102 PROCEEDINGS: BOSTON SOCIETY NATURAL HISTORY. 
leaves 7 to 10 cm. long, 2 to 3 cm. broad, above scabrous, beneath 
hirsute upon the veins and hnely canescent-pubescent upon the 
surface: heads (excl. the rays) 2.5 to 3.5 cm. in diameter: ligules 
about 15. — Hemsl., 1. c., 161. — Oaxaca, Ghiesbreght , no. 216 
(type in herb. Kew). We follow Dr. Gray in referring to this 
species GhiesbreghV s no. 383, from which the above characteriza¬ 
tion is drawn. 
35. G. megacephala. Stems simple, striate, scarcely at all sca¬ 
brous, covered with minute appressed hairs, also-lanate in lines 
decurrent each from either side of the short winged petioles: leaves 
ovate-lanceolate with short slender caudate acumination, serrate, 
scabrous above, hirsutulous upon the veins, but green and glabrous 
upon the surface beneath, 8 to 12 cm. long, 2 to 4.5 cm. broad : 
heads terminal, solitary, about 7 cm. broad: no rays observed.— 
Collected between Tlapa and Ayusinapa, Guerrero, Mexico, alti¬ 
tude 1,380 to 1,700 m., 13 December, 1894, E. W. Nelson , no. 
2105, distributed as G.flava. 
var. simulans. Pubescence of the stem coarser, spreading : bases 
of the hairs enlarged, white, tuberculate: leaves somewhat larger, 
less pubescent, merely cuspidate at the obtusish tip: rays about 13, 
oblong, bright yellow, 3 cm. long, 7 to 10 mm. broad.—Collected 
on the Sierra de los Morones near Plateado, Zacatecas, altitude 
2,300 m. 1 September, 1897, Dr. J. N Rose, no. 2740. This vari¬ 
ety closely simulates Viguiera excelsa , Benth. and Hook.f., which, 
however, differs technically and, as it appears, with constancy in 
its pubescent achenes which bear at the summit two conspicuous 
awns and some intermediate scales. 
= = Outer involucral bracts much shorter than the large inner ones. 
36. G. platylepis, Gray. Hirsute shrub, 1 to 3 m. high: leaves 
chiefly opposite, acuminate or attenuate at each end, very sca¬ 
brous above, paler and densely soft-pubescent beneath, 1 dm. long, 
3-nerved from considerably above the base: peduncles thickened 
upwards; heads (excl. of rays) 2 to 3 cm. in diameter; ligules 
15 to 20 in number, 2 to 3 cm. long. — Proc. Amer. acad., 19, 5; 
Klatt, Bull. soc. bot. Belg., 31, 199. G. decurrens , Ivlatt, Leopol- 
dina, 23, 90. Perimeniopsis perfoliata, Sch. Bip., acc. to Klatt, 
1. c. Tithonia seaberrima , Benth. in Oerst., Vidensk. meddel., 
1852, p. 91. T. platylepis , Sch. Bip., acc. to Benth. and Hook.f., 
1. c., 368 (name only). Mirasolia seaberrima , Benth. and Hook.f. 
