Cenchrus palmeri

A grass of the Sonoran Desert with unpleasant spines, even for Cenchrus. Readily identifiable by its blackish inflorescences and swollen sheaths. Occurring in Baja California and adjacent Sonora, questionably in Arizona (the Cabeza Prieta NWR lists the species as present, but otherwise I can find no reference to this species in the US).

Plant habit about 10 miles west of Bahia de Los Angeles, 10/21/06.

Inflorescences about 10 miles west of Bahia de Los Angeles, 10/21/06.

A flowering stem, showing swollen sheaths, west of Bahia de Los Angeles, 10/21/06.