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.
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, carinal, dry [not secretory]; ovules few [?1]/carpel, marginal, anatropous, bitegmic, micropyle endostomal, outer integument 2-3 cells across, often largely subdermal in origin, inner integument 2-3 cells across, often dermal in origin, parietal tissue 1-3 cells across [crassinucellate], nucellar cap?; megasporocyte single, hypodermal, 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]; 2C genome size 1-8.2 pg [1 pg = 109 base pairs], 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]]: benzylisoquinoline alkaloids 0; euAP3 + TM6 genes [duplication of paleoAP3 gene: B class], 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 , G  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.
[DILLENIALES [SAXIFRAGALES [VITALES + ROSIDS s. str.]]]: nodes 3:3; stipules + [usually apparently inserted on the stem].
[SAXIFRAGALES [VITALES + ROSIDS]] / ROSANAE Takhtajan / SUPERROSIDAE: ??
[VITALES + ROSIDS] / ROSIDAE: anthers articulated [± dorsifixed, transition to filament narrow, connective thin]. Back to Main Tree
Evolution. Divergence & Distribution. Using penalized likelihood, H. Wang et al. (2009: two estimates) suggested that the Vitaceae/rest of rosid split occurred (115-)111(-109) or (96-)92(-88) m.y.a.; two Bayesian relaxed clock estimates were between 119 and 113 m.y. Ages of (132-)125, 101(-97) m.y. are suggested by Bell et al. (2010 for details: Dilleniaceae in superasterids...). Wikström et al. (2001) suggested an age of (112-)108(-104) m.y., Magallón and Castillo (2009) estimated ages of ca 112.6 to 113.2 m.y., Argout et al. (2011) gave a date of ca 123 m.y., and Magallón et al. (2013) an age of around 108.7 m.y..
Genes & Genomes. For the possible palaeohexaploidy of Vitales, see Jaillon, Aury et al. (2007) and for genome synteny, transposition, etc., see Woodhouse et al. (2011). This genome triplication seems to have occurred in the common ancestor of the [rosid + asterid] clade, or even in the immediate ancestor of the core eudicots as a whole; for further information, see the Gunnerales page.
Chemistry, Morphology, etc. For disc nectaries, see Endress (2010c).
Phylogeny. Molecular data still do not link Vitaceae unambiguously with any other single core eudicot order, but they are definitely not nested within any group. They were placed sister to rosids, but with only moderate support (D. Soltis et al. 2000), and even this moderate support weakened in a subsequent four-gene analysis (D. Soltis et al. 2003a); however, Jansen et al. (2006a, b) using complete chloroplast genome sequences found quite strong support for this position (note that members of Berberidopsidales, Dilleniales, Santalales and Saxifragales were not included: see also Ruhlman et al. 2007; Jansen et al. 2007; Moore et al. 2007). Hilu et al. (2003: matK analysis [incomplete sequence] alone) suggest relationships between Vitales and Dilleniales (only moderate support in parsimony analysis, but 100% posterior probability in Bayesian analyses), the combined clade being just above Malpighiales and below Saxifragales in a pectinate tree of major clades within the core eudicots. Although this relationship was not recovered in the analysis of the matK gene by Worberg et al. (2007), the two do have a similar and rather distinctive testa anatomy (see also Kubitzki 2006a). See the Dilleniales and Saxifragales pages for further discussions on the relationships of Vitales. The placement adopted here, although somewhat tentative, seems quite likely.
VITALES Reveal Main Tree, Synapomorphies.
Vessel elements with simple perforation plates; tension wood 0; nodes 3-7:3-7; sieve tube plastids with protein crystalloids and starch; raphide bundles +; pearl glands + [food bodies]; leaves compound; C protective in bud; stamens = and opposite petals, from a common primordium; style short; ovules 2/carpel, apotropous, micropyle?; fruit a berry, K deciduous; seeds perichalazal, vascular bundle ± surrounding seed, ± ruminate and with Y-shaped dorsal infold, testa multiplicative, exotesta fleshy, mesotesta 2-17 layers across, endotesta 2-5-layered, lignified, crystalliferous, exotegmen (crossed) tracheidal, endotegmen ± mucilaginous; embryo minute. - 1 family, 14 genera, 850 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 for many characters, with with variation within and between clades. Furthermore, 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...
