Eragrostis pilosa is an annual C4 grass (Watling and Press 1998) slender, short, densely tufted, 10-60 cm tall, erect, or bent only at base, often branching from lower nodes, sheaths shorter than internodes, top of sheath with long-hairy lobes, ligule a band of short hairs.
Leaves alternate, 0.1-0.3 cm wide.
Flower spikelets about 0.1-0.2 cm wide, 5-17 flowered, glumes smooth, first glume to 0.8 cm, lemmas over 0.1 cm long; palea deciduous inflorescence 5-20 cm long, diffuse, with lowest branches 2 or more per node, bearing spikelets only down to two thirds their length; July-Oct.
Wetland status: FACU.
Frequency in NYC: Very infrequent.
Habitat: open sites, roadsides, vacant lots.
Notes: Host to the root hemi-parasite Striga hermonthica, giant witchweed (Watling and Press 1998; USDA, NRCS 2010).