A Taxonomic Revision of the Eastern North American and Eastern Asian Disjunct Genus Brachyelytrum (Poaceae): Evidence from Morphology, Phytogeography and AFLPs

Abstract

Abstract Morphological and phytogeographical data support the recognition of three distinct species in the genus Brachyelytrum: B. japonicum, B. erectum, and B. aristosum. Brachyelytrum japonicum is confined to eastern Asia and is characterized by narrow leaf blades (0.5–0.8 cm wide), long lower glumes (0.2–2.0 mm long), and long rachillas (6.8–8.8 mm long). Brachyelytrum erectum is distributed throughout much of the eastern United States, from northwestern Minnesota south to central Louisiana, east to northern Florida and north to northeastern New York. Brachyelytrum erectum is characterized by long hispid hairs (0.2–0.9 mm long) on the veins of the lemma, wide lemmas (0.8–1.8 mm wide), and a conspicuous lemma mid-vein. Brachyelytrum aristosum has a more northern distribution, occurring in southern Canada from southern Ontario to Newfoundland, the northern adjacent United States and through the Appalachian mountains to northwestern North Carolina. Brachyelytrum aristosum is characterized by short scaberu...