The families of flowering plants
Including Belangeraceae J.G. Agardh, Callicomaceae J.G. Agardh; excluding Aphanopetalaceae, Baueraceae, Eucryphiaceae.
Habit and leaf form. Trees, shrubs, and lianas. Self supporting, or climbing. Leaves opposite, or whorled, or alternate (rarely); when alternate, spiral (Gumillea); leathery; petiolate; not gland-dotted; nearly always compound, or simple (sometimes); when compound, ternate, or pinnate; often conspicuously stipulate. Stipules interpetiolar (often), or intrapetiolar. Leaf development not graminaceous. Domatia occurring in the family (recorded in 3 genera); manifested as pits, or pockets, or hair tufts.
Leaf anatomy. The leaf lamina dorsiventral. Mucilaginous epidermis present. Stomata very small with the guard cells almost circular in outline in Cunonia and Platylophus. Hairs present, or absent (chiefly represented by infrequent unicellular types, but tufted ones recorded for Callicoma); eglandular (mostly), or glandular (shaggy, in Ceratopetalum and Cunonia). Adaxial hypodermis very commonly present (commonly mucilaginous). The mesophyll containing mucilage cells (rarely?), or not containing mucilage cells; with sclerenchymatous idioblasts, or without sclerenchymatous idioblasts; containing crystals, or without crystals. The crystals when recorded, druses and solitary-prismatic. Minor leaf veins without phloem transfer cells (Weinmannia).
Axial (stem, wood) anatomy. Pith sometimes quadrangular, usually heterogeneous. Secretory cavities absent (but secretory cells sometimes seen in cortex, pith and rays). Cork cambium present; initially superficial. Nodes tri-lacunar. Primary vascular tissues in a cylinder, without separate bundles; collateral. Internal phloem absent. Cortical bundles absent. Medullary bundles absent. Secondary thickening developing from a conventional cambial ring. Primary medullary rays narrow. The axial xylem with vessels.
The wood semi-ring porous (Anodopetalum, Platylophus), or diffuse porous. The vessels small (usually), or small to medium; solitary, or radially paired, or in radial multiples, or clustered, or in tangential arcs. The vessel end-walls somewhat oblique, or horizontal; simple, or scalariform, or scalariform and simple. The vessels without vestured pits; without spiral thickening. The axial xylem with tracheids, or without tracheids; without vasicentric tracheids; with fibre tracheids (usually), or without fibre tracheids; with libriform fibres (rarely), or without libriform fibres; usually without septate fibres. The fibres without spiral thickening. The parenchyma apotracheal (diffuse or banded). The secondary phloem not stratified. Included phloem absent. The wood not storied. Tyloses present, or absent.
Reproductive type, pollination. Plants hermaphrodite (usually), or dioecious, or androdioecious (rarely), or gynodioecious (rarely), or polygamomonoecious (rarely).
Inflorescence, floral, fruit and seed morphology. Flowers solitary, or aggregated in inflorescences; when aggregated, in cymes, in racemes, and in heads. The ultimate inflorescence units cymose, or racemose. Inflorescences usually compound. Flowers small; regular; cyclic, or partially acyclic. Sometimes the androecium acyclic. Hypogynous disk present (commonly), or absent (?).
Perianth with distinct calyx and corolla, or sepaline; (3–)5(–10), or (6–)10(–20); 1 whorled, or 2 whorled; isomerous. Calyx (3–)4–5(–10); 1 whorled; polysepalous, or gamosepalous (basally). Calyx lobes markedly longer than the tube. Calyx regular; imbricate, or valvate. Corolla when present, (3–)4–5(–10) (alternating with the calyx); 1 whorled; polypetalous, or gamopetalous (basally). Corolla lobes markedly longer than the tube. Corolla regular; not fleshy.
