Elaeodendron Jacq.

Scientific Description

Family Celastraceae.

Sometimes included in Cassine. The single Western Australian species is included in Elaeodendron (Islam et al. 2006) rather than Cassine (as in Jessup, Flora of Australia) on the basis of phylogenetic analysis.

Habit and leaf form. Trees, or shrubs; laticiferous, or non-laticiferous and without coloured juice. Stem internodes solid. Leaves opposite (usually), or alternate to opposite (sometimes sub-opposite, not distinctly alternate in Australia); ‘herbaceous’, or leathery; petiolate; non-sheathing; simple. Leaf blades dissected, or entire; elliptic, or obovate; pinnately veined; cross-venulate; cuneate at the base. Leaves with stipules. Stipules minute; caducous. Leaf blade margins entire, or crenate, or serrate. Leaves without a persistent basal meristem. Leaf anatomy. Hairs absent. Extra-floral nectaries absent.

Reproductive type, pollination. Fertile flowers hermaphrodite, or functionally male and functionally female, or functionally male, or functionally female. Unisexual flowers present, or absent. Plants hermaphrodite, or monoecious, or dioecious (in West Australian species). Female flowers with staminodes (3(-4) staminodes present). Male flowers with pistillodes (West Australian species). Entomophilous.

Inflorescence and flower features. Flowers aggregated in ‘inflorescences’; in cymes (simple or compound dichasial). The terminal inflorescence unit cymose, or racemose. Inflorescences axillary; mostly cymes or fascicles. Flowers pedicellate (short, West Australian species not articulate); ebracteate; ebracteolate; usually small; regular; 4–5 merous; cyclic; nearly always tetracyclic. Hypogynous disk present; intrastaminal; annular. Perianth with distinct calyx and corolla; (4–)8–10; 2 -whorled; isomerous. Calyx present; 3–5; 1 -whorled; gamosepalous (connate towards the base); blunt-lobed (irregularly multilobed); imbricate, or valvate; regular. Calyx lobes broadly ovate. Corolla present; 3–5; 1 -whorled; polypetalous; imbricate; regular; greenish yellow. Petals oblong to ovate, or orbicular (or subrotund). Fertile stamens present, or absent. Androecial members definite in number. Androecium 3–5. Androecial members free of the perianth; all equal; free of one another; 1 -whorled, or 2 -whorled. Androecium exclusively of fertile stamens, or including staminodes. Staminodes sometimes (2–)3–5 (alternating with the stamens). Stamens 3–5; all more or less similar in shape; isomerous with the perianth; oppositisepalous (on disc margin; in female flowers staminodes inside the disc margin). Anthers versatile; dehiscing via longitudinal slits; extrorse, or introrse; unilocular to bilocular; bisporangiate, or tetrasporangiate. Pollen shed in aggregates, or shed as single grains; when in aggregates in tetrads, or in polyads. Fertile gynoecium present, or absent (in functionally male flowers). Gynoecium 2–5 carpelled (usually with all but one abortive). The pistil 3 celled. Gynoecium syncarpous; eu-syncarpous; superior (KL), or partly inferior (K). Ovary plurilocular; 3 locular (West Australian species); sessile. Gynoecium non-stylate (West Australian species), or stylate. Styles 1; attenuate from the ovary; apical. Stigmas 1; 2–3 - lobed, or 1 - lobed (entire in West Australian species). Placentation axile. Ovules 1–2 per locule; pendulous, or ascending; apotropous; with ventral raphe, or with dorsal raphe (when pendulous); anatropous.

Fruit and seed features. Fruit fleshy; dehiscent, or indehiscent; a capsule, or a berry, or a drupe, or a samara, or achene-like. Capsules loculicidal. Fruit 1–3 seeded (per locule). Seeds endospermic, or non-endospermic. Endosperm when present, ‘more or less’ oily. Seeds winged, or wingless. Embryo well differentiated. Cotyledons 2 (large, flat, foliaceous). Embryo straight.

Geography, cytology, number of species. World distribution: Mexico, the West Indies, Bermuda, Africa, Madagascar, India, Melanesia, New Caledonia and Australia

. Native of Australia. Not endemic to Australia. Australian states and territories: Western Australia, Northern Territory, Queensland, and New South Wales. Northern Botanical Province. A genus of 40 species; 1 species in Western Australia; 0 endemic to Western Australia.