One isolated population has been reported from the hills east of Cayucos in San Luis Obispo County.

[1] Deinandra conjugens is an annual herb growing up to about 0.5 metres (1.6 ft) in height with a solid, bristly, gland-dotted stem.

The center of the head is filled with yellow disc florets tipped with black, dark purple or red anthers.

[4] Deinandra conjugens grows in clay soils in several types of habitat, including grassland and maritime and inland coastal sage scrub.

[4] It tolerates some disturbance in its habitat, and low levels of grazing and road maintenance activities such as mowing are probably beneficial.

[4] The region in which the plant lives is heavily impacted by development and other processes and exists now in a fragmented state.

The San Diego National Wildlife Refuge created the Otay Tarplant Preserve, and Caltrans reserved a section of land for the plant near a busy highway.