puffsheath dropseed
Sporobolus neglectus Nash

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planthabitliguleinflorescencespikelet, floretillustration

Puffsheath dropseed is widespread in North America but seems to be most common in the Midwest and is considered to be rare in the Northeast. This species is found throughout Iowa, mainly in disturbed areas or dry, sterile soils, but is not recorded from a number of eastern counties, perhaps because it can be inconspicuous. Puffsheath dropseed is very similar to poverty grass (Sporobolus vaginiflorus), but can be distinguished by its slightly more inflated leaf sheaths, more ovate, shorter spikelets, and glabrous lemmas. In both species, the flowering heads are usually mostly or completely enclosed in the leaf sheaths. This species flowers from August to October in Iowa.

Etymology: Sporobolus from the Greek sporo = seed and ballein = to throw, referring to the free seeds in many species of this genus that are sometimes forcibly ejected when the usually mucilaginous fruit wall dries; neglectus from the Latin for neglected, perhaps referring to the delicate nature of the plant that allows it to be overlooked.


Plants annual, delicate, tufted. Culms (10) 15-55 cm tall. Leaves with the sheaths open, glabrous; ligules a line of hairs 0.1-0.3 mm long; blades 1.5-14 cm long, 1.2-2 mm wide, flat to folded, the lower surface glabrous, the upper surface minutely roughened. Flowering heads terminal and axillary, 1.5-5.5 cm long, 0.2-0.5 cm wide, narrow, usually enclosed within the somewhat inflated sheaths of the leaves but often the terminal flowering heads fully exserted. Spikelets 2.5-2.8 mm long, purplish, laterally compressed; glumes equal, membranous, 1-nerved, 1.3-2.3 mm long; lemmas 2-2.5 mm long,1-nerved, membranous, acute; paleas equaling the lemmas, 2-nerved, membranous. Fruits 1.2-1.8 mm long, obovoid. Chromosome number 2n = 72.



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