24 VARIATION IN ASTER 
last year’s stock, and in most of the narrow-leaved species, in 
which they are apt to be of this latter description. 
Slenderness or stoutness of rootstock seems quite constant within 
the species, rather more so than the length. As a general thing 
there is an increase in stoutness of rootstock through the suc- 
cession of Biotian species in the order considered in this paper, 
beginning with the slender Divaricati and proceeding to the stout 
Macrophylti. 
Succulescence of rootstock, a character which requires field ob- 
servation, accompanies rapid growth and turgid stout rhizomatous 
condition ; it seems to be always found in any species entering the 
plantain-leaf stage (so in A. divaricatus fontinalis, A. viridis, A. 
roscidus, A. decaphyllus). 
Irrespective of that stage it seems to be regularly character- 
istic of plants of A. violaris and A. quiescens, in which case succu- 
lescence extends also to the stem and the leaves. It seems to be 
frequent if not regular in A. multiformis in the same way ; not 
frequent in A. zanthinus; regular in A. nobilis ; doubtfully pres- 
ent in the other Macrophylt. 
Position of rootstock. — Upright or suberect position char- 
acterizes the short thick turionic rootstock of the plantain-leaf 
stage of any species.  Biotian rootstocks otherwise are horizontal 
or nearly so, upcurving at the ascending end ; except where grow- 
ing in crevices of rocks or among stones, when they may assume 
any position, and are frequently erect (as sometimes in 4. carme- 
sinus, A. Clayton, A. mollescens). 
Position of rootstock is liable to so many chance modifica- 
tions from immediate environment that it is only after extensive 
comparisons that it can be used at all as a character. 
COLOR-CHARACTERS 
Color of rays. — This is sufficiently constant to be of decided 
value as a character. White rays are as a rule dissociated from 
glands; traces of purple accompany glands in Biotian species, 
as in the more familiarly-known glandular species, Gray's G/az- 
dulosi, etc. 
In the Divaricati and Curvescentes, if a color is present in rays, 
it is rose or rose-purple or crimson, or a copper-red; and not a - 
