Eriochloa, commonly known as cupgrass, is a genus of warm-season annual and perennial grasses in the family Poaceae (order Poales). The genus comprises roughly 30 species distributed across tropical and subtropical regions of Africa, Asia, Australia, the Americas, and parts of temperate Eurasia including European Russia. Cupgrasses are characterized by their cup-shaped or disc-like structures (a hardened, bead-like callus) at the base of each spikelet, which is the morphological feature that gives the genus its common name and distinguishes it from closely related genera in the subfamily Panicoideae. The genus name is derived from the Greek words erion (wool) and chloa (grass), referring to the hairy or woolly spikelets found in many species. Several species are widespread weeds of agricultural fields and disturbed habitats, while others occupy native grasslands, savannas, and riparian corridors. Notable species include Eriochloa contracta (prairie cupgrass) of the central United States and Mexico, Eriochloa punctata (Louisiana cupgrass) of the Americas, Eriochloa polystachya (caribgrass) of Central America and the Caribbean, and Eriochloa villosa (hairy cupgrass) of eastern Asia. A number of taxa formerly placed in Eriochloa have been transferred to related genera including Urochloa, Brachiaria, and Panicum following molecular phylogenetic revisions.
Etymology
The name Eriochloa derives from the Greek erion (ἔριον, wool) and chloa (χλόα, grass or greenness), an allusion to the woolly or hairy spikelets characteristic of many species in the genus. The common name "cupgrass" refers to the distinctive cup-like or disc-shaped callus at the base of each spikelet.
Distribution
Eriochloa species are found across much of Africa, Asia, Australia, and the Americas, with a few species extending into European Russia and the Caucasus region. The genus is predominantly tropical and subtropical in distribution, with several species occurring in temperate grasslands and disturbed habitats of North America, including the central and southeastern United States.
Taxonomy Notes
Eriochloa belongs to the family Poaceae, order Poales, within the grass subfamily Panicoideae. Multiple species formerly placed in Eriochloa have been reassigned to related genera — including Ancistrachne, Axonopus, Brachiaria, Isachne, Panicum, Paspalum, Tricholaena, and Urochloa — following molecular and morphological revisions of the Paniceae tribe. GBIF recognizes the genus as accepted with between 6 and 15 species depending on the taxonomic backbone applied.
