Northern Prairie Wildlife Research Center
Aquatic and Wetland Vascular Plants of the Northern Great Plains
Poa L. -- Bluegrass
Tufted or rhizomatous perennials (those included here) of short to moderate
stature, green or glaucous; culms erect to decumbent, hollow, sometimes
compressed. Leaves mostly near the base, the blades flat to folded, the
margins and midrib converging to a blunt, keeled leaf tip resembling the prow
of a boat; sheaths partly closed, rounded or keeled; ligules membranous.
Inflorescence an open to narrowly contracted panicle of small, mostly
2- to 8-flowered spikelets. Spikelets disarticulating above the glumes
and between the florets; glumes subequal or the second a little longer
than the first, acute; first glume 1- to 3-nerved; second glume 3-nerved; lemmas
acute to blunt-tipped, reduced in size upward in the spikelet, faintly 5-nerved
or appearing 3-nerved, with the intermediate nerves very obscure or obsolete,
keeled or rounded on the back, often with a tuft of cobwebby hairs at the base,
this sometimes scant, otherwise glabrous, scabrous or pubescent mainly on the
nerves, sometimes pubescent or scabrous between the nerves as well; palea
nearly as long as the lemma.
||Culms strongly compressed, 2-edged; sheaths keeled.
||Culms round to slightly compressed, not 2-edged;
||Lemmas with a tuft of cobwebby hairs at the base,
this sometimes scant; foliage green.
||Lemmas lacking a tuft of cobwebby hairs at the
base, pubescent only on the keel and lateral nerves and sometimes
between the nerves on the lower back; foliage glaucous.
||Plants tufted, sometimes stoloniferous, lacking
rhizomes; panicle diffuse and open (contracted when young), mostly
8-30 cm long.
||Plants extensively rhizomatous; panicle more compact,
mostly 3-13 cm long.
||Lemmas pubescent on the keel and on the marginal
nerves toward the base, the intermediate nerves very fiant to obsolete.
||Lemmas pubescent on the keel only, not on the
marginal nerves, the intermediate nerves prominent.
63. Poaceae, the Grass Family
23. Poa L. -- Bluegrass
- 1. Poa arida Vasey -- Plains bluegrass
- 2. Poa compressa L. -- Canada bluegrass
- 3. Poa palustris L. -- Fowl bluegrass
- 4. Poa pratensis L. -- Kentucky bluegrass
- 5. Poa trivialis L. -- Rough bluegrass
Return to Family -- Poaceae - The Grass Family
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