Image of Cosmos palmeri Robinson

Description:

on graded rubble of old roadside pullout in white volcanic tuff. This species is largely distinguished with difficulty from C. pringlei by a 2 cm difference in maximum width of the flowering heads which make photo determination impossible and pressed specimen difficult, without careful in-field measurements of live mature heads. In most cases I have placed these similar plants under C. palmer, the slightly smaller and more common of the two species.