LIGNOPHYTA

True roots +; lateral meristems: cork cambium producing cork abaxially, vascular cambium producing phloem abaxially and xylem adaxially.

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, (lignins derived from p-coumaryl alcohol, i.e. S [syringyl] lignin units); true roots present, apex multicellular, xylem exarch, and 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 and rays alone, tracheid/tracheid pits circular, bordered; mature sieve tube/cell lacking functioning nucleus, plastids with starch grains; phloem fibres +; stem cork cambium superficial, root cork cambium deep seated; leaves with single trace from sympodium ["nodes 1:1"]; stomata ?; leaf vascular bundles collateral; leaves megaphyllous [determinancy evolved first, then ad/abaxial symmetry], spiral, simple, lamina with vein density up to 5 mm/mm² [mean for all non-angiosperms 1.8]; axillary buds associated with at most some leaves; prophylls [including bracteoles] two, lateral; 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, developing after pollination, 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 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; shoot apex with tunica-corpus construction, tunica 2-layered; reaction wood ?, with gelatinous fibres; 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 cells from same mother cell that gave rise to the sieve tube; sugar transport in phloem passive; nodes unilacunar [1:?]; stomata with ends of guard cells level with pore, paracytic, outer stomatal ledges producing vestibule; leaves petiolate, lamina [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; most/all leaves with axillary buds; flowers perfect, pedicellate, polysymmetric, 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 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, tectum continuous or microperforate, ektexine columellar, endexine thin, compact, lamellate only in the apertural regions; nectary 0; G 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]; P deciduous in fruit; seed exotestal; pollen binucleate at dispersal, trinucleate eventually, germinating in less than 3 hours, pollination siphonogamous, tube elongated, growing at 80-600 µm/hour, with pectic outer wall, callose inner wall and callose plugs, growing between cells, penetration of ovules via micropyle [porogamous] within ca 18 hours, distance to first ovule 1.1.-2.1 mm, tube moves between nucellar cells; double fertilisation +, endosperm diploid, cellular [micropylar and chalazal domains develop diffently, 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 cellular ab initio, minute; 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]].

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. This is because some taxa basal to the [magnoliid + monocot + eudicot] group have been surprisingly little studied, there is considerable homoplasy as well as variation within and between families of the ANITA grade 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... For other features such as details of sugar transport in the phloem, their placement on the tree is frankly speculative. Finally, for features such as parietal tissue/a nucellus only one (Nymphaeales) to three cells thick above the embryo sac and a stylar canal lacking an epidermal layer, although plesiomorphous for basal grade angiosperms (Williams 2009), I am unsure where on the tree a thicker nucellus and a stylar epidermal layer are acquired.

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

OXALIDALES Heintze  Main Tree, Synapomorphies.

Characters? - 7 families, 60 genera, 1815 species.

Evolution. Divergence & Distribution. The age of crown group Oxalidales was estimated as (74-)69, 62-(57) million years (two penalized likelihood dates), the stem group age being (109-)102, 91(-84) million years; Bayesian relaxed clock estimates were slightly older, to 112 million years (Wang et al. 2009). Wikström et al. (2001) suggested an age for stem Oxalidales of some (91-)88(-85) million years, and a crown group age of some (75-)72(-69) million years before present, while Magallón and Castillo (2009) estimated ages of ca 90.5 and 90.6 million years for relaxed and constrained penalized likelihood datings for the divergence of crown members, 101.9 and 102.1 million years (relaxed and constrained again) for the stem. Note that Huaceae were not included in any of these estimates. Finally, Wang et al. (2009: penalized likelihood dates) suggested that the same stem group originated 109-84 million years ago, while crown group divergence began 74-57 million years ago.

Chemistry, Morphology, etc. Leaves of Cunoniaceae and Elaeocarpaceae can be almost indistinguishable. Diplostemony does not occur in the order; the androecium of Cunoniaceae is obdiplostemonous, according to Huber (1963), and so agrees with that of Oxalidaceae (and Brunelliaceae [Orozco 2002] and Connaraceae). Connaraceae and Brunelliaceae have ovaries with adaxial furrows (cf. the ventral slit: Matthews & Endress 2002b). Is the distribution of taxa that have carpels with five vascular traces of any interest?

Some information is taken from Nandi et al. (1998). There is much information on floral morphology and development for the whole order in Matthews and Endress (2002b, summarized in 2006b, and with illustrations of fringed and lobed petals in Cunoniaceae and Elaeocarpaceae); Matthews and Endress (2002b) note the filaments are longer than the anthers in bud here (but not in Elaeocarpaceae), as in the unrelated Anisophylleaceae (Cucurbitales).

