Pericome macrocephala Robinson

Pericome macrocephala B. L. Robinson, Proc. Am. Acad 43:42. 1907.
A tall perennial, growing in bunches; stems subterete, striate, somewhat brownish, grayishpuberulent; petioles slender, 2-3 cm. long; leaf-blades triangular-hastate, 5-6 cm. long, 4-5 cm. wide, caudate-attenuate, grayish-puberulent, pedately 3-5-ribbed; heads numerous, cymose; pedicels pubescent, 1-2 cm. long; involucre ellipsoid, 10-12 mm. high, 5-7 mm. broad; bracts puberulent, imited to near the top, grayish-pubescent, acute; corollas Hght-yellow, 1 cm. long; tube 3 mm. long, glandular-puberulent; throat cylindric; teeth 4, short, ovateoblong, obtuse; achenes black, narrowly oblong, sparingly hirsute or glabrate on the faces, densely hirsute on the margins; pappus of squamellae scarcely longer than the hairs; awns wanting.
Type locality: San Ram6n, Durango. Distribution: Known only from the type locality.