser 1975b; see also Friis et al. 2103b); the ovules may be bitegmic and crassinucellate (Mauritzon 1933; Philipson 1974; Friis et al. 2013b). For some details of the flower of Sphenostemon, see Endress (2008c). Its fruit is often described as being a drupe, but Lundberg (2001c) characterized it as being a pseudo-drupe (and the seeds as being pachychalazal), while Savinov (2003) described it as being a berry. The nature of the perianth in both Paracryphia and Sphenostemon needs attention. In the former, it is almost as if the bract encloses the sessile flower, while in the latter the first perianth members are lateral and subpeltate.
For Paracryphia, see Swamy (1953b), Lundberg (2001e) and Dickison and Lundberg (2016), all general, and Dickison and Baas (1977) and Carlquist (2012c), both wood anatomy. For Quintinia, see Lundberg (2000d) and Dickison and Lundberg (2016), both general. For Sphenostemon, see Bailey and Swamy (1953), Jéremie (1997) and Thiv (2016) for general information, Carlquist (2012c) for wood anatomy, and Savinov (2003) for fruit and seed anatomy.
Phylogeny. Relationships are [Quintinia [Paracryphia + Sphenostemon]] (Tank & Donoghue 2009). However, note that Polyosma (Escalloniales) linked with Quintinia in an analysis of mitochondrial genes, but not of other genes; this is probably because of horizontal transfer of the mitochondrial genome from Quintinia to Polyosma (Soltis et al. 2011).
Classification. The three genera have all been placed in monogeneric families, but only relatively recently; they are combined here (see also A.P.G. 2009, 2016).
Thanks. Thanks to Y. Pillon for comments.
Previous Relationships. Just about everywhere. Paracryphiaceae were included in Theales by Cronquist (1981) and in Theanae by Takhtajan (1997). Quintinia has long been included in woody Saxifragaceae/Hydrangeaceae. Baas (1975) thought that Sphenostomonaceae were members of Celastrales, close to Icacinaceae (sic); Cronquist (1981) had placed them in Aquifoliaceae, next to Icacinaceae, while Takhtajan (1997) included them in Icacinales. Sphenostemon (as Idenburgia) has also been placed in Trimeniaceae.