Volume 7 > Part 3 > Year 2001 > Page 468 > Melastomataceae

11. Phyllagathis Blume

Flora 14: 507. 1831; Hansen, Bull. Mus. Natl. Hist. Nat. 4 sér. 14, 1992 (1993), section B, Adansonia, n. 3–4: 355–428 (partial revison).

Accepted Name : This is currently accepted.

Synonyms & Citations :

Description : Caulescent or acaulescent perennial herbs or subshrubs, often a part of the stem prostrate and rooting. Leaves equal or subequal, occasionally strongly dimorphic or one of the leaves suppressed, ovate to broadly ovate or elliptic, with (1–)2–4(–7) pairs of lateral primary veins departing at or above the blade base, glabrous or loosely pilose, petiolate, rarely subsessile. Inflorescence a terminal or axillary scorpioid cyme, variably contracted, or an umbel, rarely a simple dichasium or reduced to solitary flower. Flowers 4-merous, rarely 5-merous, with one or two stamen whorls. Hypanthium campanulate, cylindrical, occasionally cup-shaped or urceolate, with various kinds of hairs and emergences or glabrous; calyx lobes ligulate, triangular, or ovate to broadly obovate, usually sparsely hairy, often persistent in mature fruits. Petals elliptic or ovate to broadly obovate, often asymmetric, glabrous or ciliate, pink, purple or white. Stamens 4 or 8, rarely 10, isomorphic or rarely dimorphic, opening by a single pore, connective ventrally slightly lobed or unappendaged, dorsally with a tubercle, ridge, or spurs, or unappendaged. Ovary 4- or rarely 5-locular, crowned by denticulate or entire scales, or ovary unadorned, partially or fully adnate to the hypanthium, stamen pockets varying accordingly, placentae axillary. Fruit a capsule, quadrangular, 8- or rarely 10-ribbed, or campanulate, placentae distinctly stalked and often thready, column usually splitting distally into four horns. Seeds about 0.5–0.9 mm long, tuberculate, cuneate or oblong, never cochleate.

Fifty-six species from S China to the Malay Peninsula, Sumatra and Borneo; 4 species in Thailand.

The wider concept of the genus adopted here includes pentamerous groups such as Cyanandrium Stapf, Brittenia Cogn. ex Boerl., Enaulophyton Steenis, and Tigridiopalma C.Chen. The only difference between them and Phyllagathis is flower mery, which is an unstable character in Phyllagathis (and in Melastomataceae in general). Occasional pentamerous flowers occur, for example, in P. rotundifolia (below) and other species.