Publication: Watsonia 4(1): 47-48. 1957.
Origin:
Herbarium search: CPNWH
Notes: From JPM it appears that this species is endemic to CA. If occurring in WA it should be considered introduced. Howell made a collection of this species in 1882 near The Dalles in Oregon, and Suksdorf made a collection in the Portland area in 1916. Without evidence to the contrary, these populations are considered introduced to these localities. Creso includes G. tricornutum in her 1984 flora of western Washington and describes it as rare in waste places and fields. In the absence of specimens indicating its presence here in WA, we are considering G. tricornutum to be excluded from the flora at this time.
Last updated 2/29/2012 by David Giblin.