( 203 ) 
66. Vernonia dictyophlebia sp. nov. 
rubby, erect, 1-2 m. high; stem terete or aia striate, 
eaves firm, spreading, ovate or ovate- velliptic, 6-10 cm. long, 3-6 
cm. wide, broadest below the middle, tapering to an acute or sub- 
acuminate tip, obtuse to broadly rounded or subcordate at base, 
sharply irregularly serrulate, green and scabrous above, paler 
reticulated veins; petioles pubescent, 3-10 mm. long; upper and 
rameal leaves similar, but successively reduced to 1.5 cm. in length; 
inflorescence depressed-hemispheric, 1-2 dm. wide; heads 15-20 
mm. wide, all on peduncles 2-4 cm. long with a few scarious bracts 
resembling the outer scales; involucre broadly campanulate, 12-15 
m. 
to broadly rounded or retuse at the tip, minutely cuspidate or with the 
midnerve prolonged into an awn not over § mm. long; achene 4mm. 
long, eens ribbed, densely glandular in the furrows; pappus 
white, 8 mm 
oo ee Michoacan, Pringle 3347, Hlolway 3105; 
Oaxaca, Gonzales & Conzatti 867. The type is Pringle 3347, in 
the herbarium of Columbia University. 
Sharply distinguished from V. Alamanz by the shape and pu- 
bescence of the leaves and by the shape of the involucral scales. 
(ii) Species-group Zexanae 
Heads few, 21-many-flowered, all on ascending peduncles, form- 
ing a lax very irregular inflorescence; leaves ascending, broadest 
at or above the middle, scabrous above, glabrous or nearly so beneath. 
Four species of the Sonoran region in Mexico and the Texan region 
of the United States. The three Mexican forms occupy a continu- 
ous area, none of them occurring north of the Rio Grande. The 
single Texan species is geographically distinct from the others. It 
resembles V. Arvendbergid very closely and is to be regarded as a 
comparatively recent offshoot from that species. Once seen, the 
group is always recognized by its singularly loose irregular in- 
florescence. 
67. VERNONIA TEXANA (A. Gray) Small, Fl. S.U.S. 1160. 1903 
Vernonia angustifolia texana A. Gray, Syn. Fl. 1: 91. 1884. 
Type locality: Texas 
Distribution: from central Arkansas south and southwest to the 
Gulf of Mexico. 
