The families of flowering plants
~ Geraniaceae, rather than Oxalidaceae.
Habit and leaf form. Stemless herbs. A thick taprooted perennial; with a basal aggregation of leaves. Leaves alternate; spiral; simple. Lamina dissected; pinnatifid. Leaves exstipulate.
Axial (stem, wood) anatomy. Primary vascular tissues in a cylinder, without separate bundles (with a ring of pericyclic sclerenchyma); collateral. Internal phloem absent. Cortical bundles absent. Medullary bundles absent. Secondary thickening absent (?).
Reproductive type, pollination. Fertile flowers hermaphrodite. Plants hermaphrodite.
Inflorescence, floral, fruit and seed morphology. Flowers aggregated in inflorescences; in cymes. The ultimate inflorescence units cymose. Inflorescences radical, pedunculate or epedunculate 19-flowered cymes. Flowers regular; 5 merous; cyclic; polycyclic. Floral receptacle developing a gynophore (the gynoecium attached to a central column). Free hypanthium absent.
Perianth with distinct calyx and corolla; 10; 2 whorled; isomerous. Calyx 5; 1 whorled; polysepalous; regular; persistent; strongly imbricate. Corolla 5; 1 whorled; polypetalous; contorted.
Androecium 15. Androecial members free of the perianth; free of one another; 3 whorled. Androecium exclusively of fertile stamens. Stamens 15; triplostemonous; filantherous (the filaments subulate, persistent). Anthers dorsifixed; dehiscing via longitudinal slits; introrse. Pollen grains aperturate; 3 aperturate; colporate.
Gynoecium 5 carpelled. Carpels isomerous with the perianth. The pistil 5 celled. Gynoecium syncarpous; eu-syncarpous; superior. Ovary 5 locular (and five lobed); stipitate. Gynoecium stylate (the style filiform). Styles 1; apical. Stigmas 1; capitate. Placentation axile. Ovules 20–50 per locule (many); biseriate; non-arillate; anatropous to campylotropous (becoming campylotropous after fertilization, via a bulge from the inner integument on the raphal side cf. Geraniaceae); bitegmic; crassinucellate. Outer integument contributing to the micropyle. Hypostase present. Endosperm formation ab initio nuclear, or cellular (subsequently, commencing around the embryo).
Fruit non-fleshy; tardily dehiscent; a capsule. Capsules irregularly loculicidal (unlike the specialized structure of typical of Geraniaceae). Seeds scantily endospermic. Embryo well differentiated. Embryo coiled (cochlear). Micropyle zigzag.
Physiology, phytochemistry. Sieve-tube plastids S-type.
Geography, cytology. Neotropical. Andes.
Taxonomy. Subclass Dicotyledonae; Crassinucelli. Dahlgrens Superorder Rutiflorae; Geraniales (?). Cronquists Subclass Rosidae; Geraniales. APG 3 core angiosperms; core eudicot; Superorder Rosanae; malvid; Order Geraniales (as a synonym of Geraniaceae).
Species 8. Genera 1; only genus, Hypseocharis.
General remarks. Boesewinkel (1988) shows that the embyology and seed structure resemble Geraniaceae rather than Oxalidaceae or Linaceae.
The descriptions are offered for casual browsing only. We strongly advise against extracting comparative information from them. This is much more easily achieved using 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).
Cite this publication as: ‘Watson, L., and Dallwitz, M.J. 1992 onwards. The families of flowering plants: descriptions, illustrations, identification, and information retrieval. Version: 2nd April 2015. delta-intkey.com’.