12 PROCEEDINGS OF THE AMERICAN ACADEMY. 
* * Heads sessile. 
+ Heads very small: pappus bright white: branchlets winged. 
3. M. pterocaula, Schz. Bip. Glabrous twiner: leaves ovate, 
acuminate, dentate, thin, 5-nerved from the base: branchlets 6-winged. — 
Schz. Bip. in Hemsl. Biol. Cent.-Am. Bot. ii. 103 (name only) ; first 
described by Klatt, Leopoldina, xx. 4.— Mirador, Liebmann, no. 101. 
+ + Heads larger: pappus tawny or rufescent: branchlets terete, striate but 
not winged: leaves entire. 
4. M. leiostachya, Benth. Leaves large, firm in texture, ovate 
with acuminate apex and rounded base, pinnately 5-nerved from above 
the base, glabrous above, finely fuscous-pubescent on the veins beneath, 
at length wholly glabrate, the larger ones 3 or 4 inches in breadth: 
spikes 1 to 2 inches long. — Pl. Hartw. 201. — Columbia and Panama, 
Seemann, no. 446; also at Gatun Station, on the Panama Railway, 
Hayes. Said also to extend southward to Peru. 
5. M. Hookeriana, DC. Leaves narrower, thinner, 3-nerved: 
spikes less than an inch in length: pappus rufous. — Prodr. v. 195.— 
Ascribed to Nicaragua and Panama by Hemsley. We have seen n0 
specimens from any part of Mexico or Central America. The description 
is drawn from Schomburghk's no. 479 from Brit. Guiana. 
§ 2. Heads not distinctly spicate nor racemose, disposed in ample 
terminal panicles: branchlets densely tawny-hirsute or woolly. 
6. M. pyramidata, Donnell Smith. A tall climber densely cov 
ered with ferrugineous hirsute pubescence: panicle loose: heads not 
glomerate: leaves ovate, acuminate, rounded at the base, pinnately 9 
nerved from somewhat above the base. — Bot. Gaz. xiii. 188. — Coban, 
Dept. Alta Verapaz, Guatemala, altitude 4,300 feet, von Tuerckheim (n0- 
1106 of Donnell Smith’s sets). 
7. M. eriophora, Schz. Bip. Densely tawny-tomentose, the inflores- 
cence woolly: heads somewhat glomerate: leaves ovate, cordate, sharply 
acuminate, pubescent above, tomentose beneath, 5-nerved from the base, 
3 to 4 inches long, 2 inches broad. — Schz. Bip. in Hemsl. |. ¢. (name 
only). — Mirador, Liebmann, no. 94. 
§ 3. Heads disposed in roundish or flattish cymose corymbs. 
* Heads rather large, when mature 4 to 5 lines in length. 
+ Scales of the involucre obtuse: leaves ovate, distinctly cuneate at the base- 
8. M. olivacea, Klatt. “Leaves entire.” — Bull. Soc. Bot. Belg- 
xxxi. 195. — Forests of Buenos Ayres, Costa Rica, Pittier, no. 4433. 
9. M. Guaco, Humb. & Bonpl. Leaves (ex icone) denticulate-— 
Pl. Aquin. ii. 84, t. 105. Said by Index Kew. to equal J ? 
