JONES. — A REVISION OF THE GENUS ZEXMENIA. 163 



as long as the body ; squaruellae numerous, short, distinct or somewhat 

 connate. — Abh. Naturf. Gesellsch. Halle, xv. 328 (1881). — South 

 America. Specimens examined, — Peru : Matthews, no. 1383 (fragments 

 of the type, in herb. Gray). 



b. Achenes rather short and broadly winged, or strongly constricted at the summit. 

 Mexican species. 



1. Involucral scales subequal. 



37. Z. scandens, Hemsl. Shrub, climbing or reclining ; branches 

 rusty-pubescent : leaves thick or leathery but varying to thinner and 

 submembranaceous, from ovate to oblong-lanceolate, subcordate to some- 

 what attenuate at the base, acuminate to obtuse at the apex, serrate or 

 subentire, above scabrous or strigose, beneath villous-hirsute, 7 to 13 cm. 

 long : peduncles 1 to 4 cm. long, corymbosely arranged, slender ; heads 

 rarely over 1 cm. high ; involucre 3-4-seriate, about 1 cm. broad, sub- 

 cylindrical or campanulate ; bracts from appressed and closely imbricated 

 to rather loosely spreading : disk-flowers exceeding the involucre : achenes 

 of the ray-flowers from strongly 3-winged to narrowly 2-winged (the 

 third angle wingless) ; wings generally prolonged beyond the neck but 

 not confluent with the awns ; awns about as long as the body, enlarged 

 below, subequal, pubescent ; squamellae distinct or somewhat connate ; 

 achenes of the disk-flowers 2-winged, 2-awned. — Biol. Cent.-Am. Bot. 

 ii. 174 (1881). Z. trachylepis, Hemsl. 1. c. 175 (1881). Z. dulcis, 

 Coulter, Bot. Gaz. xvi. 99 (1891). — Southern Mexico and Central 

 America. Specimens examined, — Vera Cruz : Valley of Cordova, 

 Bourgeau, no. 1930 (type); Cordova, Gray, coll. of 1885; Fortin, near 

 Orizaba, Kerber, no. 285 ; Coatzacoalcos, G. L. Smith, no. 976. Chiapas : 

 Tuxtla, C. Sf E. Seler, no. 1897. Yucatan and Tabasco: Johnson, 

 no. 24. Guatemala: Rio Dulce, J. D. Smith, no. 1607; eastern por- 

 tion of Vera Paz and Chiquimula, Watson, no. 16. This species is 

 highly variable and perhaps composite, but constant characters for its 

 division have not been found. 



2. Outer involucral scales longest, spreading and foliaceous. 



38. Z. virgulta, Klatt. Shrub with fuscous-hirsute branches : leaves 

 ovate-lanceolate, 5 to 15 cm. long, acuminate at the apex, acute to 

 rounded at the base, subentire to serrate, somewhat reticulate-veiny, 

 above strigose, beneath villous ; petioles 1 to 2 cm. long : peduncles 1 to 

 5 cm. long, cormybosely arranged, slender, pubescent; heads about 1 cm. 

 high ; involucre campanulate, 1 to 2 cm. wide (including the spreading 

 bracts) ; outer bracts long, linear-lanceolate, foliaceous, spreading or re- 



