EXTANT SEED PLANTS

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 rich in guaiacyl units; true roots present, apex multicellular, xylem exarch, branching endogenous; arbuscular mycorrhizae +; shoot apical meristem multicellular, interface specific plasmodesmatal network; stem with ectophloic eustele, endodermis 0, xylem endarch, branching exogenous; vascular tissue in t.s. discontinuous by interfascicular regions; vascular cambium + [xylem ("wood") differentiating internally, phloem externally]; wood homoxylous, tracheids +; tracheid/tracheid pits circular, bordered; sieve tube/cell plastids with starch grains; phloem fibers +; stem cork cambium superficial, root cork cambium deep seated; nodes ?; stomata ?; leaf vascular bundles collateral; leaves spiral, simple, axillary buds?, prophylls [including bracteoles] two, lateral, veins -5 mm/mm² [mean for all non-angiosperms 1.8]; plant heterosporous, sporangia eusporangiate, on sporophylls, sporophylls aggregated in indeterminate cones/strobili; true pollen [microspores, i.e. no distal pore for release of gametes] +, grains mono[ana]sulcate, exine and intine homogeneous, ovules unitegmic, crassinucellate, 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, with cell walls, with many flagellae; female gametophyte endosporic, initially syncytial, walls then surrounding individual nuclei; seeds "large", first cell wall of zygote transverse, embryo straight, endoscopic [suspensor +], short-minute, with morphological dormancy, white, cotyledons 2; plastid transmission maternal; two copies of LEAFY gene, PHY gene duplication [N/O//A/C and P//BE lines], mitochondrial nad1 intron 2 and coxIIi3 intron present.

MAGNOLIOPHYTA

Plant woody, evergreen; lignans, O-methyl flavonols, dihydroflavonols, triterpenoid oleanane, non-hydrolysable tannins, quercetin and/or kaempferol +, apigenin and/or luteolin scattered, [cyanogenesis in ANITA grade?], lignins derived from both coniferyl and sinapyl alcohols, containing syringaldehyde [in positive Maüle reaction, syringyl:guaiacyl ratio less 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; stem with 2-layered tunica-corpus construction; wood fibers and wood parenchyma +; reaction wood ?, with gelatinous fibres; starch grains simple; primary cell wall mostly with pectic polysaccharides; tracheids +; sieve tubes eunucleate, with a sieve plate and cytoplasm with P-proteins, companion cells from same mother cell that gave rise to the sieve tube; nodes unilacunar [1:?]; stomata with ends of guard cells level with pore, paracytic, outer stomatal ledges producing vestibule; leaves with petiole and lamina [the latter formed from the primordial leaf apex], development of venation acropetal, 2ndary veins pinnate, fine venation reticulate, veins (1.7-)4.1(-5.7) mm/mm², endings free; flowers perfect, polysymmetric, parts spiral [esp. the A], free, development in general centripetal, numbers unstable; P not sharply differentiated, outer members not enclosing the rest of the bud, smaller than inner members; A many, with a single trace, introrse, filaments stout, anther ± embedded in the filament, tetrasporangiate, dithecal, with at least outer secondary parietal cells dividing, each theca dehiscing longitudinally by action of hypodermal endothecium, endothecial cells elongated at right angles to long axis of anther; tapetum glandular, binucleate; microspore mother cells in a block, microsporogenesis successive, walls developing by centripetal furrowing; pollen subspherical, binucleate at dispersal, trinucleate eventually, tectum continuous or microperforate, ektexine columellar, endexine thin, compact, lamellate only in the apertural regions, pollen germinating in less than 3 hours, tube elongated, growing at 80-600 µm/hour, with callose plugs and callose-based walls, penetrating between cells, siphonogamy, penetration of ovules within ca 18 hours , nectary 0, G free, several, ascidiate, with postgenital occlusion by secretion, few [?1] ovules/carpel, ovules marginal, anatropous, bitegmic, [outer integument often largely subdermal in origin, inner integument dermal], micropyle endostomal, integuments 2-3 cells thick, megasporocyte single, megaspore lacking sporopollenin and cuticle, chalazal, female gametophyte four-celled [one-modular, nucleus of egg cell sister to one of the polar nuclei], stylulus short, hollow, stigma ± decurrent, dry [not secretory]; P deciduous in fruit; seed exotestal; double fertilisation +, endosperm diploid, cellular [first division oblique, micropylar end initially with a single large cell, chalazal end more actively dividing], copious, oily and/or proteinaceous, embryo cellular ab initio, minute; germination hypogeal, seedlings/young plants sympodial; Arabidopsis-type telomeres [(TTTAGGG)_n]; whole genome duplication, 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 PHYA + C/PHYB + E gene pairs.

