Hemizonella minima

Leaf blades 5-25 × (0.5-)1-3 mm. Involucres (1-)2-4 × (1-)2-4 mm. Disc corollas 1-2.5 mm. Ray cypselae 1.8-2.8 mm; disc cypselae 1.8-2.8 mm. 2n = 42-44.

Flowering Apr-Aug. Gravelly or rocky, usually open sites, scrublands, meadows, forests; 300-2900 m; B.C.; Calif., Idaho, Mont., Nev., Oreg., Wash.

Hemizonella minima is self-compatible, like most other tarweeds that are distributed widely in western North America. Taylor 8147 (JEPS), from the Sierra Nevada (Tioga Peak, Mono County, California), is an unusually late-flowering (15 Sep 1982) and high-elevation (2900 m) collection.