Heterosperma pinnatum

A Bidens-like annual, differing from that genus in having all achenes but the central unawned, and in having the marginal achenes purplish and tuberculate.

Pseudanthia, Aguirre Springs on the northeastern side of the Organ Mts., 2 Oct 2006.

Pseudanthium with mature achenes at Aguirre Springs, 2 Oct 2006.

Achenes, Aguirre Springs, 2 Oct 2006.