Phylogeny. A somewhat unexpected association of families. Molecular data suggest Oxalidaceae and Connaraceae in particular are close (Price & Palmer 1993; Williams et al. 1994; Fernando et al. 1995, etc.), and this position also has strong morphological support; the other families may form a clade sister to them (e.g. Zhang & Simmons 2006, Cephalotaceae not included; Soltis et al. 2011). For the relationships of Brunelliaceae, see Bradford and Barnes (2001), although morphological analyses (Miranda-Esquivel 2001; Orozco 2001a; Orozco Pardo 2002) suggest various groupings of Brunelliaceae and Cunoniaceae intermixed. The family pair [Brunelliaceae + Cephalotaceae] is suggested by Davis et al. (2004) and Crayn et al. (2006).

Zhang and Simmons (2006: see also Soltis et al. 2007a) found that Huaceae were sister to the other Oxalidales they examined, with quite strong support (jacknife values over 80%); they suggest that Huaceae should be included in Oxalidales. Zhu et al. (2007) found 76% (maximum parsimony) and 82% (maximum parsimony) bootstrap support for this position when the mitochondrial matR gene was examined, but support was lost when two chloroplast genes were added; support was only weak in the recent analysis of Wang et al. (2009) and Qiu et al. (2010), but moderate to strong in the multiple gene analysis of Soltis et al. (2011). All in all, however, Huaceae seem to be finding a more fixed place on the tree (see also Wurdack & Davis 2009), and movement is in order. However, they do do not seem to have even the rather unimpressive morphological features that characterize other Oxalidales.

Previous relationships. Although the flowers of Anisophyllea (Anisophylleaceae - Cucurbitales) are remarkably similar to those of Ceratopetalum (Matthews et al. 2001; cf. also Matthews & Endress 2004, 2006b), and there are perhaps comparable similarities in the fossil Platydiscus peltatus (Schönenberger et al. 2001a; see also Schönenberger & von Balthazar 2006), this is unlikely to reflect a close relationships between the two; Ceratopetalum is somewhat embedded in Cunoniaceae (see below) and the two families are in very different clades.

Includes Brunelliaceae, Connaraceae, Cephalotaceae, Cunoniaceae, Elaeocarpaceae, Huaceae, Oxalidaceae.

Synonymy: Bauerales Martius, Cephalotales Martius, Connarales Link, Cunoniales Martius, Elaeocarpales Berchtold & J. Presl, Huales Doweld, Tremandrales Martius

HUACEAE A. Chevalier

Evergreen, woody (lianes); ellagic acid?; hairs stellate or peltate (unequally 2-armed); cork?; cambium storying?; vessel elements with simple (scalariform) perforations; phloem with broad rays; cristarque cells +; petiole vasculature complex; stomata paracytic, cuticle waxes 0; leaves two-ranked, lamina margins entire, basal glands on margin or abaxial surface, (strong vein pair from the very base), stipules +; inflorescence axillary, fasciculate; (flowers 4-merous); K valvate or completely connate, C clawed or strongly obovate; A 2x C; pollen porate, nectary?; G [5], unilocular, placentation basal, style +, stigma punctate; ovules 1, (4-)6, micropyle?; fruit a ?septicidal capsule or drupe, pericarp with stony layer in middle; seed 1; testa (hairy - Hua) with vascular bundles, exotegmen of lignified palisade cells; endosperm copious, ?development, cotyledons flattened; n = ?

2[list]/3. Tropical Africa (map: from Heywood et al. 2007).

• Huaceae are evergreen plants, usually trees, that are recognizable by their two-ranked leaves the blades of which have a very fine, boxy reticulum; there are small glands at the very base of the lamina. The cauline stipules are early deciduous. The plant smells of garlic.

Chemistry, Morphology, etc. Poorly known, especially its chemistry and floral development/embryology. Hua has long-clawed petals with peltate blade, unremarkable anthers, a single ovule, and the fruit is a capsule; Afrostyrax has strongly obovate petals, aristate anthers dehiscing from the apex, and the fruit is a drupe. For additional information, see Baas (1972: anatomy) and Hegnauer (1989: a little chemistry).

Previous Relationships. The family has been of uncertain position in the past, being included in Malvales (e.g. Baas 1972; Takhtajan 1997), hardly unsurprisingly less out of place in the more heterogeneous Violales (Cronquist 1981), or left unplaced in the rosids by the A.P.G. I and II (1999, 2003).

