John C. Semple WAT

Eucephalus Nutt.

THE CASCADE ASTERS

Eucephalus is an western North American genus of 9 species of white and purple rayed asters with a chromosome base number of x=9. The majority of the species occur in the Cascade Mts. of the Pacific northwestern United States and southern British Columbia, Canada. The genus is defined on the basis of fruit, hair and phyllary traits; fruits have a quadruple pappus of a short outer series and three mid to longer series, the innermost the longest and strongly clavate; hairs are twisted and form a wooly indument when dense; phyllaries have a thickened (keeled) base. Eucephalus has been treated as Aster sect. Eucephalus, but Xiang and Semple (1996) determined that the genus was not closely related to Aster s.str. and the Symphyotrichum asters. Brouillet, Allen, Semple and Ito (2001) found the Eucephalus-Doellingeria clade to be basal to all other North America Astereae. Allen, Brouillet and Semple (2001) explored relationships and geographic patterns of subclades within the Eucephalus-Doellingeria clade. They found that two species (E. glaucodes and E. wasatchensis) usually included in Eucephalus belonged in the Eurybia group, as Nesom (1994) had proposed.

Eucephalus breweri (syn: Chrysopsis b.; Heterotheca b.); habit, heads rayless, California
Eucephalus elegans (syn: Aster perelegans)
Eucephalus engelmannii; habit & head, Wyoming; tips of primary outer and inner (clavate) series pappus bristles
Eucephalus glaucescens; shoot, Washington
Eucephalus gormani; habit, Oregon
Eucephalus ledophyllus; habit; head, Oregon
Eucephalus paucicapitatus
Eucephalus tomentellus (A. brickellioides)
Eucephalus vialis; shoot with discoid heads (NY herbarium sheet), Oregon