Plants annual; glabrous or sparsely pilose, not producing juvenile floating leaves. Culms 10-30 cm, simple, ascending or decumbent, often geniculate, not breaking apart at the nodes. Leaves without ligules, with little or no distinction between sheath and blade. Inflorescences terminal, dense cylindrical spikes, usually completely exposed at maturity, spikelets spirally arranged, rachises often extending beyond the spikelets as a naked or scale-covered axis; disarticulation below the spikelets. Spikelets dorsally compressed, usually with 5 florets. Glumes absent; lemmas about 5 mm long, flabellate, to 3 mm wide distally, 7-11-veined, translucent between the veins, apices entire, ciliolate; paleas slightly shorter and much narrower than the lemmas, hyaline, 2-veined; lodicules 2, about 0.2 mm, truncate or slightly emarginate; anthers 3, exserted at anthesis, styles 2. Caryopses laterally compressed, obovoid, pericarp thick and covered with a viscid exudate, obscuring the embryo; epiblast present. x = 10. Named for Otto Stapf (1857-1933), a botanist at the Royal Botanic Gardens, Kew, England.

Neostapfia is a monotypic genus endemic to the Central Valley of California.

1.   Neostapfia colusana (Burtt Davy) Burtt Davy
Colusagrass

Plants cespitose, eventually forming rather large clumps, covered with prominent brown viscid glands at maturity. Culms 10-30 cm, simple, ascending or decumbent, often geniculate, not breaking apart at the nodes. Sheaths loosely enveloping the culms; blades 2-5 cm long, 5-12 mm wide. Spikes 2-8 cm long, 8-12 mm thick. Lower lemmas about 5 mm long, about 3 mm wide, 7-11-veined; anthers about 2.5 mm. Caryopses about 2.5 mm. 2n = 40.

Neostapfia colusana grows in vernal pools of Colusa, Merced, Solano, and Stanislaus counties, California, at elevations below 125 m. It is listed by the U.S. Fish and Wildlife Service as a threatened species because of its restricted habitat, much of which has been destroyed. The stout, cylindrical spikes emerging from the sheathing leaves resemble miniature ears of maize. This and the abundant viscid secretion make N. colusana a particularly distinctive species.