Androecium 4–5 (in one whorl opposite the calyx), or 8–10 (in two whorls), or 20–100 (often many). Androecial members unbranched; free of the perianth; all equal; free of one another; 1 whorled, or 2 whorled. Androecium exclusively of fertile stamens. Stamens 4–5, or 8–10, or 11–40; isomerous with the perianth, or diplostemonous, or polystemonous; when in one whorl, oppositisepalous. Anthers dorsifixed; versatile (mostly); dehiscing via longitudinal slits; introrse. Microsporogenesis simultaneous. Pollen shed as single grains. Pollen grains aperturate; 2 aperturate (often), or 3 aperturate; colpate, or colporate; 2-celled (in Caldcluvia).
Gynoecium 2 carpelled (usually), or 3–5 carpelled (rarely). The pistil when other than apocarpous, 2 celled, or 3 celled. Gynoecium syncarpous, or apocarpous (more or less, rarely); synovarious (usually), or eu-apocarpous to semicarpous (rarely); superior (usually), or partly inferior (Spiraeanthemum). Ovary when syncarpous 2 locular (usually), or 3–5 locular (rarely). Styles 2, or 3–5; free. Stigmas dry type; papillate; Group II type. Placentation axile, or apical. Ovules 2–50 per locule (i.e. to many); non-arillate; anatropous, or hemianatropous; bitegmic; crassinucellate. Outer integument contributing to the micropyle. Embryo-sac development Polygonum-type. Polar nuclei fusing prior to fertilization. Antipodal cells formed; 3; not proliferating; ephemeral. Synergids pear-shaped. Hypostase present (Ceratopetalum), or absent. Endosperm formation nuclear.
Fruit fleshy, or non-fleshy; not an aggregate, or an aggregate to not an aggregate. The fruiting carpel when apocarpous/semicarpous (i.e. rarely), dehiscent; a follicle. Fruit when syncarpous (i.e. usually), dehiscent, or indehiscent, or a schizocarp. Mericarps when schizocarpic, 2, or 3–5 (?). Fruit a capsule (usually), or a drupe (rarely), or a nut (rarely). Seeds endospermic. Endosperm oily. Seeds small; winged, or wingless. Cotyledons 2. Embryo usually straight. Micropyle zigzag.
Seedling. Germination phanerocotylar.
Physiology, phytochemistry. Cyanogenic (rarely), or not cyanogenic. Alkaloids present (rarely), or absent. Iridoids not detected. Proanthocyanidins present; cyanidin, or cyanidin and delphinidin. Flavonols present; quercetin, or kaempferol, quercetin, and myricetin. Ellagic acid absent (Callicoma, Ceratopetalum). Aluminium accumulation demonstrated (often).
Geography, cytology. Temperate to tropical. Malaysia, Australasia, South Africa, Central and South America - mostly between 13 degrees North and 35 South. X = 12, 15, 16.
Taxonomy. Subclass Dicotyledonae; Crassinucelli. Dahlgrens Superorder Rosiflorae; Cunoniales. Cronquists Subclass Rosidae; Rosales. APG 3 core angiosperms; core eudicot; Superorder Rosanae; fabid; Order Oxalidales.
Species 250. Genera about 20; Acrophyllum, Acsmithia, Aistopetalum, Anodopetalum, Caldcluvia, Callicoma, Ceratopetalum, Codia, Cunonia, Geissois, Gillbeea, Gumillea(?), Lamanonia, Pancheria, Platylophus, Pseudoweinmannia, Pullea, Schizomeria, Spiraeanthemum, Vesselowskya, Weinmannia.
General remarks. Comparisons with this attempt at a sensu stricto description show sufficient character differences to defend retaining Aphanopetalaceae, Baueraceae and Eucryphiaceae (q.v.) as distinct families.
Economic uses, etc. The woods of Ceratopetalum apetalum (coachwood, Australia) and Cunonia capensis (South Africa) are used for cabinet-work, and those of some others are used for tool handles, turnery, etc.
Illustrations. • Technical details: Cunonia, Weinmannia. • Technical details: Weinmannia (Thonner). • Technical details: Weinmannia (Lindley). • Geissois imthurnii: Hook. Ic. Pl. 31 (1916).
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: 12th September 2017. delta-intkey.com/angio’.