CACTACER. 51 
parce tomentosis vix setosis; aculeis brevibus cinereo s. stramineo vaginatis, 1—4 majoribus 
divaricatis, inferiore longiore deflexo, minoribus 2-8 solum ad inferiorem pulvilli marginem 
deflexis s. undique radiantibus ; flore rubro, ovario ovato tuberculato pulvillis 20-30 tomentosis 
setas stramineas et aculeolos paucos mox deciduous gerentibus stipato sepalis tubi sub-8 orbicu- 
latis cuspidatis, petalis 8-10 spathulatis cuspidatis; bacca subglobosa leviter tuberculata sub- 
carnosa flava inermi ; umbilico infundibuliformi seminum subregularium commissura lineari. 
a. LEVIOR humilior, aculeis brevioribus paucioribus seminibus minoribus. 
B. SPINOSIOR elatior aculeis plurimis longioribus seminibus majoribus. (Plate XVII, fig. 1-4.) 
From the elevated country about Zuñi to the head of Williams's river, at first seen only 8-15 
inches high, subprostrate, afterwards 20-30 inches, and sometimes even 5-6 feet high. Var. f. 
was found by Mr. A. Schott south of the Gila river, and he also discovered the flower of this 
plant, which, like the flowers of all the other new species, remained unknown to us, unless 
winter remains were picked up here and there. Ligneous skeleton tubular, with small meshes, 
dense at base of stem ; joints elongated, 2-4 inches to a foot long, 3 or $ of an inch in diameter ` 
tubercles ovate or sometimes almost rhombic, about 5 lines long; spines very variable in number, 
sometimes only with 1 larger and 2 or 3 smaller ones; in other instances, especially in Var. 3. 
with 12 or 14 ; spines 3-9 lines long, bristles few, generally only on older joints; flowers 14-14 
inches in diameter ; ovary 6-9 lines long with 20 or 25 pulvilli; fruit about 1 inch long, a little 
less in diameter, somewhat fleshy and sweet, with 25-35 not very prominent tubercles; seeds 
with linear or almost linear commissure, 13-1$ lines in diameter; cotyledons regularly incum- 
bent or sometimes oblique. The seeds of f. are 2 lines in diameter. 
This is easily distinguished from all the allied species of the slender elongated branches, the 
short, crowded tubercles, and the short spines. We have dedicated this Opuntia, characteristic 
of the desert mountains under the 35th degree, between the Rio Grande and the Colorado, to 
Captain A. W. Whipple, the commander of the expedition who, by his zealous and liberal co- 
operation, afforded every facility in his power in the various collections of natural history- 
(Plate XVII, fig. 5—6, and Plate XVIII, fig. 4.) 
23. O. ARBORESCENS, Englm.: found first 200 miles east of the Pecos, and from there abun- 
dantly as far west as Zuñi, where other cylindric Opuntic take its place. In this region it does 
not grow higher than 5-8 feet, and can scarcely be called arborescent ; it is always well charac- 
terized by the verticillate often somewhat pendulous branches, the cristate-tuberculate spineless 
fruit, and the smooth seeds with a distinct and broadly linear commissure. Seeds of specimens 
collected at Zuñi smaller than others, ouly 14 line in diameter. 
24. O. ACANTHOCARPA, (sp. nov.): caule arborescente erecto reticulato-lignoso, ramis adscen- 
dentibus divaricatis articulis cylindricis tuberculatis pallide virescentibus, tuberculis oblongo- 
linearibus pulvillis ovato-orbiculatis breviter tomentosis vix setosis, aculeis numerosis s. plurimis 
(8-25) stramineo-vaginatis undique porrectis, stellatis; bacca subglobosa late umbilicata 
tuberculata ; pulvillis 12-15 tomentosis parce setosis aculeolis validis 8-10 munitis; seminibus 
magnis muetangulis late commissuratis. (Plate XVIII, fig. 1-3.) 
On the mountains of Cactus Pass, about 500 miles west of Santa Fé. Stout, stem 5-6 feet 
high, wood forming a hollow reticulated tube, solid at base; branches few, never verticillate, 
separating at acute angles; joints 4-6 inches long, 1 inch in diameter, tubercles 9-10 lines long; 
pulvilli in some with one central and 6 or 8 exterior spines, in others with 3-7 interior and 
10-20 exterior stellately radiating spines. Central spines 1-1} inch, exterior 4-10 lines long, 
with a yellowish or brownish sheath. Fruit 1 inch long with a large but not deep umbilicus, 
and 12-15 rather shallow tubercles ; spines of fruit stout, 3-6 lines long, stouter and more 
crowded toward the top of the fruit. Seeds unlike any other of our Opuntie, 24-3 lines in 
diameter, with rather broad commissure, often spongy on the margin, and on the sides with 
. many even or concave faces separated by sharp ridges. 
LI 
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