Evolution. Possible apomorphies for flowering plants are in bold. Note that the actual level to which many of these features, particularly the more cryptic ones, should be assigned is unclear, because some taxa basal to the [magnoliid + monocot + eudicot] group have been surprisingly little studied, there is considerable variation between families in particular for several of these characters, and also because details of relationships among gymnosperms will affect the level at which some of these characters are pegged. For example, if reticulate-perforate pollen is optimized to the next node on the tree (see Friis et al. 2009 for a discussion), it effectively makes the pollen morphology of the common ancestor of all angiosperms ambiguous....

NYMPHAEALES [AUSTROBAILEYALES [[CHLORANTHALES + MAGNOLIIDS] [MONOCOTS [CERATOPHYLLALES + EUDICOTS]]]]: vessels +, elements with scalariform perforation plates, axial parenchyma diffuse or diffuse-in-aggregate; tectum reticulate-perforate [here?]; ?genome duplication; "DEAER" motif in AP3 and PI genes lost, gaps in these genes.

ERICALES [ASTERID I + II]:ovules tenuinucellate.

ASTERID I + II: ellagic acid 0, proanthocyanidins not common; inflorescence cymose; C forming a distinct tube; A epipetalous, = and opposite sepals or P [polyandry (secondary) very uncommon indeed].

ASTERID II: Myricetin 0; vessel elements with scalariform perforation plates; flowers rather small, style short; endosperm copious, embryo short/very short.

ASTERALES [ESCALLONIALES [BRUNIALES [APIALES [PARACRYPHIALES + DIPSACALES]]]]: iridoids +; inflorescence?; C tube initiation early; G [2-3], inferior.

ESCALLONIALES [BRUNIALES [APIALES [PARACRYPHIALES + DIPSACALES]]]: ?

BRUNIALES [APIALES [PARACRYPHIALES + DIPSACALES]]: ?

APIALES [PARACRYPHIALES + DIPSACALES]: ?

PARACRYPHIALES + DIPSACALES: nodes 3:3; true tracheids +; leaves serrate; inflorescence terminal.

PARACRYPHIALES Reveal  Main Tree, Synapomorphies.

Inflorescence racemose; flowers 4-merous, filaments stout, thecae ± embedded in connective; G position?; capsule septicidal. - 1 family, 3 genera, 36 species.

Phylogeny. For the placement of Paracryphiaceae/Paracryphiales, see Winkworth et al. (2008) and Tank and Donoghue (2009).

Previous Relationships. Various families have been placed here or elsewhere in the asterid II clade, but with uncertain support; recent work is clarifying their relationships (Winkworth et al. 2008a; Tank & Donoghue 2009). For Polyosmaceae and Escalloniaceae, here as Escalloniaceae, see Escalloniales; Paracryphiaceae, Quintiniaceae, and Sphenostemonaceae are combined as Paracryphiaceae and are dealt with below; while Columelliaceae and Desfontainiaceae (as Columelliaceae) are close Bruniaceae, together making up Bruniales.

Includes Paracryphiaceae.

Synonymy: Sphenostemonineae I. Savin. - Quintiniales Doweld, Sphenostemonales Doweld

PARACRYPHIACEAE Airy-Shaw   Back to Paracryphiales

Leaves spiral.

3 [list]/36 - three genera below. S.W. Pacific, Philippines to Australia and New Caledonia.

1. Paracryphia Baker f.

Woody; chemistry?; petiole bundle flattened-annular, with medullary bundles; styloids +; hairs unicellular; inflorescence branched-spicate, plant andromonoecious; P (5), decussate-cochleate, caducous; A 8(-11), nectary 0, G [8-15], attached to central axial tissue, 4 crassinucellate ovules/carpel, stigmas central, separate, conduplicate; fruit with carpels pulling away acropetally and opening adaxially, columella persistent; seeds winged, exotesta? with sinuous anticlinal walls, inner walls lignified; embryo size?, radicle relatively long; n = ?

