222 ADDITIONS TO THE CACTUS-FLORA OF THE UNITED STATES. 
nearly the same base, and are covered in spring (March and April) with a profusion of rose-colored or purplish flowers, 
often 150 on one plant. The ovary is described as somewhat tuberculate, but sometimes almost smooth. The fruit is 
dry when ripe. Seed large and thick, as in the figure above cited. 
O. HystRicIna, Engelm. and Bigelow, 1. c., p. 54, tab. 15, fig. 5-7, and tab. 23, p. 15; Synops. Cact., p. 43. 
ommon from the Colorado to the Rio Grande. The form sollceted by Dr. Newberry, and named in es notes 
“hairy-spined Opuntia,” has fewer, shorter, and usually straighter spines than the specimens figured and described in 
Lieutenant Whipple’s Report; the larger ones are also angular and erect, and by these characters distinguished from 
the nearly allied Opuntia Missourtensis. However, Mr. Fendler’s specimens from Santa Fé (the flowers of which were 
inadvertently distributed with No. 276, O. pheacantha, but are easily distinguished by the spinulose ovary) seem to 
be intermediate between the two, and may make it necessary to unite them 
Dr. Newberry’s specimens have 1-5 larger spines, 1-1? inch long, nearly erect, and about 5 smaller deflexed 
ones below, with a few very small ones above. Flower nearly 2 inches in diameter; ovary with 20-25 tomentose 
pulvilli, each with a short slender leaf (sepal) less than 1 line long, and 5-12 bristly spines of very different 
lengths; the interior sepals are obovate cuspidate petals, obcordate, orange-yellow ; 5 erect green stigmata, forming a 
compact h 
O. ECHINOocARPA, Engelm. & Bigelow, 1. c., p. 40, tab. 18, fig. 5-10, and tab. 24, fig.8; Mex. Bound. Rep. II., 
p- 56; Synops. Cact., p. 49. In the Mojave valley, and common on the Colorado. Begins to flower the end of 
March. The specimens obtained are low, with many short branches, much of the habit of the clavate Opuntie, but 
distinguished from them by the sheathed spines and the reticulated wood peculiar to the cylindroid Opuntie. The 
ovary is 6-8 lines long, with about 20 pulvilli, bearing thick ovate leaves, abruptly narrowed into a subulate point, 
1-2 lines long, and in their axils in a white tomentum 6 or 8 sheathed spines, the large ones 6-8 lines long. 
greenish-yellow flower when fully open is 14 inch wide; petals spatulate, rounded or emarginate, denticulate, the 
exterior ones mucronate; stigmata 5-6, large and thick, and apparently yellow. 
O. ARBORESCENS, Engelm. in Wisliz. Rep. N. Mex., note 5; Mex. Bound. Rep. IL. p. 58, tab. 75, fig. 16-17; 
Pacif. Rail. Rep. IV., tab. 17, fig. 5-6, tab. 18, fig. 4, and tab. 24, fig. 12 ; Synops. Cact., p. 51. Common in western 
New Mexico. 
X. ADDITIONS TO THE CACTUS-FLORA OF THE TERRITORY OF THE 
UNITED STATES. 
FroM THE TRANSACTIONS OF THE ACADEMY OF ScrEeNcE or Sr. Lovis, Vol. II. 
Sixce my “ Synopsis of the Cactacee of the United States”! was published, Dr. J.S. [197] 
Newberry, attached to Lieutenant Ives’s Expedition to the Colorado River, 1857-58, has 
elucidated more fully the natural history of several species heretofore only imperfectly known? In 
the same year (1858) and the following one my brother, Henry Engelmann, geologist to the Expe- 
dition sent under Captain James H. Simpson, U. S. Topographical Engineer, to explore the best 
emigrant routes through the interior of Utah, discovered in that interesting country a number of 
new forms, which were placed in my hands for examination. My report on them, illustrated by 
several plates from the hands of our skilful artist, Mr. P. Reetter, was in due time sent to the Depart- 
ment; but the necessities of the country not permitting the official publication, I have received 
permission to communicate the substance of my investigations. 
1. Mamrinarra vivrpara, Haw. Engelm. Synops. Cact., p. 13. In the South Pass, and on Sweetwater River ; 
no specimens of this wide-spread species have turned up from the other side of the great mountain-chain. 
2. Ecurtnocactus Srpsont, sp. nov.: e basi turbinata simplex, subglobosus seu depressus, mamilliferus ; 
tuberculis laxis ovatis oblique truncatis axilla nudis; areolis ovatis seu ovatolanceolatis, eesti albo-villosissimis 
mox nudatis; aculeis exterioribus sub-20 tenuibus rigidis rectis albidis, interioribus 8-10 erecto-patulis robustioribus 
1 Proc. Amer. Acad. Arts and Sci., Vol. III. pp. 259-314, and 344-346, Nov. 1856. ; 
2 See my account in Lieutenant Ives’s Colorado River Exploring Expedition; Botany, pp. 12-14. Washington, 1861. 
