Rubiaceae of the New World

By Piero Delprete and Rocio Cortés
 

PERAMA Aublet
 

Photos needed

Synonyms: Buchia Kunth; Mattuschkaea Schreber, Mattuschea Batsch (orth. var.), Mattuschkea Kunth (orth. var.), Mattuskea Rafinesque (orth. var.), non Mattuschkia Gmelin

Erect or sprawling herbs; raphides present; axillary thorns absent. Stipules interpetiolar, free at base, reduced to a line between the leaves, persistent. Leaves in basal rosettes (opposite or ternate on extermemely reduced basal nodes), cauline, opposite or whorled, 3 or 4 per node, subsessil or sessil; blades ovate, narrowly ovate, very narrowly elliptic, elliptic, oblong, lanceolate or linear, planar, membranaceous, chartaceous, stiffly chartaceous or papyraceous; foliar pellucid glands absent; domatia absent. Inflorescence axillary, frondose, terminal, not frondose or frondose, spicate, simple, compound dichasia, terminating in spicate, globose to oblong heads or rarely in pauciflorous cymules. Flowers bisexual, protandrous. Calyx tube extremely reduced, with small lobes, persistent; lobes 3 to 5, narrowly triangular, lanceolate, subulate or linear, minute. Calycophylls absent. Corolla hypocrateriform, with a constriction below stamens attachments or narrowly infundibuliform, actinomorphic, white to cream-white, yellow, yellowish-white, pink or violet to purple or bluish-white to pale blue; tube externally glabrous, puberulent, strigose or villous; internally glabrous or pubescent at mouth; with a pubescent ring at orifice inside; orifice annular thickening absent; lobes 3 to 5, valvate, deltoid, narrowly triangular, ovate, suborbicular, margin entire, acute at apex. Stamens alternate to the corolla lobes, included or partially exserted (only tips exserted); anthers narrowly elliptic, round and lanate to barbate at base, dehiscing by longitudinal slits, dorsifixed near the base; filaments attached at the middle of the corolla tube or at the upper part of the corolla tube, free at base, filiform, short (anthers subsessil), equal, glabrous. Style exserted just beyond the corolla, filiform throughout, glabrous; lobes 2, ovate or elliptic. Ovary inferior, 2 to 4-locular, ovoid; placentation axile, placenta reduced, ovule apically inserted; ovules 1 per locule. Fruit capsular, circumcissile, chartaceous, multicostate, dehiscing tranversally, releasing the apical portion (operculum), the basal portion remaining attached to the peduncle. Seeds ascending, minute, ovoid to obovoid; wings absent.

Geographic distribution: West Indies, Magdalena-Llanos area, western Amazon Basin, Guayana Shield, central Amazon basin, eastern Amazon basin, northeastern Brazil, Brazilian Atlantic coast, Brazilian planalto and southern intertropical Andes.

Number of species: 13.

References: J. A. Steyermark & J. H. Kirkbride, Review of the genus Perama (Rubiaceae). Brittonia 29: 191–198. 1977; E. Robbrecht, Perama. On the delimitation of the Rubiaceae. Opera Bot. Belg. 6: 26. "1993" [1994].