Synonymy: Leeales de Candolle
VITACEAE Jussieu, nom. cons. Back to Vitales
Ellagic acid, myricetin +; (cork cambium deep-seated); cambium storied; wood with broad rays; nodes often swollen; petiole with ring of bundles; stomata variable; branching from previous flush; leaves palmately compound or -veined, lamina vernation conduplicate, teeth glandular; inflorescences terminal, branched, paniculate-corymbose; flowers small, <1 cm across, (3-)5(-7)-merous; K connate, C valvate; tapetal cells 3-4-nucleate; pollen 3-celled; stigma capitate or 4-fid, dry; ovules apotropous, nucellar cap +, hypostase +, placental obturator + or 0; prominent raphe and chalazal knot, seed-coat ingrowths delimiting raphe; (endotesta palisade), exotegmen with spiral thickenings, endotegmen tanniniferous.
14/850 - 2 groups below. Pantropical and (warm) temperate.
1. Leeoideae Burmeister
Herbs to trees; raphides barbed; leaves spiral, to twice compound, teeth with small glandular apex, one lateral vein continues its course above the tooth, stipules borne along petiole margin, sheathing; C basally connate; stamens basally adnate to corolla, forming a tube with the alternating staminodial/nectary lobes; G [3 (4)], (semi-inferior), odd member abaxial, loculi divided; micropyle bistomal, outer integument 4-5 cells across, inner integument ca 2 cells across, parietal tissue ca 6 cells across, nucellar cap ca 2 cells across; seed-coat ingrowth at antiraphe, also paired, lateral, rarely raphides in the seed coat, mesotegmic cells divide once, expand, then collapse; n = (10-)12.
1[list]/34. Most Indo-Malesian, few Africa and Madagascar (map: from Ridsdale 1976; Trop. Afr. Fl. Pl. Ecol. Distr. 5. 2010; Australia's Herbarium i.2013; fossils [green] from Manchester et al. 2012b). [Photo - Flower]
Synonymy: Leeaceae Dumortier, nom. cons.
2. Vitoideae Eaton
Lianes (stout trees, herbs; rootstock swollen), climbing by leaf-opposed branch tendrils; raphides smooth; (cuticle waxes as tubular rodlets); (more than one bud/node); leaves opposite, spiral or two-ranked, (simple), lamina teeth with gland broadening distally and with foramen, veins from above and below, (stipules adaxially connate); inflorescences leaf-opposed (terminal); (flowers 4-merous); (K lacking vascular traces), (C connate by papillae and calyptrate); (tapetum plasmodial); (pollen binucleate); nectary gynoecial, lobes alternating with A, also annular (investing G; 0); G , transverse or vertical, (style long); micropyle endo(bi)stomal, outer integument 4-7 cells across, inner integument (1 - Vitis)2-3(-4) cells across, parietal tissue 3-20 cells across, in radial rows, nucellar cap 2-10 cells across; raphides in the seed coat; n = 10-16, 19, 20.
14[list]/825: Cissus (350), Cyphostemma (150: ?= Vitis), Ampelocissus (100), Tetrastigma (95), Vitis (65), Cayratia (65). Pantropical and (warm) temperate (map: from Wickens 1976; Meusel et al. 1978; Morley & Toelken 1983; Lombardi 2000; Fl. China 12. 2007; Trop. Afr. Fl. Pl. Ecol. Distr. 5. 2010; Australia's Virtual Herbarium xii.2012; Fl. Pakistan). [Photo - Flower]
Synonymy: Ampelidopsaceae Kosteletzky, Cissaceae Drejer, Pterisanthaceae J. Agardh
Evolution. Divergence & Distribution. Magallón and Castillo (2009) estimated ages of ca 90.7 m.y. for crown group Vitaceae.
