The families of flowering plants

L. Watson and M.J. Dallwitz

Aphanopetalaceae Endl.

~ Cunoniaceae in older systems.

Habit and leaf form. Straggling lianas (with stems having prominent lenticells). More or less, self supporting, or climbing; scrambling. Mesophytic, or xerophytic (in riparian scrub in Eastern Australia, or limestone crevices in Western Australia). Leaves opposite (4–10 cm long); leathery; shortly; simple (not articulated on the petiole). Lamina entire; ovate, or lanceolate (or elliptic-lanceolate); pinnately veined; obtuse or shortly acuminate, attenuate to the base. Leaves stipulate to exstipulate (? - "with minute toothed structures around the internodes"). Lamina margins obtusely slightly serrate, or entire; flat.

Reproductive type, pollination. Plants hermaphrodite.

Inflorescence, floral, fruit and seed morphology. Flowers aggregated in ‘inflorescences’; in racemes, or in panicles (lax). The ultimate inflorescence units cymose, or racemose (?). Inflorescences axillary; few flowered, short cymes or sometimes loose panicles. Flowers small (about 12 mm long); regular; 4 merous; tricyclic, or tetracyclic. Free hypanthium present (adnate to the lower half of the ovary wall, above which the perianth members and stamens separate).

Perianth with distinct calyx and corolla, or sepaline (the presence of petals can vary among different flowers of the same individual); 4, or 8; 1 whorled, or 2 whorled; when 2-whorled, isomerous. Calyx 4 (white or cream, petaline); 1 whorled; basally gamosepalous. Calyx lobes markedly longer than the tube. Calyx regular; persistent; accrescent; imbricate. Corolla when present 4 (minute); 1 whorled; when present, alternating with the calyx; polypetalous; regular.

Androecium 8. Androecial members free of the perianth, or adnate (each petal segment, when present, basally adnate with the staminal filament in the same radius above the level of separation from the ovary); all equal; free of one another; 2 whorled. Androecium exclusively of fertile stamens. Stamens 8; diplostemonous. Anthers dorsifixed to basifixed; non-versatile; dehiscing via longitudinal slits.

Gynoecium 4 carpelled. Carpels isomerous with the perianth. The pistil 4 celled. Gynoecium syncarpous; synovarious to synstylovarious; partly inferior (one-quarter to half inferior). Ovary 4 locular. Gynoecium stylate. Styles 4; partially joined (separating only near their apices, resulting in "a four-lobed style"); apical. Stigmas 4; dry type (?); papillate (?); Group II type (?). Placentation axile. Ovules 1 per locule; pendulous; non-arillate; anatropous.

Fruit non-fleshy; not an aggregate; indehiscent; a nut (surrounded by the persistent calyx). Seeds endospermic (?); minute. Cotyledons 2. Embryo straight.

Geography, cytology. Australian. Temperate. Southern Queensland and New South Wales (A. resinosum) and S.W. Western Australia (A. clematidum).

Taxonomy. Subclass Dicotyledonae; Crassinucelli. Dahlgren’s Superorder Rosiflorae; Cunoniales. Cronquist’s Subclass Rosidae; Rosales. APG III core angiosperms; core eudicot; unplaced at Superordinal level. APG IV Order Saxifragales.

Species 2. Genera 1; Aphanopetalum.

Quotations This description lacks information on “esoteric characters” (anther development, embryology, anatomy, phytochemistry, etc.); and Aphanopetalum needs pursuing with special reference to features diagnostic for Cunoniaceae (e.g., zigzag micropyle?).

Illustrations. • Aphanopetalum resinosum: Bauer, in Endlicher, Ic. Gen. Pl. (1838). • Aphanopetalum resinosum: A. Forster, 1938.

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.’.