Verbatim text: Ruffin, J. 1977. Palynological survey of the genera Amphiachyris, Amphipappus, Greenella, Gutierrezia, Gymnosperma, and Xanthocephalum (Compositae). Contr. Gray Herb. 207: 117–131.
Author: Ruffin, J.
Year: 1977
Title: Palynological survey of the genera Amphiachyris, Amphipappus, Greenella, Gutierrezia, Gymnosperma, and Xanthocephalum (Compositae)
Journal: Contr. Gray Herb
Volume: 207
Pages: 117–131