Phaulothamnus spinescens A.Gray in Proc. Amer. Acad. Arts 20: 294. 1885
Phaulothamnus spinescens in Proc. Amer. Acad. Arts 20: 294. 1885
Type: "N. W. Sonora, Mexico, about thirty miles south of the U. S. boundary, and on the Rio Altar, nearer the line, C. G. Pringle, August, 1884."1
Phaulothamnus spinescens in Proc. Amer. Acad. Arts 20: 294. 1885