Flora of the Hawaiian Islands
Monocotyledon Literature for Digitaria insularis
Wagner et al., 1990, 1999.
   Poaceae -- The Grass Family Bibliography
      Digitaria insularis

Common name(s): crabgrass, sourgrass
General Information
DistributionNative to the Neotropics, widely naturalized on Pacific islands and in Malesia.In the Hawaiian Islands, naturalized on Midway, Ni`ihau, Kaua`i, O`ahu, Moloka`i, Lana`i, Maui, Kaho`olawe, Hawai`i.

Densely tufted perennials; culms erect, 100-150 cm tall, base swollen, pubescent, hard, scaly.
Sheaths 12-15 cm long, much longer than internodes, usually papillose-pilose with hairs 5-10 mm long, or occasionally only papillose or glabrous, striate, compressed, keeled; ligule membranous, 5-10 mm long; blades lanceolate, 15-50 cm long, 10-15 mm wide, midrib conspicuous, upper surface scabrous, lower surface glabrous.
Inflorescences paniculate, 15-25 cm long, narrow, the branches slender, somewhat nodding, 7-15 cm long, silky pubescent; spikelets paired, narrowly elliptic, 3.5-4 mm long, densely yellowish brown silky pubescent; first glume ovate, scale-like, 0.5-1 mm long, second glume and first lemma subequal, 3-5-nerved, densely silky pubescent, the hairs exceeding the spikelets; second lemma reddish brown, lanceolate, 3-3.5 mm long, apex acuminate; palea similar to lemma.
Caryopsis whitish, compressed-ovoid, ca. 1.5 mm long, apex beaked.
2n = 36