46 
Fertile prairies, or sterile places, on the Upper Missouri and Yel¬ 
lowstone/ to the mountains and south to Santa Fe.— Size and shape 
of the joints variable ; fruit-bearing joints compressed, 1| - 2 inches 
long, 1 - Ij-wide, and thick; others smaller and more tumid. 
Leaves a line long, hardly longer than the large pulvilli, red. Pul- 
villi 4-6 lines apart, bristles very few, short, whitish, on the old joints 
a little more numerous, coarser, dirty yellow. Lower radiating spines 
2-4 lines long; central spines 6-10 lines long, the other interior 
spines 3-8 lines long, often similar to the smaller lower spines. 
Fruit rather fleshy through the winter, getting dry in spring, nearly 
an incli long, with 20-25 pulvilli, of which only the upper ones bear 
a few short spines. Seeds few, usually only 5 or 6 in each fruit, 3 
lines in diameter, with a wide and thick obtuse corky margin. — Often 
sterile, but abundantly propagated by the fragile joints. 
28. O. brachyarthra, E. & B. 1. c. : adscendens; articulis ovatis 
orbiculatisve tumidis ssepe subglobosis tuberculatis; pulvillis confer- 
tis parce setulosis; aculeis 3-5 validioribus 1-2 fuscatis patulis vel 
syberectis, caeteris deflexis ; floris parvi ovario subgloboso pulvillos 12 
- 15 vix aculeolatos gerente ; stigmatibus 5. 
Inscription Rock near Zuni. The short and tumid joints (10 - 15 
lines long) resemble the joints of a finger; the pulvilli 2-4 lines 
apart, even in the oldest parts of the plant with very few bristles; 
longer spines 9 - 12 lines long, terete. Ovary less than half an inch 
long. Flower apparently an inch in diameter. — Perhaps too near 
O. fragilis; but in the absence of good flowers and fruit, it is im¬ 
possible to say whether it does not belong to even a different section, 
perhaps to the Glomerate Salm. 
Subgen. 3. Cylindropttntia, E. in B. C. R. Articuli cylindracei: 
flores magni vel parvi: bacca plerumque sicca : semina immarginata 
seu vix marginata: embryo circa albumen copiosius subcircularis ; 
0. ft. tr. <2^ 
cotyledones contrarise seu obliquae, subinde parallel®.. 
§ 1. Clavatce: prostratae : articuli breves, clavati, adscendentes, tex- 
tura lignosa laxe reticulata : flores flavi majusculi: bacca sicca, 
pulvillis numerosis setosissimis stipata, floris rudimentis persisten- 
tibus coronata. 
29. O. clavata, E. in Wisl. Rep.: articulis breviter clavatis laete 
viridibus; tuberculis ovatis; foliis subulatis minutis; aculeis albidis 
