Rhynchocalycaceae Johnson and Briggs
~ Crypteroniaceae
Habit and leaf form. Small trees. Mesophytic. Leaves opposite (decussate), or whorled; petiolate; simple. Lamina entire; eucamptodromous. Leaves stipulate. Stipules intrapetiolar (axillary, ‘divided’).
Leaf anatomy. Stomata present; anomocytic.
The mesophyll without sclerenchymatous idioblasts.
Stem anatomy. Young stems cylindrical, or flattened. Nodes unilacunar (with one trace). Secondary thickening developing from a conventional cambial ring. Xylem without fibre tracheids; with libriform fibres (septate). Vessel end-walls oblique; simple. Vessels with vestured pits. Wood parenchyma scanty paratracheal (to vasicentric).
Reproductive type, pollination. Plants hermaphrodite.
Inflorescence, floral, fruit and seed morphology. Flowers aggregated in ‘inflorescences’; in panicles. Inflorescences terminal and axillary; anthotelic panicles. Flowers regular; 6 merous. Free hypanthium present. Hypogynous disk absent.
Perianth with distinct calyx and corolla; 12; 2 whorled. Calyx 6; 1 whorled; persistent (membranous); valvate. Corolla 6; 1 whorled; polypetalous; deciduous. Petals clawed (hoodlike, covering the stamens in bud).
Androecium 6. Androecial members free of the perianth (inserted in the mouth of the hypanthium); free of one another; 1 whorled. Androecium exclusively of fertile stamens. Stamens 6; isomerous with the perianth; alternisepalous; opposite the corolla members; initially incurved; filantherous (the filaments long, more or less flattened). Anthers dorsifixed to basifixed (the connective elliptical); bilocular (the sporangia lateral); tetrasporangiate. Endothecium ephemeral. Anther wall initially with more than one middle layer (2); of the ‘basic’ type. Tapetum glandular. Pollen shed as single grains. Pollen grains aperturate; 6 aperturate; colpate and colporate (tricolporate, with three subsidiary colpi); 2-celled.
Gynoecium 2 carpelled. Carpels reduced in number relative to the perianth. The pistil (1–)2 celled. Gynoecium syncarpous; eu-syncarpous; superior. Ovary (1–)2 locular (bilateral, compressed). Gynoecium stylate. Styles 1; apical; shorter than the ovary (stout, the base persistent). Stigmas 1; capitate (narrow). Placentation axile. Ovules 20–100 per locule (‘many’, or ‘about 40’); horizontal; anatropous; bitegmic; crassinucellate. Outer integument not contributing to the micropyle. Embryo-sac development Polygonum-type. Endosperm formation nuclear. Embryogeny onagrad.
Fruit non-fleshy; dehiscent; a capsule. Capsules loculicidal. Seeds non-endospermic; obliquely ovate, flattened; winged (at the micropylar end). Cotyledons 2. Embryo straight (apical).
Geography, cytology. Cape. Sub-tropical. Southern Africa (Natal and Transkei).
Taxonomy. Subclass Dicotyledonae; Crassinucelli. Dahlgren’s Superorder Myrtiflorae; Myrtales. Cronquist’s Subclass Rosidae; Myrtales. APG (1998) Eudicot; core Eudicot; Rosid; Eurosid II; Myrtales. Species 1. Genera 1; only genus, Rhynchocalyx.
Rather inadequate description, expanded from the brief Latin diagnosis of Johnson and Briggs (198 ) with reference to Graham (1984), Hiroshi and Raven, P.H. (1984) and standard works.
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).