Sourgrass

Digitaria insularis, known as sourgrass or West Indian crabgrass, is a coarse tufted perennial grass native to tropical America and now a widespread weed across the warmer parts of the world. It forms dense tussocks 50-150 cm tall arising from a short, knotty, scaly rhizome covered in persistent leaf bases. The flat, linear leaf blades are 15-50 cm long and 6-15 mm wide, light green to slightly glaucous, with rough margins and a sparsely hairy upper surface near the base; ligules are short and membranous. The terminal inflorescence is an elongated, narrowly oblong, silver-bronze panicle 15-30 cm long composed of numerous slender, ascending racemes 6-15 cm long. The spikelets are paired or in threes along the racemes, narrowly lanceolate, 4-5 mm long, and clothed in long silky pale brown hairs that give the panicle its plumose appearance. Flowering occurs through the warm season. It thrives on disturbed ground, pastures, plantations, and roadsides.