PTERANDRA Adr. Juss. in A. St.-Hil., Fl. Bras. Merid. 3: 72. 1833 ['1832'].—Lectotype, designated by Cuatrecasas, 1958: P. pyroidea Adr. Juss.

Trees, shrubs, or subshrubs; vegetative hairs medifixed in most species, basifixed in one; stipules small (up to 8 mm long), intra- and epipetiolar, the members of a pair basally to completely connate, persistent; leaves often crowded at tips of branchlets, eglandular (except for tiny pellucid cells often visible abaxially in the lamina). Inflorescences lateral, a series of 2–6-flowered sessile or subsessile fascicles borne in the axils of leaves or bracts or above leaf scars; pedicels sessile, the floriferous bract and bracteoles clustered at the base of the pedicel, eglandular, persistent or deciduous. Sepals leaving outermost petal exposed in enlarging bud, all eglandular or all biglandular, the glands when present borne mostly below free part of sepals; corolla almost radially symmetrical, the posterior petal only slightly larger than the lateral 4 and with a slightly thicker claw; petals white or greenish yellow or green, becoming yellowish in age, or pink, abaxially sparsely to densely hairy, often persistent in fruit, erose or subentire, commonly with few to many pellucid cells visible abaxially; androecium radially symmetrical; stamens 10, all fertile; filaments distinct, alike or longer opposite petals than opposite sepals, mostly glabrous except for hairs at adaxial base (adaxially hirsute in one species); anthers alike, glabrous, the outer locules bearing introrse longitudinal wings, the connective exceeding the locules at apex; pollen radially symmetrical, 3 (4)-colporate; receptacle bearing straight basifixed hairs on both sides of the androecium; gynoecium radially symmetrical; ovary with the 3 carpels distinct, all fertile; styles 3, attached subapically, slender and subulate with minute apical stigmas. Fruit dry, comprising 3 cocci borne on a low torus; cocci subspheroidal, unwinged, smooth, indehiscent, with a papery exocarp and a moderately thick, corneous but not bony endocarp. Chromosome number: n = 12 (W. R. Anderson, 1993a).

Fifteen neotropical species, all but two native to South America, principally Colombia, Venezuela, and Brazil; the exceptions are from Panama. Most grow in wet or mesic forests, but a few (including the only species that is widespread and well collected, P. pyroidea) inhabit campos, cerrados, or savannas. [map] — Regional key to genera: Central America.

In its winged anthers and smooth cocci this genus resembles its sister, Acmanthera, but whereas Acmanthera has an elongated pseudoracemose inflorescence, Pterandra is notable for the reduction of its inflorescences to few-flowered sessile or subsessile fascicles, giving it a characteristic appearance unlike any other genus in the family.

References: C. Anderson, 1997b (revision [pdf]), and 2005c (new species [pdf]).

Etymology: The name Pterandra comes from the Greek words for wing (pterys) and man (andros), referring to the wings on the locules of the anthers.

Uses: None known.

Photos: view all; P. arborea, P. isthmica, P. pyroidea

Drawings: view all; (that most representative of the genus in boldface): P. andersonii,
P. colombiana
, P. hatschbachii, P. hirsuta, P. mcphersonii,
P. pyroidea, P. sericea, P. viridiflora

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