GLEASON: TAXONOMIC STUDIES IN VERNONIA 249 
striate and reddish brown under the pubescence; leaf-blades ovate- 
oblong, as much as 38 X 80 mm., narrowed toward the sessile 
base or into a short margined petiole, undulate and irregular at 
the entire margin or rarely with a few low salient teeth, frequently 
a little revolute, acute at the apex or short-acuminate into a small 
subulate tip, dark-green and rugose above with impressed veins 
and scabrous with papillose hairs or hair-bases, gray or nearly 
white beneath with a close fine tomentum; lateral veins promi- 
nent, ascending and straight almost to the leaf-margin; upper and 
bracteal leaves similar but smaller; heads five-flowered, in a sympo- 
dial raceme, standing opposite and a little (2-3 mm.) below a 
bracteal leaf which later bears secondary heads in its axil, primary 
heads eight to ten; involucre 8 mm. high, 2.5 mm. wide, with its 
stiff scales imbricate and appressed at the base and squarrose at 
the tip, lanceolate-oblong to ovate-oblong, broadest below or near 
the middle and long-acuminate into a subulate, glabrous, terete, 
callous tip, the outermost green, one-half the length of the purple 
inner ones, and all papillose-villous with erect hairs on the exposed 
portion; corolla apparently pale purple, its tube glabrous, not 
ampliate above, 5 mm. long, its lobes glabrous, 3 mm. long by 
0.6 mm. wide, with parallel sides and triangular tip; filaments 
glabrous, attached at two thirds the height of the tube; anthers 
2.8 mm. long, minutely rounded at the triangular tip, their obtuse 
bases 0.5 mm. long; style hairy along the upper 1.4 mm., its 
branches I.4 mm. long, tapering, hairy on the outer side; achene 
2.5 mm. long, shallowly ten-ribbed, pubescent with short erect 
hairs on the ridges; pappus-bristles pale tawny, 6.5 mm. long, 
barbellate; paleae linear-lanceolate, 1.0-I1.1 mm. long by 0.09- 
0.18 mm. wide, trough-shaped and pubescent on the inner face. 
Tyre: Purpus 7060, collected in the Sierra de Tonala of Chi- 
apas, Mexico, October, 1913, and deposited in the herbarium of the 
University of California as number 173434. Other sheets of the 
same collection are in other American herbaria and agree in every 
particular with the type. 
Vernonia jucunda is the first species of the section Stenocepha- 
lum to be discovered in North America. Other members of the 
section are South American; one species, probably undescribed, 
occurs in Colombia and a number in Brazil. The section is 
characterized by few-flowered heads set a short distance below the 
bracteal leaf, by an involucre constricted at the throat and com- 
Posed of subulate, more or less squarrose scales, and by leaves 
Which are usually revolute and tomentose beneath. 
