Also, new reports are from the southeastern flank of San Miguel Mountain. An older biological survey report where possibly no longer extant is from the southern terminus of El Rancho Grande Road in Bonita. Data Base reports are all from locales near the above sites, from between Otay Lakes Road and Corral Canyon Road in the Long Canyon drainage, east of Otay Mesa on the western edge of Otay Mountain about 5 miles east southeast of Brown Field, east of Dennery Canyon on Otay Mesa, west of the junction of Siempre Vista Road and La Media Road on Otay Mesa, just east of the Chester Grade on northern Otay Mesa, both in Wolf Canyon and near Rock Mountain near Otay Valley, 0.7 mile south of the Lower Otay Reservoir, the southern end of Salt Creek 0.5 mile west of Lower Otay Reservoir, 0.5 mile north and slightly west of Upper Otay Reservoir, and Wildman's Canyon near Mother Miguel Mountain. It has also been collected on the south side of Guadalupe Valley. It is strongly recommended the State of California take stronger action to protect this species from urban pressures.
More taxonomic work is needed.
It is uncommon in northern San Diego County south to near Barham Road in San Marcos. H. conjugens is restricted to cracking clay soils generally devoid of woody shrubs. Taking into account that population numbers at single sites may be very high even within relatively confined areas, it is recommended that substantial portions of all populations of Otay Tarplant should be protected and placed into dedicated biological open space. Copyright May 1994 Craig H. Reiser.