[[Connaraceae + Oxalidaceae] [Cunoniaceae [Elaeocarpaceae [Brunelliaceae + Cephalotaceae]]]]: vessel element type?; mucilage cells +; stomata ?; leaves compound, odd-pinnate, tri-, or unifoliate; styles separate, stigma secretory; micropyle bistomal, integument multiplicative; endotesta crystalliferous and palisade, exotegmen also tracheidal.

Connaraceae + Oxalidaceae: plant construction sympodial; benzoquinone rapanone +, ellagic acid 0; roots diarch [lateral roots 4-ranked]; vessel elements with simple perforations; wood rays uniseriate; sieve tube plastids with protein crystalloids; calcium oxalate druses 0; cuticle wax platelets as rosettes; leaflets articulated, margins entire, 2ndary veins pinnate to palmate, stipules 0; flowers di- and tristylous; C postgenitally subbasally united, with uniseriate glandular hairs; nectary extrastaminal; A of two whorls of different lengths, connate basally, (5, with antepetalous A staminodial), with uniseriate glandular hairs; (pollen colpate); (stigma with rounded multicellular ornamentations); ovule with endothelium; K persistent in fruit; exotesta ± fleshy.

Chemistry, Morphology, etc. Sieve tube plastids may have protein crystalloids + starch [Connaraceae], crystalloids + fibres + starch [both], or crystalloids alone [Oxalis].

CONNARACEAE R. Brown, nom. cons.   Back to Oxalidales

Shrubs or lianes (trees); hairs uniseriate, submesifixed or not; wood commonly siliceous or with SiO₂ grains; (nodes 5:5, 7:7); stomata variable; leaves two-ranked or spiral, (unifoliate); (plants dioecious); (flowers 4-merous), pedicels articulated; (K connate; nectary 0; androgynophore +); A connate or not; G 1 (3) 5 (7, 8), (stipitate), placentation near-basal, stigmas capitate, ?type; ovules 2/carpel, collateral, [type?], funicle 0, outer integument 5-7 cells across, inner integument 3-5 cells across, micropyle exostomal, parietal tissue ca 1 cell across; fruit a follicle (also dehiscing abaxially; drupe), often only 1 G developing, sepals persistent, ± indurated; seed 1 (2); testa black, vascularized, sarcoexotesta ± developed, exotesta various, inc. palisade (lignified), tegmen multiplicative; endosperm 0 to abundant, oily; n = 14, 16.

12[list]/180: Connarus (80), Rourea (40-70). Pantropical, especially Africa and Old World (map: from Leenhouts 1958; Heywood 1978 [Africa]; Forero 1983). [Photo - Flower, Fruit.]

• Connaraceae are mostly woody lianes that twine in the apical parts of the innovations. They may be recognised by their pinnately compound, exstipulate leaves with transversely-ridged petioles, and ± ridged or keeled follicles with black and contrasting orange to red seeds. The follicles are usually single and swell to almost mature size well before the seeds are developed; the ripe seeds are partly squeezed out of the follicle. The small, radially symmetric flowers with stamens of two lengths are rather undistinguished.

Chemistry, Morphology, etc. The plants are often poisonous. Growth is rarely sylleptic (Keller 1994).

There are often five traces to each carpel. The ovules may be straight or anatropous. Number of nuclei in pollen? There is much useful information in Jongkind and Lemmens (1989) and Lemmens et al. (2004); Dickison (1971) described carpel anatomy.

Previous Relationships. The cuticle waxes of Connaraceae are similar to those of Fabaceae-Fabales (Ditsch & Barthlott 1994) with which Connaraceae have frequently been confused. However, the two are not particularly close, and can usually be distinguished because the Connaraceae lack stipules and have rather small, polysymmetric flowers with ten stamens of two different lengths, a combination of features unknown in Fabaceae.

