Identity of Schizachyrium sulcatum and S. brevifolium (Poaceae: Andropogoneae)

Schizachyrium sulcatum, distributed in Brazil, Bolivia and Colombia, is described, illustrated, and reported for the first time from Peru and Venezuela. Synonymy, geographical distribution, ecology, and a list of representative specimens examined are provided. Characters of taxonomic value are established in order to differentiate this species from S. brevifolium. A comparative study based on morphology, leaf anatomy, and micromorphological features of the spikelets and leaf blade are included. The multivariate analysis based on morphological variables allows S. sulcatum to be distinguished clearly from S. brevifolium.