The families of flowering plants
~ Celastraceae, Saxifragaceae sensu lato, Parnassiaceae.
Habit and leaf form. Diminutive herbs (with leaves brown-streaked from tannins). Plants more or less succulent. Annual. Leaves (sub) opposite, or alternate; simple. Lamina entire. Leaves exstipulate.
Axial (stem, wood) anatomy. Secondary thickening absent (?).
Reproductive type, pollination. Plants hermaphrodite.
Inflorescence, floral, fruit and seed morphology. Flowers solitary; terminal; ebracteolate; regular; 5 merous; cyclic; tetracyclic, or pentacyclic.
Perianth with distinct calyx and corolla, or sepaline (the corolla minute or missing); 5–10; 1 whorled, or 2 whorled. Calyx 5; 1 whorled; polysepalous; regular. Corolla when present, 1–5; 1 whorled; when recognisable, polypetalous (the petals tiny, round to spathulate).
Androecium 10. Androecial members free of the perianth and adnate; free of one another; 2 whorled. Androecium including staminodes. Staminodes 5; external to the fertile stamens (constituting an outer, epipetalous whorl). Stamens 5; isomerous with the perianth; oppositisepalous (very short). Pollen grains aperturate; 3 aperturate; colporate.
Gynoecium 3–4 carpelled. Carpels reduced in number relative to the perianth. The pistil 1 celled. Gynoecium syncarpous; synovarious; inferior. Ovary 1 locular. Gynoecium stylate. Styles 3–4; free; shorter than the ovary (very short). Stigmas 3; commissural (along with the styles); capitate. Placentation parietal. Ovules in the single cavity 30–100 (many).
Fruit non-fleshy; dehiscent; a capsule (globose, thin-walled). Capsules loculicidal. Seeds scantily endospermic (the endosperm layer one cell thick). Perisperm absent.
Geography, cytology. Holarctic and Neotropical. Southern U.S.A., Mexico, Chile.
Taxonomy. Subclass Dicotyledonae; Crassinucelli (? apetalous or polypetalous). Dahlgrens Superorder Theiflorae; Droserales. Cronquists Subclass Rosidae; Rosales. APG 3 core angiosperms; core eudicot; Superorder Rosanae; fabid; Order Celastrales (as a synonym of Celastraceae).
Species 1. Genera 1; Lepuropetalon (L. spathulatum).
General remarks. Differing from Celstraceae sensu stricto (q.v.) in the succulent, herbaceous habit without secondary thickening, as well as in conspicuous features of androecium and gynoecium.
Illustrations. • Lepuropetalon spathulatum: W.R. Carr (2007: www.biosci.utexas.edu).
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: 24th October 2017. delta-intkey.com/angio’.