Synonymy: Cnestidaceae Rafinesque

OXALIDACEAE R. Brown, nom. cons.   Back to Oxalidales

Trees to herbs (lianes); tannins +; petiole bundle(s) annular (with medullary bundles); mucilage cells?; juice acrid, soluble calcium oxalate accumulation; stomata paracytic; leaves spiral (two-ranked), (stipules +, small), colleters + [Oxalis]; inflorescence cymose; pedicels articulated; C contorted, often clawed; anthers extrorse; nectaries often glands opposite petals; G [(3-)5], stigmas spathulate/capitate; ovules (1-)2-many/carpel, (micropyle zig-zag; exostomal), outer integument 3-5 cells across, inner integument 3-5(-6) cells across, often tenuinucellate; (megaspore mother cells several), (embryo sac bisporic, 8-celled), antipodals degenerate; fruit a ± ribbed/angled capsule or berry; seed (arillate), (subruminate), (explosive); testa (not multiplicative), often mucilaginous, (endotesta walls thickened; not palisade), (exotegmen 2-layered), testa and tegmen less differentiated when fruit a berry, or tegmen 0 (Biophytum); endosperm +, starchy (0), embryo large, green or white [Oxalis]; n = (5-)7(-12).

6[list]/770: Oxalis (700), Biophytum (50). Usu. tropical or subtropical: species like Oxalis corniculata are very weedy and widespread (map: from Hultén 1958, 1971; Hultén & Fries 1986; Lourteig 2000 and references; GBIF Biophytum vii.2008; FloraBase vii.2008 - details of distribution uncertain especially in Africa). [Photo - Flower]

• Oxalidaceae may be recognised by their usually compound leaves with pulvinate leaflets; their leaflets are entire and often have subpalmate venation. The inflorescence is either cymose or has cymose branches, the flowers are heterostylous, the corolla is clawed, and soon withers or is deliquescent, the stamens are obviously of two lengths, and the styles have capitate stigmas. The fruit is often a more or less ribbed, loculicidal capsule.

Evolution. Divergence & Distribution. Oxalis in the Cape region is a major element of the geophytic flora there (Procheŝ et al. 2006). Of the some 200 species in southern Africa, about 180 grow in the Greater Cape floristic region. Diversification of Oxalis in the Fynbos began about (31-)15.75 million years ago, that in the succulent karoo some (20-)10 million years ago (Verboom et al. 2009). All have tunicate bulbs, some species having very distinctive methods of vegetative reproduction and perennation, and they show more vegetative than floral variation (Oberlander et al. 2009). African Oxalis has its origin in South America (Oberlander et al. 2011). Indeed, Oxalis is most diverse in South America, where they may be also be shrubs to vines; New World species that are bulbous have scaly bulbs, or fleshy scales are borne along a rhizome, and these scales may be equivalent to stipules or to whole leaves (Emshwiller et al. 2009). There are few other non-monocot bulbous taxa.

Floral Biology & Seed Dispersal. There has been parallel evolution of distyly from tristyly within the New World bulbous species, and distyly is particularly common in a North American clade (Gardner et al. 2012).

The mucilaginous testa is often mistaken for an aril; the turgor pressure that builds up in it forces the rest of the seed out explosively, rather like squeezing a grape pip.

Economic Importance. For Oxalis tuberosa (oca) and its relatives, see Emswhiller (2002).

Chemistry, Morphology, etc. Averrhoa is rather different from other members of the family. It has sieve tube plastids with protein crystalloids + fibres and starch, the ovules are weakly but definitely crassinucellate (but there is an endothelium) (Boesewinkel 1985b; Chung & Lim 1998), and the testa is multiplicative (Corner 1976). The leaves of Averrhoa carambola are two-ranked; the two species of the genus differ considerably in how they grow (Keller 1994).

The pollen of Oxalidaceae often contains starch. Link (1992a) describes the nectary glands as being opposite the calyx, but they are opposite the corolla at the bases of the filaments (e.g. Rama Devi 1991).

Some information is taken from Govindappa and Boriah (1956), Herr and Dowd (1968) and Narayana (1970), all embryology, etc., Robertson (1975: general) and Cocucci (2004: general); for cork position, see Averrhoa bilimbi.

Phylogeny. For relationships within some southern African Oxalis species, see Oberlander et al. (2004, especially 2011). The ca 210 African species of the genus, all bulbous and largely from the Cape region, form a clade with small, basal pectinations and then two major subclades (Oberlander et al. 2011). For a preliminary phylogeny of the genus as a whole, see Emshwiller et al. (2009).

Classification. The family is circumscribed more narrowly than in Cronquist (1981); Hypseocharis is placed in Geraniaceae; Lepidobotryaceae (Celastrales) and Dirachmaceae (Rosales) are separate families. See Lourteig (2000, and references) for extensive monographic work on Oxalis.

Synonymy: Averrhoaceae Hutchinson.

Cunoniaceae [Elaeocarpaceae [Brunelliaceae + Cephalotaceae]]: K valvate, postgenitally coherent by hairs; (antepetalous A shorter than the others).

