stigmatibus 8 in capitulum congestis; bacca obovata late umbilicata 
(sicca?); seminibus magnis crassis subregularibtis. 
On Williams’s River, the Colorado, and the Mojave, and down to 
the Gila : fl. April and May. —Habit very different from any other 
of our Opuntia; the stout obQvate or fan-shaped joints (5 -8 inches 
long) originate from a common base, forming a sort of rosette. 
Leaves only one line long, 4-6 lines apart; pulvilli red-brown, 
somewhat immersed. Flower about 2 \ inches in diameter; ovary 
with 40 - 60 pulvilli. Fruit apparently dry, thereby approaching the 
next section. Seed 3 lines in diameter, 2 lines thick, 
Mr. Schott has observed, on the dividing ridge of the California 
mountains, west of the mouth of the Gila, and again in the Santa 
Cruz Valley, Sonora, a very similar but suberect species, 3 feet 
high, spineless* inclined to assume a purplish hue, which he seems to 
have confounded with O. basilaris. Can it be O. rufida , or is it an 
undescribed species ? 
§ 6. XerocarpecB: diffusse : articuli suborbiculati vel tumidi: aculei 
plurimi: bacca sicca aculeolata: semina eburnea, magna, plerum- 
que latissime marginata. 
**Articuli compressi suborbiculati. 
22. O. hystricina, E. & B. 1. c. i diffusa; articulis obovato-orbi- 
culatis; pulvillis subconfertis setas pallidas rutilasve gerentibus, omni¬ 
bus armatis ; aculeis 5-8 superioribus validis elongatis angulatis seu 
tortis patulis vel deflexis, inferioribus 5-7 gracilioribus radiantibus; 
bacca ovata aculeolata, umbilico planiusculo ; seminibus maximis. 
West of the Rio Grande, to the San Francisco mountains. —Joints 
3-4 inches long ; pulvilli 5-6 lines apart, unusually large ; longer 
spines 1J - 3 and-even 4 inches long, brownish ; lower radiating ones 
white, 4-9 lines long. Fruit an inch long ; upper pulvilli with 4-6 
bristly spines. Seeds 3J lines in diameter, among the largest in this 
genus. 
23. O. Missotjriensis, DC. (Cactus ferox, Nutt. Gen.) : prostra¬ 
ta ; articulis obovatis vel suborbiculatis tuberculatis ; foliisf minutis; 
pulvillis subconfertis stramineo-setosis, omnibus armatis; aculeis 5- 
10 exterioribus radiantibus setiformibus albidis, 1-5 interioribus ro- 
bustis albidis seu rufescentibus ; floris flavi intus aurantiaci ovario obo- 
vato vel subgloboso spinuloso; stigmatibus *5-10 viridibus; bacca 
gpinosa, umbilico piano ; seminibus magnis irregularibus. 
