The families of flowering plants

L. Watson and M.J. Dallwitz

Ancistrocladaceae Planch.

Habit and leaf form. Lianas. Climbing; stem twiners (the branch tips twining), or scrambling (the branch tips hooked). Stem growth conspicuously sympodial. Leaves alternate; spiral; petiolate; non-sheathing; simple. Lamina entire; pinnately veined; cross-venulate. Leaves stipulate. Stipules caducous (minute). Domatia occurring in the family.

Leaf anatomy. The leaf lamina dorsiventral. Stomata present; mainly confined to one surface (abaxial); actinocytic. Hairs present; glandular. Complex hairs present; peltate. Adaxial hypodermis present, or absent.

Axial (stem, wood) anatomy. Cork cambium present; initially deep-seated. Primary vascular tissues in a cylinder, without separate bundles; collateral. Internal phloem absent. Cortical bundles absent. Medullary bundles absent. Secondary thickening developing from a conventional cambial ring.

The vessels solitary (mostly, usually), or radially paired, or in radial multiples, or in tangential arcs. The vessel end-walls very oblique; simple. The vessels without vestured pits. The axial xylem with tracheids; with fibre tracheids. The parenchyma well developed, usually in tangential bands. The secondary phloem not stratified.

Reproductive type, pollination. Plants hermaphrodite.

Inflorescence, floral, fruit and seed morphology. Flowers aggregated in ‘inflorescences’; in panicles, in spikes, and in cymes. The ultimate inflorescence units often apparently cymose (axillary or terminal). Inflorescences spikes, panicles or racemes representing lax or rarely condensed dichotomous cymes. Flowers small; regular to somewhat irregular, or very irregular. The floral irregularity involving the perianth (the calyx becoming very irregular in fruit). Flowers 5 merous; cyclic; tetracyclic.

Perianth with distinct calyx and corolla; 10; 2 whorled; isomerous. Calyx 5; 1 whorled; gamosepalous; unequal but not bilabiate (markedly unequal in the fruit), or regular; persistent; accrescent (forming a winged crown for the floating fruit); imbricate. Corolla 5; 1 whorled; polypetalous, or gamopetalous (at the base). Corolla lobes markedly longer than the tube. Corolla contorted; more or less fleshy.

Androecium 10, or 5 (rarely). Androecial members adnate (to the base of the corolla); markedly unequal (5 somewhat larger), or all equal (when only 5); coherent (at the bases of the filaments); 1 adelphous; 1 whorled. Androecium exclusively of fertile stamens. Stamens 10, or 5; isomerous with the perianth, or diplostemonous; usually both alternating with and opposite the corolla members. Anthers dehiscing via longitudinal slits; introrse, or latrorse. Pollen grains aperturate; 3(–4) aperturate; colporate.

Gynoecium 3 carpelled. Carpels reduced in number relative to the perianth. The pistil 1 celled. Gynoecium syncarpous; synovarious; partly inferior. Ovary 1 locular. Styles 3; free to partially joined. Stigmas 3. Placentation basal. Ovules in the single cavity 1; ascending; non-arillate.

Fruit non-fleshy; indehiscent; a nut. Dispersal unit the nut with its crown of sepals. Dispersal by water. Seeds endospermic. Endosperm ruminate; starchy. Seeds with starch. Cotyledons 2.

Seedling. Germination phanerocotylar.

Physiology, phytochemistry. Proanthocyanidins present; cyanidin and delphinidin. Flavonols present; kaempferol, quercetin, and myricetin.

Geography, cytology. Tropical. Tropical Africa to Western Malaysia.

Taxonomy. Subclass Dicotyledonae; Crassinucelli (presumably, though not recorded embryologically). Dahlgren’s Superorder Theiflorae; Theales. Cronquist’s Subclass Dilleniidae; Violales. APG III core angiosperms; core eudicot; Superorder Caryophyllanae. APG IV Order Caryophyllales.

Species 20. Genera 1; only genus, Ancistrocladus.

Illustrations. • Ancistrocladus heyneanus (Hutchinson). • Ancistrocladus heynianus: Wight (1853), Ic. Pl. Ind. Orient. 6. • Ancistrocladus hamatus, as S. vahlii: Trimen, Ill. Fl Ceylon (1893).

We advise against extracting comparative information from the descriptions. This is much more easily achieved using the DELTA data files or the interactive key, which allows access to the character list, illustrations, full and partial descriptions, diagnostic descriptions, differences and similarities between taxa, lists of taxa exhibiting or lacking specified attributes, distributions of character states within any set of taxa, geographical distribution, genera included in each family, and classifications (Dahlgren; Dahlgren, Clifford, and Yeo; Cronquist; APG). See also Guidelines for using data taken from Web publications.

Cite this publication as: ‘Watson, L., and Dallwitz, M.J. 1992 onwards. The families of flowering plants: descriptions, illustrations, identification, and information retrieval. Version: 5th March 2018.’.