12 PROCEEDINGS OP 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 onlyj ; 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, pinuatelj 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. — PI. 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 no 

 specimens from any part of Mexico or Central America. The description 

 is drawn from Schomburgk'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 5- 

 nerved from somewhat above the base. — Bot. Gaz. xiii. 188. — Coban, 

 Dept. Alta Verapaz. Guatemala, altitude 4,300 f eet, wn 2\ierckheim (no. 

 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, o-nerved from the base, 

 3 to 4 inches long, 2 inches broad. — Schz. Bip. in Hemsl. 1. c. (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. 

 ■I- 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 o^f Buenos Ayres, Costa Rica, Plttier, no. 4433. 



9. M. Guaco, Humb. & Bonpl. Leaves {ex icone) denticulate. — 

 PI. iEquin. ii. 84, t. 105, Said by Index Kew, to equal M. amara^ 



