eH 
E 
ANALYTIC KEV* TO THE BIOTIAN ASTERS 
GENUS ASTER 
SECTION I, BIOTIAN ASTERS 
Broad cordate leaves present t; upper cauline if cordate are 
petioled (not clasping as in A. undulatus and other Diversifolial 
Asters); dilated petiole-bases occasional only, and then not con- 
spicuously clasping (unlike A. undulatus); coriaceous bracts pres- 
enti; radical leaves more strongly developed than in other 
Asters; phases of life-history more strongly accentuated than in 
other Asters ; variability at its height. 
Includes the non-fruticose portion of the genus Eurybia of 
Cassini, 1818, and of Nees, 1832, which portion became the Brora 
of De Candolle, 1836. 
SussEcrioNs DIVARICATI AND CURVESCENTES. White rays; noglands; in- 
volucre not large, usually 1 in. high or less; rays usually under 12, chiefly 
“bidentate ; thin soft smooth leaves prevalent; rootstocks chiefly rather slender ; 
ow 
DJVARICATI. Radicals few and Ba ae seldom produced ; involucre 
soon cylindrical ; ramification somew te (subpinnate in 30, 31, A 
flower-buds ovoid ; chief bracts apt to remain iir to or toward the a 
Y^. 1-79. 
CURV ESCENTES. Radicals usual, numerous and large; involucre narrowly 
abri flower-buds priva ; chief bracts apt to be narrow ; leaves often 
arge and thickish. 40-5 
SuBsECTION MACROPHYLLI. Violet rays, and glands, present. Sf. 55-84. 
DIVARICATI 
DIVISION A DIVARICATE ASTERS proper. Thin n pc 
ranous leaves, in polymorphous series on the s Disks turning 
dan ird brown or full-brown. Teeth sharp, sig "hoc aie 
te or chanfer-obtuse. Stem chiefly green. 
* Compare, also, the single-line key placed for reference-use at end of volume. 
f There are species in which cordation, however, is rare and slight, as in 4. 
aucuparius, A. Herveyi, and A. commixtus ; it is perhaps still more so in A. mirabilis. 
shoot. 
t Like the other broad-leaved asters ; which have usually narrower bracts, however, 
89 
