Volume 10 NOVONNumber 4 N2000A Synopsis of the Genus Blakea (Melastomataceae) in Mexico and Central America Frank Almeda Department of Botany, California Academy of Sciences, Golden Gate Park, San Francisco, California 94118-4599, U.S.A.
[email protected] A regional synopsis of the genus Blak-ea is presented that recognizes 33 species in Mex-ico and Central America. This summary includes akey, distributional and phenological information,notes on morphological variation, and discussionsthat provide rationale for relegating six binomialsto synonymy. Descriptions and diagnoses are pre-sented for four new species of Blakea (B. colora-densis, B. darcyana, and B. perforata from Panama;and B. wilsoniorum from southern Costa Rica andPanama). Analysis of the type specimens and re-cently collected flowering material of Topobea stor-kii necessitates its transfer to Blakea. Three otherspecies (B. cuatrecasii, B. repens, and B. subcon-nata var. obtusa), all of which were previouslyknown from Andean South America, are reportedfrom Panama for the first time. Blakea, with approximately 100 species, is oneof two berry-fruited genera comprising the naturalneotropical tribe Blakeeae (Almeda, 1990). It isbest represented in wet montane regions fromsouthern Mexico and the West Indies to Bolivia andBrazil. Although northwestern South America is un-doubtedly the center of species richness for Blakea(Wurdack, 1973), southern Central America isclearly the area of focal importance for unusual di-versity in floral morphology. This floral diversity re-flects adaptations to a broad array of important pol-linators in the region, including rodents, buzzingbees, and hummingbirds (Almeda, 1990; Lumer,1981; Lumer & Schoer, 1986). For a woody genuswith showy, often spectacular, flowers, it is surpris-ing that Blakea has escaped the attention of seriousstudents until recently. The genus has not beentreated in its entirety since Cogniaux's (1891) fa-milial monograph. Even the most recent floristictreatments of the family Melastomataceae for theMesoamerican region appeared over 30 years ago(Gleason, 1958; Standley, 1924, 1938; Standley &Williams, 1963; Winkler, 1965) when many areaswere still little-explored and poorly known botani-cally. The account presented here is a precursor to the treatment that will appear in Flora Mesoamericana. Four new species and one new generic transfer are proposed in the context of a regional synopsis. This summary also includes a key to the 33 recognized species, distributional and phenological informa-tion, notes on variation, and discussions that pro-vide rationale for relegating previously recognized species to synonymy. TAXONOMIC TREATMENT Blakea P. Browne, Civ. Nat. Hist. Jamaica 323. 1756. TYPE: Blakea trinervia P. Browne. Trees, shrubs, or woody vines, often epiphyticwith glabrous or variously pubescent, terete orquadrate branchlets. Leaves thick and coriaceousor chartaceous, 3-to 5-nerved or -plinerved withthe transverse secondary veins (when evident)closely spaced, straight, and parallel. Flowers 6-merous, axillary, solitary or fascicled, typically pe-dunculate in the upper leaf axils and subtended bytwo pairs of decussate, free or variously fused, co-riaceous or foliaceous, sessile bracts inserted at thebase of the hypanthium. Hypanthia campanulate or NovoN 10: 299-319. 2000.
Localities extracted from OCR text.
BioStor
