Aquatic and Wetland Vascular Plants of the Northern Great Plains

63. Poaceae, the Grass Family

2. Agrostis L. -- Bentgrass

2. Agrostis hyemalis (Walt.) B.S.P. -- Ticklegrass

Tufted perennial with slender culms, erect to decumbent, 2-6 dm tall. Leaves mostly basal, the blades ascending to spreading, flat to involute, 0.5-2 mm wide, glabrous or scaberulous; sheaths glabrous, the ligule hyaline, rounded and usually erose, 1-2 mm long. Panicle open and diffuse, 8-25(35) cm long, the main branches rather lax, filiform and spreading, themselves branching and bearing spikelets only above the middle. Spikelets often purplish, (1.5)2-2.8(3) mm long; glumes lanceolate, acute to acuminate, 1.3-2.8 mm long; lemma 1.2-1.5 mm long; palea absent; anthers 0.2-0.5 mm long. Grain brown, narrowly ellipsoid, 1-1.2 mm long. Jun--Aug. Wet meadows, seepage areas, ditches, stream banks, shores and also in upland situations, often where alkaline; frequent; (Labr. to AK, s to FL and Mex.). A. scabra Willd.

Two intergrading varieties may be recognized in the region. The prevalent one, var. tenuis (Tuckerm.) Gl. (= A. scabra Willd.), has larger spikelets than the typical variety and can be distinguished by the first glume 2-2.8 mm long. Entering our range from the s is var. hyemalis which has the first glume 1.3-1.7 mm long. Var. hyemalis is frequent in NE to s and e SD. Intermediates not assignable to either variety are encountered in the range of var. hyemalis in our region.


Agrostis hyemalis (from Hitchcock 1950, as A. hiemalis).

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