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The families of flowering plants

L. Watson and M.J. Dallwitz

Agdestidaceae Nak.

~ Phytolaccaceae.

Habit and leaf form. Scandent herbs (with turniplike rootstock). Perennial. Climbing; stem twiners. Leaves alternate; flat; long petiolate (the petioles twisted near the base); non-sheathing; simple. Lamina entire; ovate; pinnately veined; cross-venulate; cordate. Leaves exstipulate. Lamina margins entire.

Leaf anatomy. Stomata present; anomocytic.

Axial (stem, wood) anatomy. Secondary thickening anomalous (with successive rings of vascular bundles).

Reproductive type, pollination. Plants hermaphrodite.

Inflorescence, floral, fruit and seed morphology. Flowers aggregated in ‘inflorescences’; in panicles. The ultimate inflorescence units cymose (cymules). Inflorescences loose, axillary; panicles of cymules. Flowers bracteate; bracteolate; fragrant. Free hypanthium absent.

Perianth sepaline (corolla absent); 4(–5); 1 whorled. Calyx 4(–5); 1 whorled; polysepalous; regular; persistent; accrescent (these becoming stellately and reticulately veiny in the fruit).

Androecium 15–20. Androecial members free of the perianth (inserted on a thin perigynous disk); all equal; free of one another; ‘in more than one series’. Androecium exclusively of fertile stamens. Stamens 15–20; triplostemonous to polystemonous; filantherous (the filaments filiform). Anthers dorsifixed (oblong, bifid at each end); dehiscing via longitudinal slits.

Gynoecium (3–)4 carpelled. Carpels reduced in number relative to the perianth, or isomerous with the perianth. The pistil (3–)4 celled. Gynoecium syncarpous; synstylovarious; partly inferior. Ovary (3–)4 locular. Gynoecium stylate. Styles 1; apical; shorter than the ovary (short, conical). Stigmas 3–4 (recurved). Placentation basal to axile. Ovules 1 per locule; funicled; hemianatropous.

Fruit non-fleshy; indehiscent; achene-like (turbinate, unilocular by abortion, the leathery pericarp adherent to the seed, winged by the persistent, dry calyx); 1 seeded. Seeds probably non-endospermic. Perisperm presumably present (represented by ‘thin, mealy endosperm’). Embryo well differentiated. Cotyledons 2. Embryo curved (more or less annular).

Physiology, phytochemistry. Alkaloids absent. Iridoids not detected. Proanthocyanidins absent. Sieve-tube plastids P-type; type III (a).

Geography, cytology. Neotropical. Tropical. Central America and tropical South America.

Taxonomy. Subclass Dicotyledonae; Crassinucelli. Dahlgren’s Superorder Caryophylliflorae; Caryophyllales. Cronquist’s Subclass Caryophyllidae; Caryophyllales. APG 3 core angiosperms; core eudicot; Superorder Caryophyllanae; Order Caryophyllales (as a synonym of Phytolaccaceae).

Species 1. Genera 1; only genus, Agdestis.

General remarks. Apart from a wood anatomical character which may reflect inadequate sampling, Agdestis differs from Phytolaccaceae sensu stricto (q.v.) mainly in gynoecium characters (ovary partly inferior, synstylovarius, hemianatropous ovules) and the achene-like fruit.

Illustrations. • Technical details: Agdestis (Hutchinson).

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: 13th March 2017.’.