Tecate Tarplant [Hemizonia floribunda Gray]
Listing CNPS List 1B R-E-D Code 2-2-2
State/Federal. Status -- /C2 ASTERACEAE Aug.-Oct.
Global Rank G3 State Rank S2.2
Distribution: San Diego County; Baja California, Mexico
Habitat: Sandy washes in the high desert are a typical locale for the Tecate Tarplant. Carrizo very gravelly loam is found in the broad wash west of Jacumba. This floodplain has deep sandy alluvium and limited shrub cover, allowing for the few, well adapted species to grow unencumbered by substantial vegetative competition.
Known Sites: Tecate Tarplant grows in a broad, sandy floodplain west of Jacumba. Old reports are from Tecate Junction, Boundary Creek, Potrero, Canyon City, Jewell Valley, Bankhead Springs, McCain Valley, 0.5 mile southeast of Tierra del Sol, and Hipass. Old biological survey reports note sites east of Tierra del Sol Road near the railroad right-of-way, at Bankhead Springs, 1 mile west of Potrero Valley Road near Highway 94, 0.25 mile north of the Mexican border east of Bankhead Springs and north of the San Diego Arizona Eastern railway line, near the junction of Highway 94 and Highway 188 at the Tecate Road turnoff, and between Interstate 8 and Highway 94 east of Boulevard. Data Base reports are from 1.25 miles north northeast of Potrero Peak and 0.3 mile southeast of Round Potrero Road, 1 mile northwest of Potrero Peak east of the south end of Coyote Holler Road, 0.1 mile north of Interstate 8 and 1.1 mile southeast of junction of Highway 1 and State Route 94, 0.75 mile southeast on Interstate 8 from its junction with State Route 94, the top of the grade between Dulzura and Cottonwood, near Live Oak Springs, in McCain Valley 0.2 mile south of the southern cattleguard for Lark Canyon Campground, both 0.1 mile south and 0.8 mile north of the northern cattleguard for Lark Canyon Campground, and 0.5 mile south of the junction of the junction of Lost Valley Road and McCain Valley Road.
Only six specimens are found from Baja California at the San Diego Natural History Museum's herbarium. It has been collected as far south as 31 5' North by Moran (SD 106365) at Rancho San Jose. All six collections occurred in sandy washes.
Status: Populations of Tecate Tarplant are stable in San Diego County, with little historical development/degradation of its sandy wash habitat. Principal impacts are from cattle grazing and general degradation of wash habitat by cattle herds. All populations should be protected.
Copyright © May 1994 Craig H. Reiser.