22. Gutierrezia Lag. (snakeweed)
(Lane, 1985)
About 28
species, North America, South America.
Lane (1982)
established the modern classification of Gutierrezia and its relatives,
recognizing several segregate genera that are widely accepted today and
transferring a number of species between genera. For example, the sole native
species of Gutierrezia treated by Steyermark (1963) is now considered
part of the small, closely related genus, Amphiachyris. Suh and Simpson
(1990) confirmed most of Lane’s conclusions using molecular data.