Neostapfia is a genus of endemic Californian bunchgrasses, in the Chloridoideae subfamily of the Poaceae (grass) family. The only known species is Neostapfia colusana, with the common name Colusa grass.
Neostapfia colusana is endemic to the Central Valley of California, in the northern section's Sacramento Valley and in the southern section's San Joaquin Valley. The bunchgrass grows in vernal pools, which are seasonal shallow freshwater ponds.
It is native to the Central Valley counties of Glenn, Colusa, Yolo, Solano, Stanislaus, and Merced.
This rare grass is a federally listed threatened species in the United States.
Neostapfia colusana is a clumping bunchgrass with distinctive cylindrical inflorescences covered in flat spikelets.
The inflorescences are said to resemble tiny ears of corn. They fruit in grains covered in a gluey secretion, and when a plant is mature each clump becomes brown and sticky with the exudate.
The genus was named for the botanist Otto Stapf.
The plant is limited to vernal pool habitats, a type of ecosystem which is increasingly rare as Central Valley land is consumed by development and agriculture, and damaged by flood control regimes and other alterations of hydrology.