lines long; spines 1 - X£ inches long, hiding the whole plant with 
their lustrous sheaths. Flower about one inch or less in diameter. 
Fruit fleshy, 1-1£ inches long, usually sterile. Seeds smaller than 
in any other Opuntia examined, 1 - lines long. 
40. O. Bigelovii, E. in P. R. R.: ramis erectis adscendentibusve ; 
articulis ovato-cylindricis pallide virescentibus congestis; tuberculis 
subhemisphsericis depressis confertis; aculeis 6-10 robustioribus et 
totidem gracilioribus inferioribus; ovario tuberculato; bacca tuber- 
culata subinde (sterili ?) aculeolata semmibus,parvis. 
On Williams’s River, of the Californian Colorado. — Stem 3-4 
inches thick and 10- 12 feet high; the branches forming a dense 
contracted head, with joints 2-6 inches long; tubercles 3-4 lines 
long ; larger spines about an inch long, smaller ones 4-7 lines long. 
The three foregoing species represent this subsection west of the 
California mountains, and east of them both south of the Gila and 
north of it, and seem to be well distinguished from one another by the 
characters indicated. 
fff Cristata: frutescentes vel arborescentes: articuli cylindrici: tu- 
bercula plerumque cristata prominula: flores purpurei: baccse in- 
ermes seu rarius aculeatse. 
41. O. Whipplei, E. & B. in P. R. R. : caule erecto seu rarius 
subprocumbente divaricato-ramoso ; articulis cylindricis ; tuberculis 
ovatis confertis ; aculeis brevibus cinereo- seu stramineo-vaginatis, 1 - 
4 majoribus, 2-8 brevioribus deflexis vel radiantibus ; flore rubro ; 
bacca subglobosa tuberculata flava inermi; seminibus regularibus. 
Var. a. ljevior : humilior, aculeis paucis deflexis. 
Yar. /3. spinosior: elatior, aculeis plurimis radiantibus. 
From Zuni westward to Williams’s River (a.), and south of the Gila 
(/3.): fl. in June. — The first state is from a few inches to 3 - 6 feet 
high ; the second forms'small trees 8-10 feet high. Joints f inch 
in diameter; tubercles about 5 lines long; spines very variable, be¬ 
tween 3 and 9 lines long. Flower (of var. /3.) l£ - 1^- inches in di¬ 
ameter. Fruit about an inch long. 
42. O. arborescens, E. in Wish Rep. (O. stellata , Salm.) : arbo- 
rescens; ramis verticillatis horizontalibus vel pendulis ; articulis verti- 
cillatis cylindricis; tuberculis cristatis prominentibus ; aculeis 8-30 
stellato-divaricatis; flore purpureo magno; bacca subhemisphserica 
tuberculato-cristata flava inermi; seminibus regularibus. 