CUNONIACEAE R. Brown, nom. cons.   Back to Oxalidales

Woody, branching from the current flush; plants often Al-accumulators; ellagic acid + or 0 [Bauera, Eucryphia]; wood with crystals; vessel elements with (simple to) mixed or scalariform perforation plates; sieve tubes with non-dispersive protein bodies; young stem with vascular cylinder; (nodes 1:3 [Bauera], 5:5; split laterals; etc.); petiole bundles (arcuate) annular (adaxial or medullary bundles +); stomata variable; leaves opposite, (palmate), leaflet margins gland-toothed, 2ndaries proceeding to the teeth, or not, (stipels +), stipule interpetiolar, rounded (acicular), (2, cauline-intrapetiolar - Lamanonia; 1, intrapetiolar), colleters +; flowers rather small, (4-)5(-10)-merous; C (0), ± = K in size (large); A 2 x K(-many, centripetal, with trunk bundles; = and opposite sepals [C - Spiraeanthemum]; obdiplostemonous), (anthers basifixed; not articulated), filaments often longer than the petals, incurved in bud; pollen dicolp(or)ate; nectary +; G (?1 - Hooglandia)[2 (3-)5(-many)] (free; inferior), opposite petals [?always], placentae intruding, styluli common, (style hollow), stigmas punctate to capitate or decurrent; ovules (1-)2-several/carpel, epitropous (apotropous), micropyle various, inc. zig-zag, obturator +; fruit a septicidal capsule, or follicle (drupe); exotestal and endotegmic cells tangentially elongated; endosperm (0), starchy (not Davidsonia); n = (12, 14-)16.

27[list]/280: Weinmannia (160), Pancheria (26). Largely temperate and tropical S. hemisphere, few African (map: from Good 1974). [Photo - Flower, Flower.]

• Cunoniaceae may be recognised by their opposite, usually odd-pinnately compound leaves with serrate leaflets and well-developed often intrapetiolar stipules. The flowers are often quite small and the filaments are notably longer than the petals. The fruit, when a capsule, is septicidal.

Evolution. Divergence & Distribution. Fossil flowers of Platydiscus peltatus from the Late Cretaceous of Sweden ca 85 million years ago seem assignable to this family (Schönenberger et al. 2001a; Friis et al. 2011); the stamens are no longer than the petals. Flowers from Burmese amber dated at 110-97 million years old (Tropidogyne: K 5, spreading, A 10, G [3], inferior, styluli spreading) look rather like those of Ceratopetalum (Chambers et al. 2010).

Chemistry, Morphology, etc. Several genera are distinctive. These include Davidsonia, which has myricetin, hairs urticating hair, spiral leaves with two large, lateral stipules. The small flowers lack petals, and the stamens, twice the number of sepals, alternate with nectariferous lobes. The gynoecium is bicarpellate and the placentation apical-axile with 5-7 pendulous ovules/carpel. The fruit is a schizocarpic drupe, the endocarp producing the "hairs". The 1-2 seeds are pachychalazal, vascularized, and lack endosperm. Eucryphia has flowers that have large petals, many stamens and 2-colpate pollen grains. The gynoecium has four-many carpels, and in fruit the carpels (valves) more or less separate and open internally; there is no coherent columella. Hooglandia has small stipules; the plant is dioecious, and the flowers lack a corolla and apparently have only a single carpel with two ovules; the fruit is a single-seeded drupe.

There are numerous lignified cells in the bark of Cunoniaceae. That Bauera has 1:3 nodes may be connected with the fact that it sometimes lacks stipules, however, there is considerable vegetative variation in the genus: When the leaves are trifoliate, there are no stipules; when the leaves are simple, the stipules are foliaceous. Both Eucryphia and Cunoniaceae s. str. have very small sieve tube plastids, those of the former have protein inclusions only and are about the smallest known (Behnke 1988b). The leaf teeth have a glandular apex: the lower branch of the main vein goes into the tooth, the other proceeds above it. Nodal anatomy is variable, as is stipule development; single interpetiolar stipules may be paired as primordia (Rutishauser & Dickison 1989). The flowers in an inflorescence often open almost simultaneously (Bradford & Barnes 2001) and sometimes centrifugally. The nectary varies in position from extrastaminal to intrastaminal. The pollen grains are typically very small. Cunonia has two oblique carpels (Engler 1930b). There are often five traces to each carpel. The endosperm is described as being oily by Cronquist (1981) and Mabberley (1997), but starchy by Hopkins and Hoogland (2002) and Bradford et al. (2004). It is not clear how common pachychalazal seeds are (see Doweld 1998a).

