Memecylon L.

Scientific Description

Family Melastomataceae.

Habit and leaf form. Small to medium trees, or shrubs. Young stems cylindrical, or oval in section. Mesophytic. Leaves opposite; decussate; petiolate (petiole short to very short); simple. Leaf blades entire; lanceolate, or oblong, or ovate; elliptic, or ovate, or obovate, or orbicular; 1 -nerved; pinnately veined (with a single midrib); cross-venulate. Leaves without stipules. Leaf blade margins entire, or serrate. Leaves without a persistent basal meristem. Leaf anatomy. Hairs absent. Stem anatomy. Secondary thickening developing from a conventional cambial ring, or anomalous; from a single cambial ring.

Reproductive type, pollination. Fertile flowers hermaphrodite. Unisexual flowers absent. Plants hermaphrodite. Entomophilous.

Inflorescence and flower features. Flowers aggregated in ‘inflorescences’; in cymes, or in umbels, or in fascicles. The terminal inflorescence unit cymose. Inflorescences axillary; inflorescence usually axillary or cauline, simple to compound cymes or reduced to umbels or fascicles. Flowers pedicellate; bracteate; bracteolate; regular; 4 merous; cyclic. Free hypanthium present; campanulate (usually), or turbinate, or urceolate; extending beyond ovary; glabrous, adnate to ovary. Perianth with distinct calyx and corolla; 8; 2 -whorled; isomerous. Calyx present; 4; 1 -whorled; gamosepalous; entire, or lobed; if not entire, blunt-lobed, or toothed; valvate, or open in bud; regular; persistent. Corolla present; 4; 1 -whorled; polypetalous; contorted; regular; white, or pink, or purple, or blue. Petals oblong, or ovate, or orbicular. Androecial members definite in number. Androecium 8. 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. Stamens 8; all more or less similar in shape; diplostemonous. Anthers basifixed; versatile; dehiscing via short slits, or dehiscing via longitudinal slits; bilocular; initially tetrasporangiate (bisporangiate when mature); appendaged (from the connective, which has a dorsal, concave gland). Gynoecium (3–)4–5 carpelled. The pistil 1 celled. Gynoecium syncarpous; eu-syncarpous; inferior. Ovary unilocular; 1 locular. Gynoecium stylate. Styles 1; apical. Stigmas 1. Placentation free central. Ovules in the single cavity 3–10; ascending; whorled; anatropous.

Fruit and seed features. Fruit fleshy; indehiscent; a berry; 1(–2) seeded. Seeds non-endospermic. Embryo well differentiated (large). Cotyledons 2 (equal).

Geography, cytology, number of species. World distribution: pantropical.

Etymology. From the Greek memecylon; name used by Dioscorides and by Pliny, spelt memaecylon, for the fruit of the strawberry tree, Arbutus unedo.