Sisyrinchium cernuum

Sisyrinchium powellii B. Warnock was once thought to be a narrow endemic restricted to the Davis Mountains of west Texas. Later, it was submerged as a synonym within the considerably more widespread Sisyrinchium cernuum (Bickn.) Kearney (e.g. see Jones et al., 1997; Kartesz, 1999).

When Sisyrinchium powellii was thought to be a narrow endemic (restricted to the Davis Mountains of west Texas), it was considered a species of conservation interest and had an appropriately high G rank. Later, Sisyrinchium powellii was submerged within the widespread Sisyrinchium cernuum, and the high global rank of the former somehow was inappropriately applied to the latter. The current interest in the status of this latter species is thus somewhat an accident of data management. McVaugh (1989) indicated that Sisyrinchium cernuum occupies a broad spectrum of habitats in its range from the southwestern United States through eight states in the northern half of Mexico. It seems clear that Sisyrinchium cernuum merits a global rank of G5.

Sisyrinchium cernuum is primarily Mexican in distribution, occurring in Aguascalientes, Chihuahua, Durango, Guanajuato, Jalisco, M?xico D.F., Sinaloa and Sonora (McVaugh, 1989; central BCD, 1997); the northern tip of its range includes the mountains of Arizona and Trans-Pecos Texas. In Texas it is known only from Mount Livermore in the Davis Mountains of Jeff Davis County; plants from that location were once treated as the separate species Sisyrinchium powellii, but that taxon is now considered a synonym (e.g. Kartesz, 1999).

No attempt has been made to collect occurrence information on this widespread species. Given its global abundance, it has never been tracked (monitored) by any Heritage program. Since it ranges latitudinally from 20oN to 32oN and occurs in a broad spectrum of habitats, hundreds or perhaps thousands of occurrences should be expected.

Threats to the globally common and widespread Sisyrinchium cernuum are unknown and perhaps non-existent.