152 PROCEEDINGS OF THE AMERICAN ACADEMY, 
volucre: achenes 6 to 7 mm. long, narrowly margined on the inner edge; 
squamellae minute or none. — Mexico. Specimens examined, — GUER- 
RERO: mountains near Iguala, alt. 1230 m., Pringle, no. 8411 (type, in 
herb. Gray).” 
2. Scales of the involucre not recurved at the apex. 
‘14. Z. Guressrecurn, Gray. Shrubby or arborescent: leaves 
ovate-lanceolate, acuminate, reticulate, submembranaceous, hirtellous- 
scabrous, subcordate: peduncles terminal, solitary or in cymes of 3, 
frequently thickened upward, several times longer than the upper leaves; 
heads about 15 mm. high; involucre hemispherical, 1 to 2 cm. in diam- 
eter, 3-seriate; outer bracts orbicular-ovate, appressed, considerably 
shorter than the others; the inner long, narrower, membranaceous at the 
tip: ligules orange-yellow, only slightly exceeding the disk; disk-flowers 
numerous, generally exceeding the involucre: achenes somewhat mar- 
gined, about 5 mm. long, 1 to 2 mm. wide; awns, in the disk-achenes, 
more than half as long as the body, in the ray-achenes shorter ; squamellae 
minute.— Pl. Wright. i. 113 (1852), as Ghiesbrechtii ; Hemsl. Biol. 
Cent.-Am. Bot. ii. 172. -— Mexico. Specimens examined, — Without 
precise locality, Ghiesbreght, no. 885 (type, in herb. Gray). Comma: 
Palmer, no. 1241, coll. of 1891. Guerrero: Acapulco, Palmer, 00. 
491, coll. of 1895; between Juchitango and Omelepec, Nelson, no. 2312. 
Tepic: Palmer, Jan. 5 to Feb. 6, 1892. Some of these specimens have 
been distributed as Z. Greggii, a species which should be readily distin- 
guished by its prominent squamellae, very narrowly fusiform achenes, 
and sessile leaves. 
15. Z. macrocepHara, Hemsl. Suffruticose or fruticose, densely 
pubescent above; leaves firm, subsessile, lanceolate to elliptical, attenU- 
ate, serrate, short-pilose and more or less scabrous with tuberculate hairs 
above, strongly reticulate-veiny and densely hirsute beneath ; peduncles 
longer than the upper leaves, terminal, usually in cymes of 3; heads 1 
to 2 cm. high; involucre 10 to 15 mm. broad; bracts somewhat decus- 
sately arranged, ovate, from acute to rounded at the apex, outer pair 
quite small: achenes rather long and slender (as in Z. Greggit), those 
of the disk with slender awns less than half as long as the body, those of 
the ray with tooth-like awns; squamellae none. — Biol. Cent.-Am. Bot. 
ii. 173 (1881). Lipochaeta macrocephala, Hook. & Arn. Bot. Beech. 
oy. 436.— Southern Mexico. Specimens examined, — GUERRERO: 
_ Acapuleo, Hinds, no. 1841 (a portion of the type material sent from 
herb. Kew). 
x 
