Sporobolus nealleyi

Common names: Gypgrass
Treatment appears in FNA Volume 25. Treatment on page 131.

Plants perennial; cespitose, bases hard and knotty, not rhizomatous. Culms 10-50(60) cm tall, 0.7-1.2 mm thick. Sheaths rounded below, occasionally glabrous, usually villous to tomentose along the margins and back, with soft, kinky hairs to 4 mm; ligules 0.2-0.4 mm; blades (0.6)1.5-6(7) cm long, 1-1.5 mm wide, involute, stiff, spreading at right angles to the culm, glabrous abaxially, scabridulous adaxially, margins smooth. Panicles 3-10 cm long, (0.3)1-5(6) cm wide, longer than wide, ultimately open, subovate, lower portion often included in the uppermost sheath; lower nodes with 1-2 branches; primary branches 0.5-5 cm, appressed or spreading to 90° from the rachis; secondary branches appressed or spreading, without spikelets on the lower 1/8 – 1/4; pedicels 0.2-2 mm, appressed or spreading. Spikelets 1.4-2.1 mm, purplish. Glumes unequal, linear-lanceolate to ovate, membranous; lower glumes 0.5-1.1 mm; upper glumes 1.3-2 mm, from slightly shorter than to subequal to the florets; lemmas 1.4-2.1 mm, ovate, membranous, glabrous, acute; paleas 1.4-2.1 mm, ovate, membranous; anthers 0.7-1 mm, purplish. Fruits 0.7-1 mm, orangish to whitish. 2n = 40.


Maine, Colo., N.Mex., Tex., Ariz., Nev.


Sporobolus nealleyi grows in sandy and gravelly soils, usually in those derived from gypsum, or near alkaline habitats associated with desert grasslands. It is known only from the southwestern United States, where it grows at 700-3000 m.

Selected References


Lower Taxa