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

Common name(s): bluegrass, annual bluegrass
General Information
DistributionNative to Europe.In the Hawaiian Islands, naturalized on Kure, Midway, Kaua`i, O`ahu, Moloka`i, Lana`i, Maui, Hawai`i.

Elevation0-3050 m
Bright green annuals; culms spreading or sometimes erect, rooting at nodes and forming mats, 0.3-2(-3.5) dm tall, strongly flattened.
Sheaths open ca. 1/2 their length, with overlapping margins; ligule 1-3 mm long, obtuse or truncate, often erose; blades lax, folded or flat, 1-10 cm long, 1-2.5(-3) mm wide, margins scaberulous, otherwise glabrous.
Panicles open, pyramidal, 1.5-3.5(-8) cm long, branches spreading, usually rigid; spikelets 3-6-flowered, (3-)4-5.5(-7) mm long, rachilla elongate; glumes glabrous, first glume narrowly lanceolate, 1.5-2.2 mm long, 1-nerved, apex acute, second glume oblanceolate to obovate, slightly longer than first glume, 1.8-2.7 mm long, 1-3-nerved, somewhat obtuse; lemmas 2.5-3.5 mm long, prominently 5-nerved, the nerves villous toward base, the margins scarious toward apex, pilose toward base; palea 1.5-2 mm long, 2-nerved, keeled, nerves villous, margins hyaline.
Caryopsis pale brown, ellipsoid, somewhat trigonal, ca. 1 mm long.
2n = 14, 24-26, 28, 52