148 PROCEEDINGS OF THE AMERICAN ACADEMY. 
(1842).— Southern Mexico. Specimens examined, —Moretos: near 
Cuernavaca, 1520 m. alt., Pringle, no. 6225; Ghiesbreght, no. 379 (type, 
in herb, Gray). 
+++ Awns of the disk-achenes usually about half as long as the body. 
46.2. Greeeu, Gray. Shrub or lignescent herb, 2 to 8 m. high: 
leaves large on the lower part of the stem, 1.5 dm. long, 8 cm. wide, 
smaller above, sessile or nearly so, ovate to lanceolate, serrate, obtuse to 
acuminate, cordate or subcordate, reticulate-veiny, scabrous: peduncles 
2 to 25 em. long, stout, naked or bearing 1 or 2 scale-like bractlets ; heads 
about 15 mm. high; involucre 1.5 to 2.5 cm. broad, its bracts 3-seriate, 
ovate or lanceolate, the outer attenuate, appressed, several-nerved, the 
inner rounded and chartaceous at the summit: ligules rather small, com- 
monly not exceeding the disk ; disk-corollas with long slender tubes, gener- 
ally surpassing the involucre: achenes 5 to 6 mm. long, narrowly fusiform, 
the angles only slightly margined; squamellae about 1 mm. in length. 
— Pl. Wright. i. 113 (1852); Hemsl. Biol. Cent.-Am. Bot. ii. 172.— 
Southern Mexico. Specimens examined, — Jatisco: near Guadalajara, 
Pringle, no. 1769; Tequila, Palmer, no. 356, coll. of 1886; between the 
city of Mexico and Mazatlan, Gregg, no. 1003 (type, in herb. Gray). 
* %* Squamellae minute (less than 0.5 mm. long or entirely wanting). 
+ Heads few, in terminal 3-headed cymes or solitary (in Z. fruticosa, the pe- 
duncles commonly in several of the’ upper axils). ; 
++ Herbs, 3 to 9 dm. high, from tuberiform roots or thickened lignescent base. 
= Peduncles very long, usually not less than 1 dm. in length. 
7. Z. PopOCcEPHALA, Gray. Herbaceous, 6 to 9 dm. high, somewhat 
branched from a lignescent base; roots much thickened, fusiform ; stems 
spreading-hirsute, bearing about 5 pairs of leaves and 1 to 8 long-pedun- 
cled heads: leaves subsessile, ovate-oblong to oblong-lanceolate, acute at 
the apex, subcordate, rounded or abruptly narrowed to a subcuneate base, 
serrate, 6 to 8 cm. long, 15 to 32 mm. wide, coarsely pubescent on both 
sides: heads about 1 em. high; involucre cylindrical or campanulate, about 
1 cm. broad, 2-seriate; outer bracts oblong-ovate, subacute, hirsute: Taye 
flowers about 12; ligules 13 mm. long; disk-corollas scarcely exceeding 
the involucre: achenes 3 mm. long, widest at or near the summit; awns 
shorter than the body, widened at the base, those of the ray-achenes 
usually reduced to strong teeth; minute squamellae sometimes present. 
— Syn. Fi. i. pt. 2, 286 (1884); Rose, Contrib. U. S. Nat. Herb. } 
103; Britton & Kearney, Trans. N. Y. Acad. Sci. xiv. 44. Ver’ besind 
