Vivianiaceae Klotzsch.
~ Geraniaceae, Ledocarpaceae
Including Rhynchotheceae (Rhynchothecaceae) J.G. Agardh
Habit and leaf form. Basally woody herbs, or shrubs (much branched, spreading); non-laticiferous and without coloured juice. Leaves opposite; flat; not gland-dotted; 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.
Stem anatomy. Secondary thickening developing from a conventional cambial ring. Wood partially storied (VPI); parenchyma paratracheal (scanty). Sieve-tube plastids S-type.
Reproductive type, pollination. Fertile flowers hermaphrodite. Plants hermaphrodite.
Inflorescence, floral, fruit and seed morphology. Flowers aggregated in ‘inflorescences’; in cymes. The terminal inflorescence unit 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; non-petaloid. 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 plurilocular; 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, biochemistry. Betalains absent.
Geography, cytology. Neotropical. Temperate. Temperate South America.
Taxonomy. Subclass Dicotyledonae; Crassinucelli. Dahlgren’s Superorder Rutiflorae (?); Geraniales (?). Cronquist’s Subclass Rosidae; Geraniales. APG (1998) Eudicot; core Eudicot; Rosid; unassigned to Eurosid I or Eurosid II; Geraniales. Species 30. Genera 2; Viviania, Rhynchotheca.
Illustrations. • Technical details (Viviana).
Cite this publication as: ‘L. Watson and M. J. Dallwitz (1992 onwards). The Families of Flowering Plants: Descriptions, Illustrations, Identification, and Information Retrieval. Version: 14th December 2000. http://biodiversity.uno.edu/delta/’. Dallwitz (1980), Dallwitz, Paine and Zurcher (1993, 1995, 2000), and Watson and Dallwitz (1991) should also be cited (see References).
