14 PITTONIA. 
is an arid and subsaline half-desert country, a region of cacta- 
ceous and salicorniaceous plants, probably about as different 
from the region of Rosa pratincola as Arabia is from Eng- 
land ; a consideration which does not seem to have entered 
the minds of our American rhodologists—if we have any— 
much less those of the European students of the genus. 
Rosa Arkansana has not, I think, been collected a second 
time; and as I spent many a week in arduous collecting 
about Cañon City, in different years between 1873 and 1896, 
without having seen original R. Arkansana, 1 entertain a 
suspicion that it may have been founded on some corymbose- 
flowering precocious shoot from the root of the so-called 
V. blanda of that region, or perhaps of R. Fendleri. But, 
apart from the antecedent improbability of this our eastern 
prairie species being also an inhabitant of a cactus desert, 
the western and xerophilous rose, the real R. Arkansana, is 
glabrous, while ours is pubescent; it has stipules both gland- 
ular and prickly, while ours has them softly pubescent only ; 
it has sepals reflexed in fruit, while in ours these are erect. 
New CHORIPETALOUS EXOGENS. 
AQUILEGIA ELEGANTULA. Erect, slender, mostly less than 
a foot high, glabrous except as to the inflorescence, the pe- 
duncles and exterior of the flowers hirtellous-pubescent ; 
the long-petioled and almost exclusively radical leaves 
glaucous beneath: flowers mostly solitary, terminating the 
merely bracted scapiform stems: flowers small, about 1 
inch long, the light-green sepals and light-yellow limb of 
the petals erect; spurs straight, longer than the sepals, 
rather widely inflated above and this part of the flower 
light-searlet: filaments short; styles elongated and exserted- 
Southern Colorado, in Slide Rock Cafion,and on the flanks 
