The families of flowering plants

L. Watson and M.J. Dallwitz

Vivianiaceae Klotzsch.

~ Geraniaceae, Ledocarpaceae.

Including Rhynchotheceae (Rhynchothecaceae) J.G. Agardh; excluding Ledocarpaceae.

Habit and leaf form. Basally woody herbs, or shrubs (much branched, spreading); non-laticiferous, without coloured juice. Leaves opposite; flat; simple. Lamina entire; cross-venulate. Leaves exstipulate (but the opposite members of each pair connected by a transverse line). Lamina margins entire, or crenate to serrate.

Leaf anatomy. Stomata present; anomocytic.

Axial (stem, wood) anatomy. Secondary thickening developing from a conventional cambial ring.

The parenchyma paratracheal (scanty); wood partially storied (VPI).

Reproductive type, pollination. Unisexual flowers absent. Plants hermaphrodite.

Inflorescence, floral, fruit and seed morphology. Flowers aggregated in ‘inflorescences’; in cymes. The ultimate inflorescence units cymose. Inflorescences loosely or closely cymose, the pedicels often long. Flowers regular; 4 merous, or 5 merous; cyclic. Free hypanthium absent. Hypogynous disk present; extrastaminal; of separate members (these entire or bilobed, alternating with the petals).

Perianth with distinct calyx and corolla, or sepaline (the corolla sometimes lacking); 4–5, or 8, or 10; 1 whorled, or 2 whorled; isomerous. Calyx 4, or 5; 1 whorled; polysepalous, or gamosepalous; regular (parallel veined); imbricate, or valvate. Corolla when present, 4, or 5; 1 whorled; polypetalous; regular.

Androecium 8, or 10. Androecial members free of the perianth; all equal, or markedly unequal; free of one another. Androecium exclusively of fertile stamens, or including staminodes (if the ‘glands’ are staminodial). Staminodes if interpreted as present, 4, or 5. Stamens 8, or 10; diplostemonous; long filantherous. Anthers dehiscing via longitudinal slits. Pollen grains aperturate; 7–20 aperturate (? —‘many’); foraminate.

Gynoecium 2–3 carpelled. Carpels reduced in number relative to the perianth. The pistil 2–3 celled. Gynoecium syncarpous; synovarious to synstylovarious; superior. Ovary 2–3 locular; sessile. Gynoecium stylate. Styles 1, or 2–3 (‘divided almost to the base’); free, or partially joined; apical. Stigmas 2–3 (long). Placentation axile. Ovules 2 per locule; pendulous, or pendulous and ascending (one of each); superposed.

Fruit non-fleshy; dehiscent; a capsule. Capsules loculicidal and valvular (the valves persistent). Seeds copiously endospermic. Endosperm oily (and fleshy). Embryo well differentiated. Cotyledons 1. Embryo strongly curved, or coiled.

Physiology, phytochemistry. Betalains absent. Sieve-tube plastids S-type.

Geography, cytology. Neotropical. Temperate. Temperate South America.

Taxonomy. Subclass Dicotyledonae; Crassinucelli. Dahlgren’s Superorder Rutiflorae (?); Geraniales (?). Cronquist’s Subclass Rosidae; Geraniales. APG III core angiosperms; core eudicot; Superorder Rosanae; malvid. APG IV Order Geraniales.

Species 30. Genera 2; Viviania, Rhynchotheca.

Illustrations. • Viviana crenata: Lindley. • Rhynchotheca integrifolia: Humboldt, Bonpland & Kunth, Nov. Gen. et Spec. Plantarum t. 464 (1821). • Rhynchotheca integrifolia, Humboldt et al. t.464 legend.

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: 15th April 2018.’.