CACTACEH OF WHIPPLE’S EXPEDITION. a7] 
umbilicus on the shallow fruit gives it the appearance of a saucer, and the seeds find their place more around the edge 
of the umbilicus than in the body of the fruit. Spines on fruit from 4 to 10 lines long. Seed 2 lines or more in 
diameter, with a broader commissure than any of the allied species ; cotyledons always ; all the specimens examined 
regularly accumbent or parallel (the only species, so far, where this regularly is the case) ; albumen unusually large. 
O. serpentina, from San Diego, is very nearly allied to our species, but seems sufficiently distinct by its elongated 
cylindric joints and different growth. 
vil, Engelm. : caule arborescente erecto crasso reticulato-lignoso, ramis erectis adscendentibusve 
numerosis caads ineins demum refractis, articulis ovatis s, ovato-cylindricis tumidis lete s. pallide viridibus 
fragilibus ; tuberculis subhemisphericis depressis confertis ; pulvillis immersis Ovatis setas pallidas penicillatas et 
aculeos 6-10 robustiores pallidos stramineo-vaginatos, 3 deflexos, ceteros divergentes et 6-10 graciliores inferiores 
radiantes gerentibus; ovario tuberenlis plurimis stipato parce aculeolato ; bacca ovata profunde umbilicata tubercu- 
lata eg immersos 60-70 setigeros inermes s. aculeolos sub-3 vaginatos gerente; seminibus parvis. (Plate XIX. 
gs. 
On Williams’s River, a branch of the Colorado ; 10-12 feet high, stem ? inch in diameter ; skeleton forming a 
large hollow tube, much reticulated with numerous small roundish or somewhat rhombic meshes in 13 or 21 spiral 
rows ; branches forming a dense head. Younger joints erect, adpressed very fragile, often shaken off by the wind and 
covering the soil around, taking root everywhere, or sticking to the clothes of the passers-by like burrs ; the joints on 
the older part of the stem are often. persistent and reflexed, becoming withered and brown. Joints 2-6 inches long, 
1-2 inches in diameter, light fresh green, covered with the small, almost hemispherical and not very prominent tubercles, 
which are 3-4 lines long, and arranged mostly in 13 spirals ; the areola is immersed at the apex of the tubercle, and 
surrounded by an elevated paler or almost whitish ridge, having the appearance of 2 lateral glands. Larger spines 
about 1 inch long. Flower or complete fruit not seen n ovary or young fruit before me is clavate, 1 inch long, and 
has a few spines on the pulvilli. Some empty (siexile ?) fruits brought home are oval, 13-1}? inches long, 1 inch in 
diameter, strongly tuberculated, and spineless ; others again are even larger, with more numerous tubercles, and the 
pulvilli beset with 3-6 sheathed spines 4-7 lines long; these are evidently undergoing a change into joints. Prolife- 
rous seeds, said to be small; but most unfortunately the specimens were lost, so that we were unable to compare 
them with those allied species found farther south (0. fulgida) and on the Pacific coast (O. prolifera). Our plant 
is distinguished from these forms by its short tubercles, immersed pulvilli, and large tuberculated and somewhat 
spiny fruit. 
[I have thought proper to consecrate this remarkable species, so conspicuous in its desert wilds, to my colaborer 
Dr. J. M. Bigelow, through whose intelligent exertions and indefatigable assiduity so many new Cactacez, described 
in this report, have been discovered and brought home. — G. E.] 
22. O. WHIPPLEI, sp. nov.: caule erecto s. rarius patulo s. subprocumbente, reticulato-lignoso, divaricato 
oso, articulis cylindricis ; Saris atin ovatis confertis, pulvillis pulvinatis parce tomentosis vix setosis; [51] 
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 deciduos gerentibus stipato sepalis o sub-8 
orbiculatis cuspidatis, petalis 8-10 spathulatis cuspidatis ; bacea subglobosa leviter tuberculata subcarnosa flava inermi; 
umbilico infundibuliformi seminum subregularium commissura lineari. 
a. LEVIOR, humilior, aculeis brevioribus paucioribus, seminibus minoribus. . 
8. sPINosIor, elatior, aculeis plurimis longioribus, seminibus majoribus. (Plate XVII. figs. 1-4.) 
From the elevated country about Zufii to the head of Williams’s River ; at first seen only 8-15 inches high, sub- 
prostrate, afterwards 20-30 inches, and sometimes even 5-6 feet high. Var. 8. 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, } 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. 8., with 12 or 14; spines 3-9 lines long ; 
bristles few, generally only on older joints. Flowers 13-1} 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 promi- 
nent tubercles. Seeds with linear or almost linear commissure, sede lines in diameter ; cotyledons regularly 
incumbent or sometimes oblique ; the seeds of 8. are 2 lines in diamete 
This is easily distinguished from all the allied species by the aie elongated branches, the short crowded 
— and the short spines. We have dedicated this Opuntia — characteristic of the desert mountains under the 
th degree, between the Rio Grande and the Colorado—to Captain A. W, Whipple, the commander of the expedition, 
