Trema Lour.

Scientific Description

Family Ulmaceae.

Habit and leaf form. Trees, or shrubs; evergreen, or deciduous. Leaves cauline. Leptocaul. Mesophytic. Leaves alternate; distichous; petiolate; non-sheathing; simple. Leaf blades entire; narrowly elliptic to ovate; pinnately veined; cross-venulate; cordate, or oblique at the base, or rounded at the base. Leaves with stipules. Stipules intrapetiolar; free of one another (extrapetiolar); caducous. Leaf blade margins crenate, or serrate, or dentate. Vegetative buds scaly. Leaves without a persistent basal meristem. Leaf anatomy. Hairs present, or absent; glandular hairs present (multicellular). Stem anatomy. Secondary thickening developing from a conventional cambial ring.

Reproductive type, pollination. Fertile flowers hermaphrodite and functionally male, or hermaphrodite, functionally male, and functionally female. Unisexual flowers present. Plants monoecious, or polygamomonoecious (sometimes). Female flowers with staminodes (4–5 staminodes), or without staminodes. Male flowers with pistillodes (pistillode hirsute or small). Entomophilous.

Inflorescence and flower features. Flowers aggregated in ‘inflorescences’; in cymes (in a thyrse), or in panicles. The terminal inflorescence unit cymose, or racemose. Inflorescences axillary; male, female and bisexual flowers either in the same or separate inflorescences. Flowers bracteate (bracts minute). Bracts deciduous (caducous). Flowers small; regular; 4 merous, or 5 merous; cyclic. Free hypanthium present, or absent. Hypogynous disk absent. Perianth sepaline; 4–5; 1 -whorled; joined. Calyx present; (if the perianth is so interpreted 4, or 5; 1 -whorled; gamosepalous (connate at the base); blunt-lobed (lobes elliptic to ovate); valvate; regular; persistent. Androecium present, or absent (sometimes, from male flowers). Fertile stamens present, or absent (in female flowers). Androecial members definite in number. Androecium 4–5. Androecial members free of the perianth, or adnate; all equal; free of one another; 1 -whorled. Androecium exclusively of fertile stamens. Stamens 4–5; all more or less similar in shape; isomerous with the perianth; oppositisepalous; erect in bud. Anthers dorsifixed; dehiscing via longitudinal slits; introrse; tetrasporangiate. Fertile gynoecium present, or absent (male flowers). Gynoecium 2(–3) carpelled. The pistil 1 celled, or 2 celled. Carpels reduced in number relative to the perianth. Gynoecium syncarpous; synovarious to eu-syncarpous; superior. Ovary unilocular, or plurilocular; 1 locular, or 2 locular. Gynoecium median. Ovary sessile (ovoid). Gynoecium stylate. Styles 1–2; free to partially joined; apical. Stigmas 1. Placentation apical. Ovules in the single cavity 1; pendulous; non-arillate; campylotropous.

Fruit and seed features. Fruit fleshy (succulent); indehiscent; a drupe. Seeds endospermic, or non-endospermic. Cotyledons 2. Embryo curved.

Additional comments. Cyanogenic.

Etymology. Probably from the Greek for "the holes or pips of a dice"; refers to the pitting on the hard stone (endocarp) of the fruit.