46 PITTONIA. 
3. O. Wanpr. Aplopappus Fremonti, var. Wardi, Gray, 1 
Syn. Fl. i. part 2. 128 (1884).—Plant apparently as rare as | 
either of the two foregoing; obtained only by Mr. L. F. - 
Ward somewhere in Wyoming; certainly wholly distinct — 
from the next. : 
4. O. FOLIOSA. Pyrrocoma foliosa, Gray, Journ. Bost. Soc. - 
(1843) 5. Aplopappus Fremonti, Gray, Proc. Philad. Acad. 
(1863) 65.—Plentiful on clayey plains along the upper Ar- 
kansas in Colorado, yet not known from any point besides. 
Although when enumerating in Eryruea (vol. ii. p.70) 
the species of Pyrrocoma I allowed this plant a place in that 
enumeration, I did it with the reluctance which is there 
intimated, and should not have named it in that connec- 
tion had it not been early published under that genus. 
At the time when the limits of the genus Stenotus were 
under investigation, I could not but recognize an exce 
ingly intimate relation as subsisting between typical Steno! 
and Xylorrhiza. The two types are exactly similar, and 
equally unlike anything that should be called Aster, in vege - 
tative characters, the tufted low leafy evergreen stems of 
both springing from a branching thick woody caudex. And 
the similarity as to inflorescence, floral structure, and pecu É 
liarities of the fruit is almost as complete. The pappus i$ 
clear white in Stenotus, while in Xylorrhiza it is fulvous 0! 
darker. Here also the involueral bracts are, in general, nar 
rower and more acuminate. For the rest, the color of th 
flowers constitutes the main distinction ; Stenotus being Xa 
in favor of these mere colors as furnishing data for generi 
distinctions in this tribe of plants—a prejudice which is the 
result of long deference to high authority—I should ha 
united these two groups, white-flowered and yellow-flowere 
respectively, under the name which has precedence of pub 
