Heterotheca sessiliflora var. sessiliflora is the southern most race of the species.  It occurs near the coast from the Los Angeles area south into Baja California Norte, Mexico.  Its leaves can vary from sparsely-hairy and densely glandular to densely-hairy and sparsely-glandular.  Mexican plants can be subshrubs and more than a meter tall.  This is the type species of sect. Phyllotheca.

Heterotheca sessiliflora ssp sessiliflora Fig 15 Semple 1996