Fossil leaves of assigned to Vitoideae are reported from the Late Cretaceous (see R. Burham's Fossil Record of Climbers for references), although wood (Wheeler " LaPasha 1994; Smith et al. 2012) and the distinctive seeds of the family are found only somewhat later, the latter in particular are quite common in both North America and Europe in deposits of Tertiary age. There may be more than twelve seeds per berry, which suggests a gynoecium unlike that of any extant member of the family (Manchester & Chen 2009), while features of the woods also represent unexpected combinations (Wheeler & LaPashs 1994). Fossils of seeds from the Late Eocene of Panama (perhaps 40-37 m.y. old) have been identified as c.f. Leea, a genus now restricted to the Old World (Herrera et al. 2012). Leea has also been found in younger Oligocene deposits 30-28.5 m.y. old from north coastal Peru, and fossils of Ampelocissus, whose nearest current localities are in Central America, are also found there (Manchester et al. 2012a, b).
Wikström et al. (2001) suggested that crown group Vitaceae started diverging 92-78 m.y. before present and Magallón and Castillo (2009) estimated ages of ca 90.75 m.y. (different penalized likelihood datings). Moline et al. (2013: HPD) estimate the age of crown group Leeoideae at (86.2-)72.1(-65.0) m.y., and perhaps an origin in the Indochina area, although the New World fossils are then difficult to explain. Liu et al. (2012) suggest ages for various clades within Cissus s.l. (the three clades mentioned below).
Ecology & Physiology. Vitaceae are a major clade of vines; they are all tendrillate and have adhesive pade. For how the pads may function and the possible role of small hooks on the shoots as mechanoreceptors - in Parthenocissus at least - see Steinbrecher et al. (2011). The tendrils are clearly stem structures, and some are replaced by inflorescences in fertile shoots, and part tendril-part inflorescences are not uncommon (Calonje et al. 2002 for development). In some species not all leaves have axillary buds, and there has been discussion as to whether the inflorescence/tendril is an evicted terminal shoot, or not (Wilson et al. 2002, and references).
Vitaceous lianes may develop wuite high root pressures , probablyrepairing embolisms in the xylem (Fisher et al. 1997; Tibbetts & Ewers 2000). In drier parts of Africa there are a number of non-climbing species of Cissus s.l. with swollen stems, and these species may have crassulacean acid metabolism.
Plant-Animal Interactions. Caterpillars of some lepidoptera are found on Vitaceae and Onagraceae alone (Forbes 1956) - and both contain raphides. The raphides of Vitis are bipartite, square in transverse section, and like an arrow-head in longitudinal section (Horner & Wagner 1995).
Tetrastigma in West Malesia is the only host of the giant parasite Rafflesia (Rafflesiaceae, Malpighiales), and at least some other Rafflesiaceae have this genus as their host. Some genes of Tetrastigma are expressed in the parasite and codon usage properties of many other Rafflesia genes are like those of its host, a degree of integration of two genomes unknown in any other host-parasite association (Xi et al. 2012a). Dating estimates are somewhat in conflict. P. Chen et al. (2011b: HPD) suggest ages of (65.3-)50.6(-36.4) m.y. for stem Tetrastigma, (49.3-)36.9(-25.7) m.y. for the crown group, well before the origin of crown group Rafflesia (for which, see Bendiksby et al. 2010). However, if crown group Rafflesiaceae are (95.9-)81.7(-69.5) m.y. old (Bendiksby et al. 2010) and all the family are associated with Tetrastigma in particular...
Pollination Biology. The Malesian Pterisanthes has remarkable flattened red to purplish inflorescence axes on which the flowers are scattered.
Genes & Genomes. Vitis, at least, has a massive mitochondrial genome largely as the result of the the expansion of intergenic spacers; some DNA from the mitochondrion may have migrated to the nucleus - very unusual (Goremykin et al. 2009a).
Economic Importance. See Terral et al. (2010) for the early history of the domestication of the grape.
