Heteropyxidaceae Engler & Gilg
~ Myrtaceae
Habit and leaf form. Small trees. Leaves alternate; spiral; petiolate; non-sheathing; gland-dotted (pellucid punctate); simple. Lamina entire; pinnately veined (without an intramarginal vein); cross-venulate. Leaves stipulate. Lamina margins entire. Domatia recorded; represented by pockets.
Leaf anatomy. Lamina with secretory cavities.
Stem anatomy. Internal phloem present (?). Secondary thickening developing from a conventional cambial ring. Xylem with fibre tracheids; without libriform fibres.
Reproductive type, pollination. Plants hermaphrodite.
Inflorescence, floral, fruit and seed morphology. Flowers aggregated in ‘inflorescences’; in panicles. Inflorescences terminal; terminal thyrses. Flowers small; regular; 5 merous; cyclic; tetracyclic. Free hypanthium present (the corolla ‘inserted on the calyx tube’).
Perianth with distinct calyx and corolla; 10; 2 whorled; isomerous. Calyx 5; 1 whorled; polysepalous, or gamosepalous; five blunt-lobed; regular; persistent; scarcely imbricate, or open in bud. Corolla 5; 1 whorled; polypetalous (the small petals inserted on the hypanthium/calyx tube). Petals shortly clawed (and gland dotted).
Androecium 5. Androecial members free of the perianth (inserted on the tube); all equal; free of one another; 1 whorled. Androecium exclusively of fertile stamens. Stamens 5; isomerous with the perianth; alternisepalous; opposite the corolla members; inflexed in bud. Anthers dorsifixed; dehiscing via longitudinal slits; introrse; appendaged (with a well developed connective gland). The anther appendages apical. Pollen grains aperturate; 3 aperturate; (parasyn-) colporate.
Gynoecium 2–3 carpelled. Carpels reduced in number relative to the perianth. The pistil 2–3 celled. Gynoecium syncarpous; eu-syncarpous; superior. Ovary 2–3 locular; sessile. Gynoecium stylate. Styles 1; from a depression at the top of the ovary; apical; short, persistent. Stigmas 1; capitate. Placentation axile (the ovules over most of the peltate placenta). Ovules 30–50 per locule (‘many’, no ovulodes); hemianatropous, or campylotropous (?).
Fruit non-fleshy; dehiscent; a capsule. Capsules loculicidal (small, 2–3 locular). Seeds non-endospermic. Cotyledons 2; flat. Embryo straight.
Geography, cytology. Paleotropical. Tropical. South Africa.
Taxonomy. Subclass Dicotyledonae; Crassinucelli. Dahlgren’s Superorder Myrtiflorae; Myrtales. Cronquist’s Subclass Rosidae; Myrtales. APG (1998) Eudicot; core Eudicot; Rosid; Eurosid II; Myrtales. Species 3. Genera 1; only genus, Heteropyxis.
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).