13.031   LIMNODEA L.H. Dewey

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Neil Snow

Plants annual; tufted. Culms to 60 cm, often prostrate and branching at the base, glabrous; internodes solid. Sheaths open or closed, rounded on the back, frequently hispid; auricles absent; ligules membranous, usually lacerate and minutely ciliate; blades flat, mostly ascending, glabrous or hispid abaxially and/or adaxially. Inflorescences panicles, loosely contracted; branches spikelet-bearing to the base or nearly so. Spikelets pedicellate, subterete, with 1 floret; rachillas prolonged as a slender bristle, glabrous; disarticulation below the glumes. Glumes equal, rigid, chartaceous, hispid or scabrous, veinless or obscurely 3-5-veined, acute, unawned; calluses blunt, glabrous; lemmas equaling the glumes, chartaceous, smooth, veinless or inconspicuously 3-veined, minutely bifid or acute, awned near the apices, awns exceeding the florets, geniculate near midlength, basal segment twisted; paleas shorter than the lemmas, veinless or the base 2-veined, hyaline; lodicules 2, glabrous, toothed or not toothed; anthers 3; ovaries glabrous. Caryopses about 2.5 mm, linear. x = 7. Name from Limnas, a similar Eurasian genus, and the Greek odes, like.

Limnodea is a monotypic genus of the southern United States and adjacent Mexico.

SELECTED REFERENCE Brandenburg, D.M. and J.W. Thieret. 2000. Cinna and Limnodea (Poaceae): Not congeneric. Sida 19:195-200.

1.   Limnodea arkansana (Nutt.) L.H. Dewey

Culms 15-60 cm. Ligules 1-2 mm; blades 3-12 cm long, 2-8 mm wide. Panicles 5-12 cm long, 1-5 cm wide, loose, mostly erect. Spikelets 3-4 mm; rachillas prolonged 0.3-0.9 mm. Glumes 3-4 mm; lemmas 3-4 mm, awns (5)8-14.5 mm; anthers 0.2-0.4 mm. 2n = 14.

Limnodea arkansana grows in dry, usually sandy soils of prairies, open woodlands, disturbed areas, and riverbanks. Along the Gulf coast, it grows on maritime shell mounds and middens and upper beaches where shells accumulate. It has also been found, as an introduction, around a wool-combing mill in Jamestown, South Carolina.