See also Jay (1968b) for chemistry, Dickison (1980a) for wood anatomy, Dickison (1980b) and Rutishauser and Dickison (1989) for nodal anatomy, Rutishauser and Dickison (1989) and Dickison and Rutishauser (1990) for stipules, Dickison (1975) for floral anatomy of Bauera, Hufford and Dickison (1992) for morphology, Gregory (1998) for general anatomy, Mathews et al. (2001) and Schönenberger et al. (2001a) for some floral morphology; Dickison (1989b) and Bradford et al. (2004) provide general information

Phylogeny. Morgan and Soltis (1993) early associated Baueraceae and Cunoniaceae. Note that morphological phylogenetic analyses of Cunoniaceae in the old sense, i.e. including Aphanopetalum (now Saxifragales), do not signal the latter out as being anything particularly distinctive... (Hufford & Dickinson 1992; Orozco Pardo 2002). In molecular analyses, Acsmithia + Spiraeanthemum form a clade sister to the rest of the family (Bradford & Barnes 2001). They have follicular fruits and vessel elements with scalariform perforation plates, but both features occur elsewhere in the family. Bradford (2002) discusses evolution in Cunonieae, while Sweeney et al. (2004) placed the distinctive and recently-discovered Hooglandia firmly in the family.

Synonymy: Baueraceae Lindley, Belangeraceae J. Agardh, Callicomaceae J. Agardh, Davidsoniaceae Bange, Eucryphiaceae Gay, nom. cons., Spiraeanthemaceae Doweld

Elaeocarpaceae [Brunelliaceae + Cephalotaceae] : inner integument 3-5 cells across.

ELAEOCARPACEAE Jussieu, nom. cons.   Back to Oxalidales

Trees or (ericoid) shrublets; pyrrolizidine and tropane alkaloids, etc., ellagic acid +; growth rings common; vessel elements in radial multiples and with simple (scalariform) perforations; fibres often septate; (nodes 1:1); petiole bundle annular, often with medullary (and flange) bundles; stomata anomo- para-, actino- or cyclocytic; leaves spiral or opposite (two-ranked), simple, lamina vernation variable, margins toothed (entire), 2ndary veins pinnate or palmate, stipules lateral (0; colleters +); inflorescence racemose or cymose or flowers axillary; flowers pendant, (4-merous), pedicels articulated (0); K (4-9), (connate), (± petal-like), C (0, 3-6), (aestivation cochlear, etc.), fringed/toothed (entire), with three traces; large nectary/androgynophore (0); A (1)2 x K-many, centrifugal, (± in groups opposite sepals), basifixed, filaments short, anthers tubular-porose or with short slits, (connective prolonged), with lignified hairs; G (1) [2-many], placenta position various, style +, (shortly divided), stigma ± punctate; ovules 1-many/carpel, (epitropous), ± hairy, (micropyle zig-zag), outer integument 2-6 cells across, inner integument 3-7(-17 - Tremandra et al.) cells across, (endothelium + - Tremandra et al.), (hypostase +), curved chalazal appendage +; fruit a (loculicidal + septicidal) capsule, spiny or not, or drupe (berry); when capsules, seeds hairy, with chalazal, raphal or integumentary aril, or apical chalazal strophiole, or not, testal cells ± elongated, thickened and lignified (sarcotesta +; endotesta not crystalliferous), tegmen with vascular bundles (endotegmen lignified); endosperm ± copious, oily, initially starchy [Tremandra, etc.], embryo green [1 record], (curved - Sericolea, some Elaeocarpus); n = 12, 14, 15, 21.

12[list]/605: Elaeocarpus (350), Sloanea (150), Tetratheca (50). Tropical, esp. Papuasia-Australia, not mainland Africa (map: from Vester 1940; van Balgooy 1993: for early Tertiary fosssils [green], see Manchester & Kvacek 2009). [Photo - Flower, Fruit.]

• Elaeocarpaceae are woody plants that can be recognised by their leaves that tend to turn red or orange red, sometimes yellow, as they die; the blades are often serrate and the petiole can be swollen at one or both ends. Terminalia branching is quite common. The moderate-sized, pendulous flowers are borne in often racemose inflorescences. Both calyx and corolla are often valvate, the petals, when present, are often fringed, there is often a very prominent disc that is usually outside the stamens, the basifixed anthers often have rather short filaments and dehisce by pores or short slits (these may elongate), and the fruit is either a drupe or berry or an often muricate capsule with arillate and/or hairy seeds.

