154 PROCEEDINGS OF THE AMERICAN ACADEMY. 
the disk ; disk-corollas considerably longer than the involucre: awns 
of the disk-achenes 2, longer than the body of the achene, much exceed- 
ing the involucre ; ray-achenes slightly margined, with 2 tooth-like awns 
and one siender and bristle-like. — Contrib. U. S. Nat. Herb. i. 103 
(1891). — Western Mexico. Specimens examined, —Sonora: Alamos, 
Palmer, no. 645, coll. of 1890 (co-type, in herb. Gray). 
+ + Heads numerous; peduncles fasciculate, terminal and subterminal. 
++ Involucral bracts 2 mm. or more broad, imbricated in several series, commonly 
appressed ; heads small; involucre generally less than 5 mm. broad. ; 
= Achenes 4 to 5 mm. long, those of the ray-flowers 3-awned, the awns on the 
outer angles short, tooth-like, on the inner long and bristle-formed; achenes 
of the disk-flowers with 2 awns as long as the body. 
1. Some of the outer bracts of the involucre reflexed: petioles generally over 
1 cm. long. 
19. Z. gracilis, n. sp. Shrub with long very slender branches : leaves 
ovate to lanceolate, 5 to 10 em. long, 2 to 4 cm. wide, acuminate to 
rounded at the base, very acute or acuminate at the apex, serrate except 
hear the ends, strigose above, the hairs with swollen bases, the lower 
surface sparsely short-strigose ; petioles 5 to 15 mm. long: peduncles 4 
to 8 cm. long, slender, commonly in 3 or 4 of the upper axils, superposed 3 
heads 1 to 1.5 cm. high; involucre 4 to 7 mm. broad, cylindrical, 2-3- 
seriate ; outer bracts considerably the shortest, generally reflexed, ciliate: 
ligules orange-yellow: achenes as in the preceding species. — Western 
Mexico. Specimens examined,— Co.ima: Colima, Palmer, no. 163, 
coll. of 1897 (type, in herb. U. S. Nat. Mus.). 
2. Outer bracts of the involucre not recurved or reflexed: petioles less than 1 cm. 
1 
ong. 
“age Z. CEANOTHIFOLIA, Sch. Bip. Shrub 2 to 3 m. high; branches 
striate, roughened by lenticels; branchlets pubescent: leaves from . 
broadly ovate to narrowly oblong-lanceolate, usually ovate-lanceolate, 
acute or acuminate at the apex, acute to rounded at the base, serrulate, 
reticulate-veiny, sparsely scabrous-pubescent to densely strigose above, 
strigose to coarsely and densely pubescent beneath; petioles 5 to 10 mm. 
Jong: peduncles 1 to 3 cm. long, in terminal or subterminal fascicles; 
heads 5 to (occasionally) 10 mm. high; involucre 3—5-seriate, 4 to 5 mm. 
broad; outer bracts ovate, very obtuse to abruptly acuminate, much 
shorter than the inner: ligules 5 to 7, oblong, emarginate, orange-yellow ; 
disk-flowers numerous: ray-achenes 4 mm. long, about 1 mm. wide, 
linear-ovate, with narrow margins, their pappus of 2 short teeth and one 
