Presumably Opuntia form "R" (just based on proximity and eyeballing -- need to get pictures of characters)
Plants are growing on mountain side that was heavily burned in the Snow Creek fire that started September 17, 2020 and consumed 6,254 acres.
Sweetbush (Bebbia juncea) A.k.a. Rush Bebbia, Chuckawalla's Delight (the flowers are delicacies to this desert lizard). Sweetbush is a native, common, aromatic, rounded, many-branched shrub in the Asteraceae family that grows on dry, rocky slopes, desert plains, and in sandy, gravely washes. The multitude of thin stems form a dense, almost spherical shrub about 1m (3ft) tall and wide. Narrow stems have short, stiff hairs that feel like sandpaper. The yellow flower heads are discoid (lacking rays). Bebbia juncea ssp. aspera has narrow, linear phyllaries with an acute to acuminate (tapering to a point) tip. The following 4 references only list this plant with the ssp. (subspecies) aspera.
Jepson eFlora https://ucjeps.berkeley.edu/eflora/eflora_display.php?tid=6785
Anza-Borrego Desert Wildflowers https://borregowildflowers.org/?type=search&searchtype=S&family=&name=Bebbia%20juncea%20aspera
Baja California Plant Field Guide, Jon P. Rebman, Norman C. Roberts, 3rd. ed, 2012, pp. 133-134.
California Desert Flowers: An introduction to families, genera, and species, Sia Morhardt and Emil Morhardt, 2004, p. 47.
Shrubs and Trees of the Southern California Deserts. Jim W. Dole and Betty B. Rose, Foot-loose Press, 1996, p 99.
California Desert Wildflowers, Philip A. Munz, 1975, p. 104.
Temalpakh: Cahuilla Indian Knowledge and Usage of Plants, Lowell John Bean and K. Saubel, Malki Museum Press, 1972 (species not listed)
CalFlora's Southern California Plant Communities http://www.calflora.net/botanicalnames/plantcommunities.html
Plants of Southern California: Regional Floras http://tchester.org/plants/floras/#abdsp (comprehensive website)
Native and Introduced Plants of Southern California by Tom Chester http://tchester.org/plants/index.html