San Diego Barrel Cactus [Ferocactus viridescens (T. & G.) Britton & Rose]
Listing CNPS List 2 R-E-D Code 1-3-1
State/Federal. Status -- /C2 CACTACEAE May-Jun.
Global Rank G4 State Rank S3.1
Distribution: Coastal San Diego County; Baja California, Mexico
Habitat: The optimal habitat for this cactus appears to be Diegan Sage Scrub hillsides; often at the crest of slopes and growing in cobbles. It occasionally is found on the periphery of vernal pools and mima mound topography at Otay Mesa, sometimes in considerable numbers. This presumably more mesic habitat (Stockpen gravelly clay loams) is unlike the very xeric situations where it is typically found. This barrel cactus utilizes a number of other soil types such as San Miguel-Exchequer rocky silt loams and Redding gravelly loams.
Known Sites: San Diego Barrel Cactus occurs at numerous locales throughout the coastal region. Its highest densities are found on Otay Mesa with particularly large populations northeast of Brown Field and at the east end of Wruck Canyon. Other sites with vigorous populations include the Naval Subase at Point Loma, Miramar Airfield lands, the east end of Otay Valley, and the flanks of Mother Miguel Mountain east of Bonita. Isolated plants grow in canyons on Otay Mountain. It is readily found in the Tijuana Hills and Torrey Pines State Park. San Diego Barrel Cactus becomes increasingly rare as one travels northward; a small colony is found on a north-facing slope near the mouth of the San Luis Rey River. Moving inland, populations also dwindle with most sites north of Interstate 8 occurring west of Interstate 15; isolated colonies occur east of here in the hills south of Poway, south to Mission Trails Regional Park. Locales with over 100 individuals should be considered major sites. One eastern report is from an isolated hill adjacent to the San Diego River in Lakeside. Limited populations have been observed at sites near Clemson Drive on Mount Soledad, on the south-facing slopes of Poggi Canyon, in the sage scrub north of Otay Lakes, near Tim Street in Bonita, on the south-facing slopes of Rock Mountain in Otay Valley, near Lynndale Lane east of Interstate 805 in Chula Vista, near Lake Murray Dam, on the southwest flanks of Black Mountain near Rancho Penasquitos, east of Interstate 15 near Mercy Road, near the southern terminus of Dillon Road on Otay Mesa, on the southern boundary of the Miramar landfill in San Clemente Canyon, near the junction of Miramar Road and Interstate 805, near El Nido Road in Rancho Santa Fe, in Lux Canyon in Encinitas, close to Gatchell Road on the southern tip of Point Loma, on Dictionary Hill in Spring Valley near Grand Street, in La Zanja Canyon, and on the north-facing bluffs overlooking the Otay River near Bayer Boulevard. Old biological survey reports note sites below the Sweetwater Dam, in Carroll Canyon south of El Camino Memorial Park, at Yale Avenue near Lemon Grove west of Highway 94, on Peñasquitos Ranch east of Del Mar Mesa, south of Artesian Road and north of Lusardi Creek near Camino Juan Arturo, in Telegraph Canyon, near La Manda and Pomerado Road in Poway, west of Pomerado Road and north of the State Highway S-6 right-of-way, at the terminus of Adams Avenue overlooking Mission Valley, southwest of Sienna Canyon Drive in Encinitas, west of Olivenhain Cemetery, north of the San Dieguito River near Las Colinas Road, between La Glorieta Road and Rancho Santa Fe Road, near El Apajo Road just south and beyond the Rancho San Dieguito Boundary, in the hills south of San Dieguito Road and the Fairbanks Ranch Golf Course, at the northeastern corner of the El Camino Memorial Park, 0.5 mile north of La Zanja Canyon and 1 mile east of the San Dieguito Valley on Fairbanks Ranch, north of Via de La Valle near Andres Drive, south of Del Mar Heights Road and east of El Camino Real in North City West, on the Scripps Ranch near Miramar Reservoir, near Traubert Ranch Road in Encinitas, and in Moody Canyon on Otay Mesa. Numerous Data Base reports note sites on the south slopes of Long Canyon near Bonita, east of Sycamore Canyon and south of Clark Canyon 3 miles southwest of San Vicente Reservoir, 1 mile west of San Diego State University northwest of Fairmont