3. Lipocarpha micrantha (Vahl) G.C. Tucker

Pl. 78 h–j; Map 298

Scirpus micranthus Vahl

Hemicarpha micrantha (Vahl) Britton

Spikelet scales 0.8–1.1 mm long, obovate, brown to reddish brown, the tip tapered to a short point, this spreading to recurved, but much shorter than the main body of the scale. “Perianth” scales absent or 0.1–0.3 mm long, much shorter than the fruits, linear or narrowly 2-lobed.

Scattered mostly in the southern half of the state and along the floodplains of the Missouri and Mississippi Rivers (U.S. and adjacent Canada south to South America; Caribbean Islands, Africa). Mudflats and sand- or gravel bars of streams, rivers, and canals, muddy margins of ponds, lakes, and sloughs, moist depressions of acidic glades, and moist, sandy, disturbed areas.

This is by far the commonest species of Lipocarpha in the state, and it occurs in the greatest variety of habitats. In addition to the spikelet characters discussed above, the achenes of L. micrantha differ from those of the other two species in being less strongly obovate in outline and less angular and more turgid in cross-section, with the surface more finely pebbled and often somewhat lighter in color.