Southwestern Spiny Rush [Juncus acutus L. ssp. leopoldii (Parl.) Snog.]

Southwestern Spiny Rush [Juncus acutus L. ssp. leopoldii (Parl.) Snog.]

Listing CNPS List 4 R-E-D Code 1-2-1

State/Federal. Status -- None JUNCACEAE May-Jun.

Global Rank G5T5 State Rank S3?

Distribution: San Diego County, Los Angeles County, Santa Barbara County, Ventura County, Orange County, and San Luis Obispo County; Baja California, Mexico

Habitat: Coastal Salt Marsh at brackish locales, Alkaline Meadows, and Riparian Marshes are all utilized by this rush. At mid-elevations this species may occur in limited numbers along drainages with willow riparian vegetation or sycamore woodland. On the desert Spiny Rush may grow at palm oases. A variety of soil types are used including Tujunga sand and Riverwash. Wherever water can pond along substantial seasonal drainages, this rush has potential habitat. It usually drops out of the flora at moderate elevations.

Known Sites: This distinctive large bushy rush is common in marshes throughout coastal San Diego County. It is abundant in the San Diego River flood control channel west of Interstate 5. It is common in the Sweetwater River in Bonita, in the Otay River concentrated around old sand mining ponds, and in similar habitat on the San Diego River in Mission Gorge, on the San Dieguito River below Lake Hodges, and on the Otay River. It is sometimes found in vestigial dunes and marsh on the Silver Strand. This rush is frequently found on the eastern periphery of the coastal lagoons such as Agua Hedionda, San Dieguito, and San Elijo. It was seen at a palm oasis in the Coachella Valley in Riverside County and grows around similar springs in San Diego County on the Colorado Desert such as Mountain Palm Springs. Small populations can be found along Agua Hedionda Creek in Vista, in Little Hansen Creek near the Sweetwater Reservoir, near Moonlight Beach in Encinitas, in the drainages west of Black Mountain and Rancho Penasquitos, on Escondido Creek in Olivenhain, and to the east of this near Aliso Canyon Road. Herbarium specimens in San Diego include Otay Mountain, the Jamul Mountains, Cottonwood Creek, and Flynn Springs. It is readily seen growing in alkaline marshes paralleling Proctor Valley Road near Jamul. Also, it is locally common about Newport Back Bay in Orange County. This species is reported from Santa Catalina Island southeast to Sonora, Mexico. Reported by Roberts for Orange County at Bolsa Chica and Monarch Beach. Reported by Raven as frequent in seepages and by coastal marshes in the Santa Monica Mountains region. Smith reports this shrub at salt marshes in Carpenteria, Goleta, and Gaviota; and inland at Little Caliente and Agua Caliente springs. Reported by Hoover from Morro Bay, Avila, and Pismo Beach.

Thirty-six specimens for Baja California are found at the San Diego Natural History Museum's herbarium; south to 23 24' north where collected by Mudie (SD 93683) at the beach near San Pedrito. Southwestern Spiny Rush is common in a drainage several miles east of Rodriguez Dam in Baja California, on the highway to Tecate. It is locally abundant near the mouth of Guadalupe Valley and occurs at a variety of other wetland locales in northern Baja California.

Status: Southwestern Spiny Rush populations in San Diego County are now stable despite several decades of losses associated with widespread regional reductions in wetlands. This species can be readily grown in suitable habitat.

Copyright May 1994 Craig H. Reiser.

Back to Craig H. Reiser's Rare Plants of San Diego County