Heterotheca sessiliflora (Nutt.) Shinners includes five varieties grouped into three subspecies that make up the California Goldenaster complex. The species is native to California and northern Baja California Norte, Mexico. The species is defined by having long, thin hairs on the disc corolla lobes. These can be few in number to many and obvious. Several florets need to be examined to confirm the presence of long hair in some individuals.
The variaties have been variously treated as separate species or varieties within several separate species. This treatment follows Semple (1996) modified for Semple (2006). The recent Jepson Manual emphasized subspecies and noted the occurrence of varieties within them. Semple (1996) provided detailed descriptions of the varieties.
ssp. bolanderi (A. Gray) Semple
ssp. echioides (Benth.) Semple
ssp. fastigiata (Greene) Semple