1/1: Paracryphia alticola. New Caledonia.

2. Quintinia A. de Candolle

Trees; plants Al accumulators, group 1 secoiridoids, ellagic acid +; vessels vestured; petiole bundle?; glands peltate; (leaf margins entire); flowers also 5-merous, C free, filaments less stout, anthers ± basifixed, placentoid ?, pollen 4-6 colporate; G [3-5], inferior, nectary +, placentation parietal or axile, many bitegmic ovules/carpel, micropyle endostomal, style long, stigma lobed, wet; K persistent; micropylar haustoria ?; n = ?22.

1/25. Philippines and New Guinea to New Zealand and New Caledonia (map: from Heywood 2007, in part).

3. Sphenostemon Baillon

Evergreen shrubs or trees; iridoids?; phloem stratified; petiole bundles three, arcuate, or annular with wing bundles; styloids + or 0; hairs unicellular; leaves (subopposite), margins toothed (entire), stipules cauline, minute; K and C decussate, free, or C 0, stamens = and opposite sepals-12, pollen por(or)ate; G [2], 1(2) pendulous ovule/carpel, funicular obturator +, endothelium?, style 0, stigma large, capitate; fruit a berry; seeds ruminate or not, exo- or exoendotestal, endotestal cells with dark contents; embryo short?; n = ?

1[list]/10. New Guinea, Australia (Queensland) and New Caledonia (map: from van Balgooy 1984; Mark Newman, pers. comm.).

• Quintinia is an evergreen tree or shrub with spiral, serrate, estipulate leaves; the plant is covered with peltate scales. The inflorescence is terminal and the flowers have free sepals and petals and an inferior ovary. The fruit is a septicidal capsule.

• Sphenostemon is usually a small, evergreen tree with spiral, strongly serrate leaves that lack stiples, and terminal inflorescences with rather small flowers. The sepals and petals are free, the anther thecae are borne on stout filaments, and there is no style; the fruit is fleshy and two-seeded.

Evolution. The Late Cretaceous Silvianthemum suecicum from Sweden, has many features suggesting a relationships with Quintinia (Friis 1990). However, it has tricolp(or)ate pollen, the anthers appear to be dorsifixed and there are three short, adaxially grooved styles.

Sphenostemon and Paracryphia are two of the few asterid I + II taxa which sometimes have more than twice as many stamens as petals; the perianth is either uniseriate and/or decussate. The apomorphies of Paracryphia in particular represent a very odd combination for a member of the asterid I + II clade.

Chemistry, Morphology, etc. Quintinia is almost unknown embryologically. Its placentation is perhaps fundamentally parietal (Bensel & Palser 1975b); the ovules may be bitegmic (Mauritzon 1933; Philipson 1974), but this needs confirming. Spenostemon, too, is poorly known. Styloids are visible on the abaxial surface of the lamina of Papuasian species; they look rather like cystoliths. For some details of the flower, see Endress (2008c). The 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.

For Paracryphia, see Dickison and Baas (1977: anatomy) and Lundberg (2001e: general); for Quintinia, see Lundberg (2000d: general); and for Sphenostemon, see Jéremie (1997) for general information, Savinov (2003) for fruit and seed anatomy.

Phylogeny. Paracryphiaceae form a clade in Lundberg's three-gene Bayesian analysis (Lundberg 2001e); Cameron (2001, see also 2003) also suggested an association between Paracryphia and Sphenostemon. The vessel elements of the three are very long and the perforation plates have many bars (aspects of the wood anatomy of Paracryphia have previously been considered to be among the most primitive in angiosperms...).

Classification. Since the three genera are morphologically rather different they are characterised separately above. They have all been placed in monogeneric families, but only relatively recently; they are combined here (see also APG 2009).

Previous Relationships. Paracryphia was included in Theales by Cronquist (1981) and in Theanae by Takhtajan (1997) as a monotypic family. It was linked quite strongly with Rutaceae + Meliaceae + Simaroubaceae by Källersjö et al. (1998), but cf. Savolainen et al. (2000a). Quintinia has long been included in woody Saxifragaceae/Hydrangeaceae. Baas (1975) thought that Sphenostomonaceae (and Phellinaceae) were members of Celastrales, close to Icacinaceae, while Takhtajan (1997) included them in Icacinales.

Synonymy: Quintiniaceae Doweld, Sphenostemonaceae P. van Royen