Evolution. Divergence & Distribution. Stem group Elaeocarpaceae may be in the order of 66-64 million years old, whereas divergence of crown group members occurred 59-57 million years before present (Wikström et al. 2001). Crayn et al. (2006) suggest diversification within the family may have been underway over 100 million years before present, with divergence of the xeromorphic Tremandra et al. clade occurring some 64 million years before present, and diversification within it beginning some 37 million years before present. Fruits and leaves identified as Sloanea are known quite widely from the early Palaeocene (late Danian) onwards (Kvacek et al. 2001b), and the family may also occur in North America in the Late Cretaceous (Manchester & Kvacek 2009).

Genes & Genomes. Although there seems to have been elevated molecular divergence in the Tremandra et al. clade, it is distinctly less speciose than its sister clade, which includes Elaeocarpus, by far the largest genus in the family (Crayn et al. 2006).

Chemistry, Morphology, etc. The corolla is more or less (induplicate-)valvate, at least near its insertion, each petal enclosing a group of stamens, and the corolla is larger than the calyx in advanced bud (it is usually smaller in rosids). Lignified cells are found in the insides of the ovary loculi. These and many other similarities strongly link the old Tremandraceae and Elaeocarpaceae (Matthews & Endress 2002a), although some, like basifixed anthers, may be connected with buzz pollination.

Leaf teeth have a single vein running to an opaque (non)glandular deciduous apex. Juvenile leaves of Sloanea may be pinnate. The petals may vary considerably in width within the same flower; in some species they are connate. The androecium is extremely variable, although sometimes when there are many stamens they are clearly fasciculate. Some Elaeocarpus have curved embryos. All in all, and even aside from the inclusion of Tremandraceae, Elaeocarpaceae are variable. Tremandraceae are ericoid shrublets with unilacunar nodes and lacking stipules (again the correlation); the pedicels are not articulated. The flowers are solitary, axillary, the corolla is induplicate-valvate and entire, disc [Tremandra] +, there are twice as many stamens as petals, and in Tetratheca these stamens are enveloped in pairs by the petals; the anthers dehisce by pores, having a long tube or not; the gynoecium is two-carpelllate and flattened with 1-2 apical pendulous epitropous ovules/carpel in a single row; and the inner integument is up to 25 cells across. The seed has a chalazal aril.

Information on wood anatomy is taken from Gasson (1996), and that on seed anatomy, etc., of Tremandraceae from Boeswinkel (1999 - he notes that it is very similar to that of Linaceae). See Coode (2004) for a general account of the expanded family.

Phylogeny. In Bradford and Barnes (2001) monophyly of Elaeocarpaceae is not established, but sampling in that part of Oxalidales was poor. However, monophyly is strongly supported in the more detailed analysis of Crayn et al. (2006: 88% bootstrap, 99% posterior probability). There the well-supported clade [Sloanea [Vallea + Aristotelia]] was sister to the rest of the family, [Crinodendron + Peripentadenia] and Dubouzetia perhaps being successively sister to the remainder, where taxa from three genera of the old Tremandraceae were strongly supported as sister to a clade made up of Sericolea, Aceratium and Elaeocarpus, but there was little internal resolution of this clade.

Previous Relationships. Elaeocarpaceae were previously usually placed either in (Cronquist 1981) or adjacent to (Takhtajan 1997) Malvales, but there are numerous differences (e.g. absence of mucilage, indumentum type). Tremandraceae have long been of very uncertain position, for example, they were placed in Rosidae-Vochysiales (Takhtajan 1997) or Pittosporales (Cronquist 1981).

Synonymy: Aristoteliaceae Dumortier, Tetrathecaceae R. Brown, Tremandraceae Candolle, nom. cons.

Brunelliaceae + Cephalotaceae: inflorescence cymose; P uniseriate; G free, placentation basal, styles recurved, stigma decurrent; fruit a follicle.

Chemistry, Morphology, etc. An odd couple, but Cephalotaceae will make strange bed-fellows wherever they go, but see Matthews and Endress (2006b) for other characters possibly linking the two.

