72 PITTONIA. 
MACHJERANTHERA MUCRONATA. Low esspitose perennial, 
rather smaller than M. Pattersonii, far more slender, but 
heads as large: leaves mainly basal in tufts, oblanceolate, 
entire, petiolate, at apex euspidately mucronate, nearly gla- 
brous on both faces, but margins finely ciliolate, and the 
petioles eiliate: seapiform peduneles decumbent, slender, 5 
to 6 inches high, bearing 1 to 3 large campanulate invo- 
lueres, their narrow bracts in 3 or 4 series, with long sub- 
ulate-attenuate thin-herbaceous hispidulous spreading tips 
of purple color: rays many and showy : achenes glabrous. 
Rather copious specimens of this are in the U. S. Herba- 
rium, all from Mr. Jones, and collected in Arizona in 1894, 
at two stations, designated as Thompson Cafion, and the 
Buekskin Mountains. 
BIDENs VULGATUS. Coarse and stout somewhat fastigiately 
branched annual commonly 8 to 6 feet high, obscurely pu- 
bescent or almost glabrous: largest leaves 6 to 10 inches 
long, divided into 5 lanceolate incisely serrate abruptly 
acuminate divisions all petiolulate leaflets, the two lower cut 
at base into one or more secondary leaflets: fruiting heads 
few and very large, terminating the somewhat corymbose 
branches and branchlets, the more strictly terminal ones 
$ inch high and 1i inches broad; leafy outer bracts of in- 
voluere surpassing the head, their petiolar base ciliate: rays 
few and inconspieuous: achenes thickish on the margin, 
more or less pubescent, the outer yellowish-green, sparsely 
tubereulate on the back. 
One of the commonest and most annoying of autumnal 
field and wayside weeds throughout the Eastern and Middle 
U. S, and one which has heretofore passed for B. frondosus ; 
perhaps supposed to be the type of that species. But the 
real B. frondosus of Linnzus, equally common, is a more 
slender plant, more widely branching, with heads hardly 
half as large, whose best specific character may be its nar- 
rower slenderly, or even caudately, acuminate leaflets. 
