Checklist of the family Poaceae from Colombia

Abstract

This contribution introduces an inventory of the species of Poaceae from Colombia, and an analysis of the species diversity according to the natural regions of Colombia, the altitudinal gradients, annual rainfall and systematic distribution. The inventory was based on about 5800 vouchers collected
throughout 96 fieldtrips along the 10 greatest natural regions of Colombia (Amazon, Andes, Caribbean, Caribbean Islands, Chocó Biogeográfico, Guayana, Orinoquia, Sierra Nevada de Santa Marta, Cauca valley, and Magdalena valley), on the study of vouchers of different herbaria with important collections for the flora of Colombia (CAUP, COAH, COL, CUVC, CHOCO, HFAB, HUA, HUQ, JAUM, MEDEL, MEXU, MO, NY, PSO, RSA, SI, UDBC, UIS, US, VALLE, and VEN), and on an exhaustive bibliographic research. Poaceae is represented in Colombia by 840 species and 173 genera. There are 74 species and one genus (Agrostopoa) endemic to Colombia. On the other hand, there
are 83 species introduced and naturalized, and 50 introduced and cultivated. The richest genera are Paspalum (89 especies), Panicum (42), Festuca (36), Eragrostis (29), Calamagrostis (25), Chusquea (25), Digitaria (24), Axonopus (21), Setaria (20), Cenchrus (18), Poa (17), Muhlenbergia (16), Andropogon (15), Aristida (15), Agrostis (14), Lasiacis (12), Urochloa (12), Pariana (11), Sporobolus (11), Arthrostylidium (10), Cortaderia (10), Nassella (10), Neurolepis (10), and Schizachyrium (10). As partial results of this research, 10 new records were described for the colombian territory. The most diverse Colombian regions are Andes, Orinoquia, Caribbean, and Guayana, with 583, 233, 186, and 179 species, respectively. The Andean Region shows the highest endemism values (57 species). The most diverse altitudinal gradient belongs to the lowlands (below 1200 m s.m.). In Colombia, the subfamilies of Poaceae show a distribution related to the altitude above the sea level and with the rainfall patterns. Thus the Panicoideae are more diverse in the wet lowlands and wet subandean areas, the Pooideae are more diverse in the high Andes (páramos), the Chloridoideae in dry areas, the herbaceous bamboos in the Amazon Region, and the woody bamboos in the Andean Region. The grasses constitute the sixth richest family in the Colombian flora, following the Orchidaceae, Asteraceae, Rubiaceae, Fabaceae, and Melastomataceae.