Small-flowered Morning Glory [Convolvulus simulans Perry]
Listing CNPS List 4 R-E-D Code 1-2-2
State/Federal. Status -- None CONVOLVULACEAE Mar.-Jun.
Global Rank G2G3 State Rank S2S3
Distribution: San Diego County, Orange County, Riverside County, Los Angeles County, Kern County, Contra Costa County, Santa Barbara County, San Clemente Island, Santa Catalina Island, San Benito County, San Joaquin County, San Luis Obispo County, Stanislaus County; Baja California, Mexico
Habitat: This small annual grows on friable clay soils which are typically devoid of shrubs, in openings in chaparral, sage scrub, and grasslands. In San Diego County this species is often associated with Acanthomintha ilicifolia. It is also reported from ultramafic ridgelines.
Known Sites: This morning glory is found in San Diego County on a small mesa on the north slopes of Otay Valley east of Rock Mountain. It also occurs north of Palomar Airport Road east of the Carlsbad Raceway. Herbarium specimens were examined from the Sweetwater Valley, Vista, Black Canyon on Otay Ranch, and Casa de Oro near Spring Valley. North of Country Hills Lane and immediately north of Proctor Valley Road a population of exceptionally robust plants was observed in heavy clay soils which had been disced within the previous six months. Historical reports are from Rancho Santa Fe, Lemon Grove, Vista, and La Corta. Roberts reports this species from Orange County; Boyd reports its from the northwestern base of the Gavilan Hills and on the Gavilan Plateau. Smith reports this plant from the Santa Barbara region in Birabent Canyon south of Zaca Peak. Twisselmann reports it from Kern County in ultra-fine clay at Dry Bog Knoll at the head of Adobe Canyon in the Greenhorn foothills, and in San Luis Obispo County in the Pinole Hills in the Temblor Range near the Kern County line. Hoover reports this annual from a few locales in San Luis Obispo County from Cottonwood Pass to Estrella.
Twelve specimens are found at the herbarium of the San Diego Natural History Museum from Baja California, south to 30 42' North at Arroyo de la Escopeta where collected by Moran (SD 91602). Small-flowered Morning Glory grows adjacent to the vernal pools at Valle de las Palmas in an unusual mix of sealed pools and cracked clays.
Status: Small-flowered Morning Glory is declining in Southern California due to loss of habitat. The distinctive friable and very crumbly clay soils where this species is usually found are now quite rare in Southern California. Such areas are generally very small, often less than 1000 square feet in size, and have regularly been graded along with the coastal sage scrub within which they usually occur. All substantial populations in the southern portion of the State should be protected.
Copyright © May 1994 Craig H. Reiser.