Family Connaraceae

Connaraceae R. Br.

Habit and leaf form. Trees, or shrubs, or lianas (commonly); non-laticiferous and without coloured juice. Self supporting, or climbing; climbers stem twiners. Leaves alternate; spiral; leathery; petiolate; non-sheathing; not gland-dotted; compound; unifoliolate, or ternate, or pinnate; exstipulate; without a persistent basal meristem.

Leaf anatomy. Mucilaginous epidermis present, or absent. Stomata paracytic (commonly), or cyclocytic, or diacytic (rarely).

Lamina dorsiventral; with secretory cavities, or without secretory cavities. Secretory cavities containing mucilage.

Stem anatomy. Secretory cavities present, or absent; with mucilage. Cork cambium present; initially superficial. Nodes tri-lacunar to multilacunar. Internal phloem absent. Secondary thickening developing from a conventional cambial ring, or anomalous; when anomalous, via concentric cambia (Rourea). ‘Included’ phloem present (Rourea), or absent. Xylem with libriform fibres; with vessels. Vessel end-walls simple. Wood parenchyma scanty paratracheal (typically, or absent).

Reproductive type, pollination. Plants hermaphrodite (usually), or dioecious.

Inflorescence, floral, fruit and seed morphology. Flowers aggregated in ‘inflorescences’; in panicles and in racemes. The ultimate inflorescence unit cymose, or racemose (?). Inflorescences terminal, or axillary. Flowers small; regular, or somewhat irregular; 5 merous. Free hypanthium absent. Hypogynous disk present (small), or absent.

Perianth with distinct calyx and corolla; (8–)10; 2 whorled; isomerous. Calyx (4–)5; 1 whorled; polysepalous, or gamosepalous; persistent; imbricate, or valvate; with the median member anterior (?). Corolla (4–)5; 1 whorled; polypetalous, or gamopetalous; imbricate (usually), or valvate (rarely); regular.

Androecium 10 (usually), or 5. Androecial members free of the perianth; often markedly unequal (the antesepalous members longer); free of one another, or coherent (below); when coherent 1 adelphous; usually 2 whorled. Androecium exclusively of fertile stamens, or including staminodes. Staminodes when present, 1–5; internal to the fertile stamens, or in the same series as the fertile stamens and internal to the fertile stamens (from the inner whorl). Stamens 5–10; isomerous with the perianth, or diplostemonous. Anthers dorsifixed; versatile; dehiscing via longitudinal slits; introrse. Pollen grains aperturate; 3(–4) aperturate; colpate, or colporate.

Gynoecium 1 carpelled, or 3 carpelled, or 5 carpelled, or 7 carpelled, or 8 carpelled (often 5 with 4 abortive). The pistil when monomerous or semicarpous, 1 celled, or 3 celled, or 5 celled, or 7 celled, or 8 celled. Gynoecium monomerous, or apocarpous; of one carpel, or eu-apocarpous, or semicarpous (carpels sometimes more or less connate basally); superior. Carpel apically stigmatic; 2 ovuled. Placentation marginal to basal (‘marginal’, cf. Leguminosae). Ovules ascending; collateral (but one usually abortive); arillate (often), or non-arillate; orthotropous (always?); 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. Endosperm formation nuclear.

Fruit non-fleshy; an aggregate, or not an aggregate (often a single follicle). The fruiting carpels coalescing into a secondary syncarp to not coalescing. The fruiting carpel dehiscent, or indehiscent; a follicle, or nucular. Seeds endospermic, or non-endospermic. Endosperm when present, oily.

Seedling. Germination cryptocotylar.

Physiology, biochemistry. Alkaloids absent (one species). Proanthocyanidins present; cyanidin and delphinidin. Flavonols present; kaempferol, quercetin, and myricetin. Ellagic acid absent (Connarus). Saponins/sapogenins absent.

Geography, cytology. Tropical. Pantropical. X = 13 or 14.

Taxonomy. Subclass Dicotyledonae; Crassinucelli. Dahlgren’s Superorder Rosiflorae (?); Cunoniales (? — re-assigned from Sapindales). Cronquist’s Subclass Rosidae; Rosales. APG 3 core angiosperms; core eudicot; Superorder Rosanae; fabid; Order Oxalidales.

Species 300–350. Genera 16; Agelaea, Burttia, Cnestidium, Cnestis, Connarus, Ellipanthus, Hemandradenia, Jollydora, Manotes, Pseudoconnarus, Rourea, Vismianthus.

On the basis of rbcL sequencing (Chase et al 1993) Connaraceae seem not to be allied to Sapindales/Rutales, but the above re-assignment to Dahlgren’s Cunoniales is tentative.

Illustrations.
• Technical details: Connarus (Thonner).
• Technical details: Connarus (Lindley).