Small-flowered Microseris [Microseris douglasii (DC) Sch.-Bip ssp. platycarpha (Gray) Chambers]
List: CNPS List 4 R-E-D Code 1-2-2
State/Federal. Status -- None ASTERACEAE Mar.-May
Global Rank G4T2T3 State Rank S2S3
Distribution: San Diego County, Orange County, Los Angeles County, Riverside County, San Clemente Island, Santa Catalina Island; Baja California, Mexico
Habitat: This nondescript annual is typically found on clay lenses in perennial grasslands, on the periphery of vernal pools, or in broad openings in sage scrub.
Known Sites: Small-flowered Microseris grows near the vernal pool complex north of Peñasquitos Canyon and west of Black Mountain Road (north of Dormouse Road). It was seen in limited numbers on north-facing slopes overlooking Otay Lakes Road near Bonita, south of Camino Del Cerro Grande Road. Herbarium specimens examined were from Camp Kearny, near Ramona, Otay Mesa, Point Loma, Rancho Santa Fe, National City, San Diego, Sweetwater Valley, Mission Grade in Mission Hills, Point Loma, and Miramar; also San Clemente Island and Santa Catalina Island. Reported sites include San Luis Rey, and Mission Valley. A number of these historical sites may be extirpated, as this species tends to grow in flatlands which have been extensively developed in the region. Lathrop and Thorne report this species as infrequent on the Santa Rosa Plateau of western Riverside County. Roberts reports this species for Orange County.
Six voucher specimens from Baja California are found at the herbarium at the San Diego Natural History Museum; south to 30 39' North where collected by Moran (SD 91178) on a ridge 7 miles northeast of Las Escobas.
Status: This annual is presumed to be severely declining in Southern California owing to urban development. Small-flowered Microseris is extremely difficult to census for except during its short flowering season in early and mid spring. Until more collection information can be gathered, all substantial sites are recommended for protection, and substantial portions of all smaller populations should be placed into biological open space. It is not common in grassy areas of coastal San Diego County as reported in the 1994 CNPS Inventory of Rare and Endangered Vascular Plants; this species is in fact quite uncommon in this region.
Copyright © May 1994 Craig H. Reiser.