JONES: — A REVISION OF THE GENUS ZEXMENIA. 163 
as long as the body; squamellae numerous, short, distinct or somewhat 
connate. — Abh. Naturf. Gesellsch. Halle, xv. 328 (1881). — South 
America. Specimens examined,— Perv: 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. scanpENs, 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 spex, serrate or 
subentire, above scabrous or strigose, beneath villous-hirsute, 7 to 13 em. 
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. Ceut.-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; Coatzacoaleos, C. L. Smith, no. 976. CHIAPAS: 
Tuxtla, C. § EH. Seler, no. 1897. YucaTan and Tasasco: Johnson, 
no. 24. GuaTemMALA: 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 
ivision have not been found. 
2. Outer involucral scales longest, spreading and foliaceous. 
38. Z. vircuvta, Klatt. Shrub with fuscous-hirsute branches: leaves 
ovate-lanceolate, 5 to 15 cm. long, acuminate at the apex, acute to 
roun at the base, subentire to serrate, somewhat reticulate-veiny, 
above strigose, beneath villous; petioles 1 to 2 cm. long: peduncles 1 to 
5 em, long, cormybosely arranged, slender, pubescent ; heads about 1 cm. 
high ; involucre eampanulate, 1 to 2 cm. wide (including the spreading 
bracts); outer bracts long, linear-lanceolate, foliaceous, spreading or re- 
