Eriastrum densifolium ssp. sanctorum

Eriastrum densivolium ssp. sanctorum is endemic to the Santa Ana River drainage of San Bernardino, Riverside and Orange Counties. Extirpated in Orange County, the beautiful perennial with large lavender flowers is known from several fragmented, damaged occurrences. Intensive use of the flood plain margins has resulted in alteration of habitat and habitat that is totally unsuitable. The Santa Ana River woollystar is also threatened by development, sand and gravel mining, flood control projects, non-native plant competition, intensive grazing, and farming. There are no protected EO's to speak of. The overall trend is very much downhill.

Endemic to the Santa Ana River drainage of San Bernardino, Riverside, and Orange counties (Zembal and Kramer 1985). Extirpated in Orange County (Skinner 1997). Declining in the other counties with many historic and extirpated EO's. Measured range extent of extant occurrences is 206 sq km.

23 known EO's (1/4 mi separation distance) but at least 5 extirpated and 7 historic. Only 1 large population.

Threatened by development, sand and gravel mining, flood control projects, and non-native plants (Skinner 1997). Intensive use of the flood plain margins resulting in altered to unsuitable habitat is a threat, as is intensive grazing and farming (Zembal and Kramer 1985). All of the preceding is still true in 2010 (CNDDB) but I would add OHVs, channelization and fragmentation. Flood control and urbanization remain the biggest threats to continuation of this species and its highly endangered habitat. The largest, most viable site, (EO 5) now has a dam (Seven Oaks Dam) above it which completely alters the hyrdology and succession cycle. It's probably only a matter of time until the lack of renewing floods takes its toll on the natural habitat of this floodplain species.