Date of this Version
Blowout penstemon (Penstemon haydenii S. Wats.) was federally listed as an endangered species on 1 September 1987. This pap"!r describes the process by which species, emphasizing blowout penstemon, are listed. The five listing factors described in Section 4 of the Endangered Species Act, candidate species, and the listing process are discussed. The blowout penstemon listing process progressed as follows: 1) petition to list; 2) designation as Category 2 Candidate Species; 3) status survey; 4) designation as Category 1 Candidate Species; 5) proposed rule to list; and 6) the final listing rule. The primary reasons for listing were the stabilization of blowout complexes and the low probabilities of seed fertilization, maturation, dispersal, and seedling establishment.