N 
VoL. 5] New Species of Mexican Plants. 239 
ulose-dentate, thick in texture, with stout midnerve, 2 cm. long, 
I cm. wide, cuneate into a petiole 3-6 mm. long: heads 1:5 cm, 
high, terminating the branches, eradiate: involucral scales in 3-4 
tows, thick, linear-oblong, 6 mm. long, 2 mm, wide, obtuse, 
puberulent, the lower ones bract-like upon the peduncle: outer 
paleze of the receptacle resembling the involucre, indistinctly 
Striate; inner paleze scarious and bifid at apex: corolla tube short: 
marginal akenes triquetrous; disk akenes flattened, all white-. 
villous with long hairs: pappus two persistent stout scales widened 
to the base, with or without a small intermediate awn, 
. Collected near Parras, Coahuila. No. 11 50. 
Bidens alpina. Annual, the few spreading stems sparingly 
hirsute-pubescent, 2-6 cm. long: leaves pinnate, the blade 1 cm. 
long or less and of greater width; pinnze 1-2 pairs, incised or 
 €ntire, glabrous: petioles 5-15 mm. long: heads on pubescent 
Peduncles 2-3 cm. long, 5 mm. high and 8 mm. wide including 
the short quadrate, yellow ray: involucre double, the onter of 
five linear, slightly spatulate bracts, ciliate; bracts of the inner 
involucre ovate-lanceolate: akenes 7 mm. long, nearly smooth; 
awns none or two varying from 1 mm. long to rudiments, corne- 
fous and not barbellate. 
This is a small species with short stems nearly prostrate and 
_ father inconspicuous flowers. Collected on Popocatepetl, grow- 
ing in gravelly soil above timber-line. No. 1684. 
Achenipodium. Nov. Gen. Capitula discoidea. Involuc- 
Tum campanulatum, bracteis 2-3-seriatis angustis herbaceis, 
€xterioribus brevioribus. Receptaculum convexum bracteis com- 
Plicatis flores amplectentibus onustum. Corollz tubulosze, limbo 
cylindraceo apice 5-fid. Anthere basi auriculis minutis sagittate. 
Styli rami obtusi breviter appendiculati. Achzenia a latere com- 
es Pressa, margine ciliata, basi in stipitem contracta. Pappi ariste 
| 2 setiformes, squamellis intermediis o. Frutex? Folia oppo- 
Sita, petiolata, serrata. Capitula in paniculam carymbosam dis- 
| ‘Posita. Corolle flave. 
a Achezenia stipitata iis Podachenii simillima. 
Achznipodium discoideum. Stems erect, striate, hirsute pu- 
cent: leaves lanceolate, long-acuminate, 10-14 cm. long, 2-3 
