Jaragua grass

Hyparrhenia rufa, the jaragua grass or thatching grass, is a robust tufted perennial bunchgrass of the family Poaceae growing 0.6-2.5 m tall and native to tropical and subtropical Africa from Senegal and Ethiopia south to South Africa, and widely naturalized throughout the neotropics as a forage and invasive species. The plant forms dense erect clumps from short knotty rhizomes. Culms are slender, smooth, hollow, sparsely branched above and bear glabrous to slightly pubescent leaf sheaths. The flat or folded linear leaf blades are 20-60 cm long and 3-8 mm wide, scabrous on the margins, bluish-green and often turning purplish or reddish at maturity. The inflorescence is a loose terminal false panicle 20-60 cm long composed of many paired racemes subtended by reddish-brown spathes; each pair of racemes consists of two short flat hairy spikes 1.5-3 cm long bearing sessile and pedicelled spikelets. The sessile spikelets are awned, with a strongly bent dark brown geniculate awn 2-3 cm long that twists hygroscopically, while the pedicelled spikelets are awnless. The whole inflorescence ripens to a striking rufous-brown colour. It dominates seasonally dry tropical savannas, pastures and disturbed roadsides.