Chemistry, Morphology, etc. In temperate Vitaceae there is pronounced vessel dimorphism while in tropical members of the family there is often distinctive cambial structure and hence secondary thickening patterns. The raphides of Vitis are bipartite, square in transverse section and like an arrow-head in longitudinal section (Horner & Wagner 1995). Food bodies, often called pearl glands, are common on the surface of the plant. They are multicellular, with a multiseriate stalk, sometimes with a stoma on the swollen head, and the central parenchymatic cells accumulate oils and sugars (Pavia et al. 2009).
Flowers have a common stamen-petal primordium. There is considerable variation in nectary morphology, from enveloping the ovary and forming little projections on top to being absent. Although Leea lacks an obvious nectary like that of Vitis, etc., developmental data show that the lobes on the staminal tube are comparable to a nectary (Gerrath et al. 1990); the part of the tube alternating with the stamens is supplied by several traces, leading Nair (1968) to suggest that it might represnet a number of stamens. The ovary has been described as being "anatomically parietal" (Brizicky 1965, for references). The egg apparatus of Cissus is reported to lie outside the ovule (Nair 1970 for references). For the distinctive ruminate seed of the family, see Periasamy (1962).
Some general information is taken from Lombardi (2000) and Timmons (2006); for vascular anatomy, see Wheeler and LaPasha (1994), for nodal anatomy and stipules, see Shah (1959), for phyllotaxis, Gerrath et al. (1998), for leaf teeth, Hickey and Wolfe (1975), for floral development, see Gerrath and Posluszny (1989 and references - Viticoideae), Timmons et al. (2007: some Viticoideae, useful table), and Gerrath et al. (1990: Leeoideae), for embryology, etc., see Nair (1970), Nair and Nambisan (1957), and Nair and Bajaj (1966), for seed anatomy in extant and fossil taxa, see Chen and Manchester (2007, 2011), for ovules and seeds, see Berlese (1892), and for a recent general summary, see Wen (2006, as Leeaceae and Vitaceae).
Phylogeny. Ingrouille et al. (2002) in a study of rbcL phylogeny considered in the context of morphological variation found little strong support for clades within Vitaceae. Subsequent studies using more genes (e.g. Soejima & Wen 2006) find somewhat more resolution, although support values and relationships of the clades other than the Cyphostemma-Cayratia-Tetrastigma clade are still rather uncertain (Rossetto et al. 2002; Wen et al. 2007; Wen 2008; Chen et al. 2011; Trias-Blasi et al. 2012: Leea placed sister to Dillenia without comment, but see rooting; Liu et al. 2012). Ren et al. (2011) found two main clades in Vitoideae, one included species with 4-merous flowers, the other, species with 5-merous flowers, and within which - especially the former - there is a fair bit of well-supported phylogenetic structure that is correlated with names in current use. There were six well supported clades in Liu et al. (2012), one the Cyphostemma-Cayratia-Tetrastigma clade again, three including species of Cissus (two entirely so), and the final two, which may form a single clade, include species of Vitis et al. and Parthenocissus et al.
For the phylogeny of Tetrastigma, host of Rafflesia, see P. Chen et al. (2011a). Vitis seems to be monophyletic, and the species hybridize (Tröndle et al. 2010).
Classification. Although Vitis and relatives and Leea are morphologically distinguishable, there are numerous features that unite the two and they are sister taxa in all phylogenetic studies; inclusion in a single family seems reasonable. The wood anatomy of Leea and Rhoicissus in particular is very similar.
Generic limits in Viticoideae need attention, for example, species of Cissus occur all over the tree, while Tetrastigma, although monophyletic, is embedded in Cayratia (e.g. P. Chen et al. 2011b).
Previous Relationships. The affinities of Vitaceae have long been uncertain. They were often associated with Rhamnaceae, since both have stamens opposite the petals, and Takhtajan (1997) placed them near Proteanae, in his Rosidae; Proteanae also have stamens opposite their tepals, but are otherwise very different.