Drive and Montezuma Road and southwest of Yerba Santa Park, on a mesa north of Shepherd Canyon and the north end of Santo Road, in Oak Canyon 0.5 mile north of Old Mission Dam, the ridge on the east side of Tecolote Canyon in Linda Vista just west of Goodwin Street, Mission Hills, just east of the Easter Cross on Soledad Mountain, ridge east of Pomerado Road between Vaughan and Shallman Drives 1.5 miles north of Poway Road, 0.5 mile south southeast of the junction of Poway Road and Pomerado Road, numerous locales southeast of Valley School in Poway, several locales southwest of Garden Road School in Poway, 0.25 mile west of Interstate 805 and 0.25 mile north of Eastgate Mall Road, bluff between Del Mar and Torrey Pines Park, the east face of Soledad Canyon 0.5 mile south of Los Peñasquitos Canyon, on Spooners Mesa in the Tijuana Hills, 2.4 miles south of Del Dios south of Lake Hodges, north side of Black Mountain Road 1.7 miles west of Junction of Highway 395, several locales on the 4-S Ranch south of Black Mountain Road and west of Rancho Bernardo, several locales near the confluence of San Dieguito River and Lusardi Creek east of Rancho Santa Fe, the upper part of Little Sycamore Canyon near the County landfill, the south side of Otay Valley east of Interstate 805, north and south sides of San Clemente Canyon east of Interstate 805, various locales in Rice Canyon in Chula Vista, La Mesa on the northwest side of Fletcher Parkway and Amaya Drive, Kuebler Ranch on eastern Otay Mesa and east onto Otay Mountain, southeast of Lower Otay Reservoir, east of Rancho Los Peñasquitos Golf Course, south of Mira Mesa and south of Carroll Canyon west of Arjons Drive, east of Del Mar Heights 0.33 mile east of El Camino Real, near the intersection of Del Mar Heights Road and Dunham Way, a hillside east of Jamacha Boulevard north of the junction with Spring Glen Lane, north of Fletcher Parkway and east of Fanita Drive near La Mesa, east of the northernmost of the Santee Lakes, west of Chester Grade on Otay Mesa, at the end of Lymbrooken Lane south of Prospect Avenue in Santee, on a south-facing bank of Chollas Creek near Fairmont Avenue, various locales in and near Sycamore Canyon and Oak Canyon and Spring Canyon and San Clemente Canyon on Miramar Naval Air Station, northeast of junction of Friars Road and Interstate 15, near Kearney Villa Road and Interstate 15, near Interstate 15 and Clairemont Mesa Boulevard, Lopez Ridge 1 mile north of Mira Mesa Boulevard, Gonzales Canyon on the east side of old El Camino Real Road near Derby Downs Road, Wolf Canyon near Otay Valley, Salt Creek near Otay Valley, east of Buschalaugh Cove on Lower Otay Reservoir and locales near the dam, northwest of the intersection of Fury Lane and Sundown Lane in El Cajon area, Chollas Heights Naval Radio Station, scattered locales in Proctor Valley, several locales near Upper Otay Reservoir, various locales east of the Eucalyptus Hills on the Fanita Ranch, north of Carlton Hills near Santee, and numerous locales in the Black Mountain Ranch area near intersection of McGonigle Canyon Road and Black Mountain Road.
Twelve specimens are found in the San Diego Herbarium from Baja California; collected as far south as 30 North near Punta San Telmo by Moran (SD 59047). Limited Baja collections may reflect the difficulties in preparing herbarium specimens of this barrel cactus. It is locally common on the north coast of Baja California and occasionally inland such as in the hills overlooking Rodriguez Dam east of Tijuana, and about the vernal pool complex north of Cerro Bola near Valle de las Palmas. This barrel cactus regularly occurs in beach bluff sage scrub dominated by Bergerocactus emoryi such as found in the volcanic hills north of La Fonda, or on hillsides of predominantly Viguiera laciniata such as at Baja Del Mar.
Status: San Diego Barrel Cactus is declining, but still grows at many locales. Once very common along the coast, many small and mid-sized populations are routinely being impacted by grading for urban development. Particularly hard hit are the once vigorous colonies on Otay Mesa. Substantial portions of all sizeable populations should be protected.
Copyright © May 1994 Craig H. Reiser.