Flora of the Hawaiian Islands
Monocotyledon Literature for Setaria verticillata
Lorence & Wagner, 2020.
   Poaceae -- The Grass Family Bibliography
      Setaria verticillata

Common name(s): bristlegrass, foxtail, bristlt foxtail, mau`u pilipili
General Information
DistributionNative to Europe, now widely naturalized.In the Hawaiian Islands, naturalized on Kure, Midway, Pearl and Hermes, French Frigate Shoals, Nihoa, Ni`ihau, Kaua`i, O`ahu, Moloka`i, Lana`i, Maui, Kaho`olawe, Hawai`i.

Poaceae - Setaria verticillata

Tufted annual; culms (2‒)3‒10 dm tall, often geniculate and branching at proximal nodes, glabrous except above near the panicles.
Leaves with sheath compressed-keeled, glabrous, distal margin ciliate; ligule ciliate, 0.7‒2 mm long; blade flat, 5‒20 cm long, 5‒10(‒18) mm wide, glabrous to scaberulous, sometimes sparsely pilose, margin scabrous.
Inflorescences paniculate, yellowish green to purple tinged, densely flowered, cylindrical, (2‒)4‒10(‒15) cm long, axis densely retrorsely hispidulous, primary branches short, whorled. Spikelets several to numerous per branch, subtended by 1‒4 bristles, bristles 2‒4.5(‒6) mm long, retrorsely scabrous; glumes unequal, first glume broadly ovate, 0.5‒0.7(‒1.2) mm long, ca. ⅓ as long as the spikelet, 1(‒3)-veined, apex obtuse, sometimes mucronate, second glume ovate, 1.6‒2 mm long, slightly shorter than first lemma, 5‒7-veined, apex rounded; first lemma 1.5‒2.4 mm long, 7-veined, apex rounded; first palea small, membranous; second lemma ovate, 1.8‒2.3 mm long, weakly 3-veined, finely transverse rugose; second palea similar in texture to second lemma.
Caryopses pale brown, broadly ovoid, slightly dorsiventrally compressed, 1.2‒1.5 mm long.
2n = 18, 20, 36, 54.
Nancy Khan