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The families of flowering plants

L. Watson and M.J. Dallwitz

Tetracarpaeaceae (Engl.) Nak.

~ Escalloniaceae, Grossulariaceae, Haloragidaceae, Saxifragaceae.

Habit and leaf form. Low shrubs; leptocaul. Mesophytic. Leaves persistent; small; alternate; leathery; petiolate; non-sheathing; not gland-dotted; simple. Lamina entire; oblong, or ovate; pinnately veined; cross-venulate. Leaves exstipulate. Lamina margins doubly serrate. Leaf development not ‘graminaceous’.

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

‘Included’ phloem absent.

Reproductive type, pollination. Plants hermaphrodite.

Inflorescence, floral, fruit and seed morphology. Flowers aggregated in ‘inflorescences’; in racemes. The ultimate inflorescence units racemose. Inflorescences terminal; erect racemes. Flowers bracteate; small; regular; 4–5 merous; cyclic; pentacyclic. Free hypanthium present (? — “with a short calyx tube”).

Perianth with distinct calyx and corolla; 8, or 9; 2 whorled; isomerous, or anisomerous. Calyx 4, or 5; 1 whorled; shortly gamosepalous (basally). Calyx lobes markedly longer than the tube. Calyx regular; persistent; imbricate. Corolla 4; 1 whorled; polypetalous; imbricate; regular; white; deciduous (caducous). Petals clawed.

Androecium 8. Androecial members free of the perianth; coherent; 1 adelphous (the filaments very shortly connate); 2 whorled. Androecium exclusively of fertile stamens. Stamens 8; diplostemonous; both alternating with and opposite the corolla members. Anthers basifixed; non-versatile; dehiscing via longitudinal slits; latrorse. Pollen grains aperturate; 3 aperturate; colpate (?).

Gynoecium 4 carpelled. Carpels isomerous with the perianth. Gynoecium apocarpous; eu-apocarpous; superior. Carpel sub non-stylate; apically stigmatic; 15–100 ovuled (‘many’). Placentation marginal (ventral). Ovules anatropous; unitegmic; embryology not recorded.

Fruit fleshy; an aggregate. The fruiting carpel dehiscent; a follicle. Fruit 15–100 seeded (‘many’). Seeds endospermic.

Geography, cytology. Temperate. Tasmania.

Taxonomy. Subclass Dicotyledonae; Crassinucelli, or Tenuinucelli (? — polypetalous, but exstipulate and with unitegmic ovules). Dahlgren’s Superorder Corniflorae (?); Cornales (?). Cronquist’s Subclass Rosidae; Rosales. APG III core angiosperms; core eudicot; unplaced at Superordinal level. APG IV Order Saxifragales.

Species 1 (Tetracarpaea tasmannica). Genera 1; only genus, Tetracarpaea.

Illustrations. • Tetracarpaea tasmannica: Hook. Ic. Pl. III (1840).

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: 5th March 2018.’.