1470 coNTinBUTioxs fkom the jStational herbarium 



3. Ophryosporus petraeus Robinson, Contr. Gray Herb. n. ser. 75: 4. 1925. 



Eupatorium piAraeum Robinson, Proc. Amer. Acad. 41: 275. 1905. 



Michoacan and perhaps Guerrero. 



Shrub 1.5 meters high; stem terete, single, erect, purple-spotted; leaves alter- 

 nate, broadly ovate, acutish to acuminate, angled as well as irregularly crenate- 

 dentate, almost palmately nerved from near the base, 9 to 11 cm. long, 8 to 9 cm. 

 wide; panicle pyramidal; heads about 10-flowered; phyllaries (except the outer- 

 most) elliptic, very obtuse or rounded at apex, well imbricate in about 3 series. 



18. MIKANIA Willd. Sp. PI. 3: 1742. 1804. 

 Reference: Robinson & Greenman, Synopsis of the Mexican and Central 

 American species of the genus Mikania, Proc. Amer. Acad. 32: 10-13. 1896. 



Shrubby or herbaceous, scandent; leaves opposite, usually ovate, petioled; 

 heads panicled, 4-fiowered; involucre of 4 equal phyllaries; achene 5-angled; 

 pappus multisetose, uniseriate. 



The names "guaco," "huaco," and "chichicaste" are reported as used in 

 Mexico for plants of this genus whose specific identity is uncertain. 

 Heads racemosely or spicately arranged on the branches of ample pyramidal 

 panicles. 



Heads pedicellate; pappus sordid 1. M. houstoniana. 



Heads sessile; pappus bright white 2. M. pterocaula. 



Heads in pyramidal, roundish, or flattish cymose panicles. 



Stem and branches densely hirsute or setose-pilose with tawny hairs. 



3. M. eriophora. 

 Stem and branches not setose-pilose. 



Involucre more or less densely puberulous; heads 8 to 10 mm. high. 

 Leaves ovate, entire, strongly 5 or 7-nerved, subcoriaceous. 



4. M. tonduzii. 

 Leaves usually hastate-lobed or toothed, mostly 3-nerved, thin. 



Heads pedicellate; phyllaries obtuse 5. M. punctata. 



Heads usually sessile; phyllaries acute or acutish 6. M. cordifolia. 



Involucre nearly or quite glabrous; heads about 7 mm. high. 



7. M. g^onzalezii. 



1. Mikania houstoniana (L.) Robinson, Proc. Amer. Acad. 42: 47. 1906. 

 Eupatorium houstonianum L. Sp. PI. 836. 1753. 



Eupatorium houstonis L. Syst. Nat. ed. 10. 2: 1204. 1759. 



Eupatorium fruticosum Mill. Gard. Diet. ed. 8. Eupatorium no. 6. 1768. 



Mikania houstonis Willd. Sp. PI. 3: 1742. 1804. 



Willoughbya houstonis Kuntze, Rev. Gen. PI. 1: 372. 1891. 



Veracruz to Panama and southward; type from Veracruz. 



Shrubby twiner, essentially glabrous, or the inflorescence puberulous; leaf blades 

 ovate, 5 to 13 cm. long, acuminate, rounded at base, entire, firm; heads very 

 numerous, about 5 mm. high; involucre 3 mm. long. "Palo guaco" (Urbina). 



2. Mikania pterocaula Schultz Bip. (Hemsl. Biol. Centr. Amer. Bot. 2: 103. 



1881, nomen nudum); Klatt, Leopoldina 20: 91. 1884. 

 Known only from the type locality, Mirador, Veracruz. 



Glabrous twiner; branchlets 6-winged; leaves ovate, acuminate, dentate, thin; 

 heads very small. 



3. Mikania eriophora Schultz Bip. (Hemsl. Biol. Centr. Amer. Bot. 2: 103, 



1881, nomen nudum); Robins. & Greenm. Proc. Amer. Acad. 32: 12. 1896. 



Willoughbya eriophora Kuntze, Rev. Gen. PI. 1: 372. 1891, nomen nudum. 



Known only from the type locality, Mirador, Veracruz. 



Shrubby (?) twiner, densely tawny-hirsute-tomentose, the inflorescence woolly; 

 leaf blades ovate, 7.5 to 10 cm. long, 5 cm. wide, acuminate, cordate, tomentose 

 beneath; heads in large pyramidal panicles. 



