Heterotheca sessiliflora var. echioides (Benth.) Semple is the most widely distributed of the races within the species and generally occurs at lower elevations except in the the Tehachapi Mts. It has numerous hispid-strigose hairs on its stems and leaves giving shoots a whitish halo. It is the "glue" holding the complex together as single species. It hybridizes with var. camphorata and var. fastigiata, var. sanjacintensis, and possibly var. sessiliflora. The variety is diploid (2n= 18).
Nesom (1997) treated it as Het. echioides (Benth.) Shinners var. echioides.
Last revised 2 May 2025 by J.C. Semple
© 2025 J.C. Semple, including all photographs unless otherwise indicated
1-2. Heterotheca sessiliflora var. echioides. 1. Habitat and small plants, Semple & Chmielewski 8962, San Luis Obispo Co., California. 2. Large multi-stemmed plant, Semple et al. 5635, Ventura Co., California. 3. Habitat and tall plants, Semple & Chmielewski 8943, Monterey Co., California. 4. Upper stem, leaves and heads, Semple et al. 5634, Ventura Co., California.