CACTACECE. 
45 
interioribus obovatis cuspidatis petaloide-marginatis, petalis sub-13 obovato-orbiculatis emargi- 
natis s. obcordatis crenulatis Sfepe raucronulatis ; stigmatibus sub-8 viridibus in capitulum 
globosum s. conicum confertis ; bacca ovata s. subglobosa, umbilico parum depresso, pulvillis 
25-35 albo tomentosis setos albidas stramineas s. rufescentes aculeolos que numerosos breves s. 
elongatos gerentibus ; seminibus magnis plerumque irregularibus late subacuteque marginatis. 
(Plates X1Y and XV, flig. 1-10 and 1-4.) 
This variable species extends from the country north of the Upper Missouri river to the regions 
south of the Canadian and of Santa Fe, latitude 48° 35'; and from longitude 99° east of Fort 
Pierre, on the Missouri, to 112° on the San Francisco mountains. It has not been found south 
of Albuquerque, along the Rio Grande, nor in the Salt Lake valley, Utah, as tar as at present 
known. Flowering in May, fr. same fall. Nuttall discovered this common western species on 
the Upper Missouri in 1811, and described it under the name of Cactus ferox ; he noticed “8-10 
greenish stigmata” and the “dry spring fruit.” The deep purple fruit, as large as a hen’s 
egg,” attributed to our species on the authority of Dr. James, by Torrey and Gray, in their 
Flora, perhaps belongs to our 0. Camanchica ; it certainly cannot belong to 0. Missouriensis. 
It forms large spreading masses, much dreaded by travellers and their animals. Joints mostly 
suborbicular, 2-4 inches long, and 2-3| wide, light green, somewhat tuberculated from hemi¬ 
spherical elevations which bear the leaves and pulvilli, 4-6 lines apart; leaves 1^-2 lines long, 
hardly more than | line in diameter at the base, nearly twice as long as the wool in their axills; 
numerous small white spines radiating downwards and laterally, sometimes a few rather longer 
ones obliquely upwards, mostly 3-6 lines long, rarely more elongaged; central spines in the Mis¬ 
souri specimens mostly 1, rarely 2; in the southern ones, often 2-4, 1-1^, or even 2 inches long, 
terete or somewhat angular, white, or mostly with a reddish base when young, entirely brown 
red, with lighter tips. On the lower pulvilli the stouter spines are mostly wanting ; in some 
Missouri specimens, I find few and weak spines on the upper, and none at all on the lower part 
of the joints ; in other plants, from the same region, all the pulvilli are nearly equally armed 
with 5 weaker (2-3 lines long) lower deflexed, and 5 inner stouter (4-6 lines long) spreading 
spines. Flowers 2-3 inches in diameter, ovary, with subulate sepals, similar to the leaves, 
spines already present, but not as long and stiff as in the fruit. Petals yellow towards the base, 
or sometimes almost entirely rose-colored, orange, or brick-colored, sometimes only the margin 
remaining yellow. Exterior filaments much the longest, deep red ; interior ones paler, shorter ; 
pistil pale yellowish, thickened below the middle, as in almost all the species of this genus ; 
stigmata united into a small subconic head. 
Fruit ovate, or sometimes globose, umbilicus shallow, spines on the pulvilli numerous, 6-12, 
usually short, 1-4, sometimes 6 lines long. Seeds about 3 lines in diameter, sometimes larger, 
in one form much smaller, mostly irregular, twisted, angular, much compressed, with a broad 
and thick but rather acutish rim. Embryo of different shapes, conform to the shape of a seed, 
always with a small albumen. 
The following forms, we think, must be included under this species, though the whole history 
of most of them is not known ; some of them may not even be constant varieties. 
a. rufispina : articulis orbiculatis s. transversis setis parcis rufescentibus, aculeis radialibus 
6-8 albidis rufo-variegatis, interioribus validis fuscis apice pallidioribus, 2-4 deflexis, singulo 
patulo s. suberecto robustissimo ; bacca ovata.—(Plate XIV, fig. 1-3.) 
This is the shortest form of our species, and greatly deserves Nuttall’s original name ferox ; 
It was collected on rocky places on the Pecos ; Dr. Hayden has also sent it from the Yellow¬ 
stone, and it no doubt is met with in all the intervening territory. Joints 2-3 inches in diame¬ 
ter, pulvilli 4-5 lines apart; bristles fewer, but longer and darker than in other forms ; central 
spines 1|—2 inches Jong ; fruit 1 inch long, half as thick, with shallow umbilicus, about 30 
pulvilli, spines on the upper ones 4-6 lines long. Seeds 2|-3 lines in diameter. 
/?. platycarpa : articulis obovato-orbiculatis, setis parcis stramineis, aculeis exterioribus 
