Blepharizonia

Blepharizonia laxa occurs widely in the Inner South Coast Ranges (rarely in the Outer South Coast Ranges) north to the eastern San Francisco Bay area and northwestern San Joaquin Valley. Most recent workers have treated the taxon as a subspecies or variety of B. plumosa; following B. G. Baldwin et al. (2001), we recognize B. laxa at species rank based on molecular and biosystematic evidence for extensive evolutionary divergence. Where B. laxa and B. plumosa co-occur, the two species remain distinct and appear to be ecologically divergent, in addition to being only minimally interfertile (Baldwin et al.).

Herbage yellowish green, usually densely stipitate-glandular distally and with scattered to abundant tack-glands. Heads usually borne singly or in ± racemiform-paniculiform arrays (branches ± virgate). Involucres ± glabrate or hirsute to hispid, usually with scattered to abundant tack-glands as well. Disc pappi 0 or 0.1–1 mm. 2n = 28.

Hemizonia plumosa (Kellogg) A. Gray var. subplumosa A. Gray in A. Gray et al., Syn. Fl. N. Amer. 1(2): 312. 1884; Blepharizonia plumosa (Kellogg) Greene subsp. viscida D. D. Keck; B. plumosa (Kellogg) Greene var. subplumosa (A. Gray) Jepson

Blepharizonia laxa is a California species of tarweed known by the common name glandular big tarweed.