BRUNELLIACEAE Engler, nom. cons.   Back to Oxalidales

Woody; chemistry?; cork?; vessel elements with simple and scalariform perforations; (nodes 5:5); petiole bundles annular or D-shaped, wing bundles +/0; stomata actinocyclic (anomocytic); hairs unicellular; leaves opposite, stipellate, leaflet vernation conduplicate, 2ndaries prominent, proceeding to the (doubly toothed) margin, stipules cauline; breeding system various; flowers small, 4-8-merous; A 2(-3)x P, obdiplostemonous; pollen reticulate(-rugulate) to punctate; nectary +; G 2-8, carpels also alternating with C; ovules 2/carpel, epitropous, inner integument ca 4 cells across, obturator +; endocarp separating from the rest in fruit, K persistent; seeds shiny, raphe ± aril-like, coat with subepidermal sclerenchymatous layer and palisade innermost layer; endosperm mealy, embryo ?incumbent; n = 14.

1[list]/55. Central and South America and the Antilles; more or less montane (map: from Cuatrecasas 1970; note that Orozco Pardo 2002 does not include the easterly locations in South America). [Photo - Flower, Fruit.]

• Brunelliaceae may be recognised by their dense brown indumentum, their robust, rather flattened twigs, their opposite, usually odd-pinnately compound leaves with strongly serrate stipellate leaflets, and their rather small, paired cauline stipules (cf. Cunoniaceae!). The flowers are apetalous and have separate carpels and long-decurrent stigmas, and the fruits consist of groups of spreading and hairy follicles containing one or two shiny seeds that have an red, aril-like raphe down one side.

Chemistry, Morphology, etc. The nodes are described as being unilacunar (Orozco Pardo 2002; Orozco & Coba 2002), but there is some confusion here, and some nodes illustrated by Orozco Pardo (2002) certainly do not look unilacunar. The inner androecial whorl may have twice as many stamens as perianth members. There are pistillodes in staminate flowers and staminodes in carpellate flowers. The ovules are epitropous, unlike those of most Cunoniaceae. Pollen morphology is uninformative (Orozco 2001b). There are often five traces to each carpel. Orozco Pardo (2002) described the seeds as being arillate.

For general information, see Cuatrecasas (1970, 1985), Orozco Pardo (2002) and Kubitzki (2004b), for anatomy, Gregory (1998) and Orozco and Coba (2002), and for seed coat (which needs more study), Naranho and Huber (1971) and Danilova (1996).

Phylogeny. Orozco Pardo (2002) provides a morphology-based species level phylogeny of Brunelliaceae, together with comments on the biogeography of the genus.

CEPHALOTACEAE Dumortier, nom. cons.   Back to Oxalidales

Insectivorous herbs; flavanols and ellagic acid +, tannin 0; cork?; vessel elements with ?scalariform perforations; true tracheids +; young stem with vascular cylinder; nodes ?1:1; petiole bundles annular; stomata anomocytic; leaves spiral, simple, margins entire, some ascidiate, stipules 0; inflorescence scapose, racemose, branches scorpioid cymes; flowers 6-merous, hypanthium +, broad; P cucullate; nectary with glandular projections, esp. alternating with P; anther connective with a glandular tip; G 6, carpels plicate, loculi filled with secretion; ovules 1(2)/carpel, ?type, micropyle bi/endostomal, inner integument 3-5 cells across; hypanthium accrescent in fruit; seed coat mostly collapsed, exotesta papillate; endosperm development?, slight embryo long, accumbent; n = 10.

1[list]/1: Cephalotus follicularis. S.W. Australia (map: from Vester 1940). [Photo - Habit, Plant © H. Schneider.]

• Cephalotacaceae are insectivorous herbs that may be recognised by their rosette of leaves, some of which are fluted pitchers with lids (the leaves are reported to look like "vegetable hedgehogs" when young!), and scapose inflorescences with cymose branches. The six-merous flowers are small, lack petals, and have free carpels.

Evolution. Ecology & Physiology. There are nectar glands in the mouth of the pitcher which may faciltate the capture of insects (Bauer et al. 2008); Cephalotus produces enzymes in the pitcher (Peroutka et al. 2008b; Adlassnig et al. 2011).

Chemistry, Morphology, etc. Some information is taken from Diels (1930a), Jay and Lebreton (1973), Danilova (1996), Gregory (1998: anatomy), Conran (2004: general) and the Carnivorous Plants Database; see also MacFarlane (1911), Lloyd (1942), Juniper et al. (1989) and McPherson (2010).

Chemistry, Morphology, etc. Cephalotaceae were included in a heterogeneous Rosales by Cronquist (1981) where they were surrounded by families now included in Saxifragales; Cephalotales immediately followed Saxifragales in the system of Takhtajan (1997).