Culms 22-98 cm. Ligules 0.5-1.7 mm; blades 3-13(19) mm
wide, linear-lanceolate. Panicles 7.5-14(17) cm; lower branches
1-3.5 cm, appressed. Callus hairs 7-13 mm; glumes 2.4-4.5 mm;
lower lemmas 1-3.4 mm long, 0.5-1.1 mm wide; upper lemmas usually
absent, if present, about 1 mm long, 0.3 mm wide; stamens 1, bases of
the filaments dilated; anthers 1.4-2.8 mm; styles 1.1-4.7 mm;
stigmas 2.4-6.7 mm. 2n = unknown.
The current range of Imperata brasiliensis includes South America and
Central America, Mexico, and Cuba. It is now thought to be established in the
southeastern United States, although it is considered to be eliminated from
Florida (Hall 1978); collections of Imperata made there since 1970 having
proved to be I. cylindrica. The two
species differ in the number of their stamens and the frequent absence of the
lower lemma in I. brasiliensis.
Imperata brasiliensis is listed as a noxious weed by
the U.S. Department of Agriculture. Burning stimulates its flowering; consequently
many specimens have burned leaves.