60 UNITED STATES AND MEXICAN BOUNDARY. 
pretty species of Opuntia bears a name which has been often mentioned in these pages, and 
which is forever inseparably connected with the botany of our Southern boundary. 
26. O. ARBUSCULA, (sp. nov.): caule erecto arborescente dense lignoso apice ramosissimo capi- 
tato; ramis divaricatis elongatis teretibus etuberculatis; articulis junioribus lete viridibus 
leviter tuberculatis ; tuberculis oblongo-linearibus depressis ; pulvillis magnis orbiculatis albo- 
tomentosis ; setis parcis gracillimis penicillatis ; aculeis singulis (seu subinde binis lateralibus) 
porrectis demum deflexis stramineo- seu fulvo-vaginatis, rarius une alterove breviore inferiore 
deflexo adjecto ; flore flavo-virescente; ovarii clavati pulvillis 16-18 albo-tomentosis vix setosis ; 
sepalis tubi sub-8 orbiculatis cuspidatis seu mucronatis; petalis sub-5 spathulatis, staminibus 
extus in staminodia latiora subulata transeuntibus ; stigmatibus 5 brevibus erectis. 
On the desert heights, near Maricopa village, on the Gila, Schott: fl. in June.—A truly 
arborescent species, 7-8 feet high, with a solid, ligneous trunk, 4-5 inches thick, smooth 
green bark, and a top formed by the numerous slender and divaricate branches ; ultimate joints 
2-3 inches long, about 4 lines in diameter ; tubercles flat and indistinct, about 6 lines long ; 
spine 9-12 lines long. Ovary, in my specimen, 10 lines long and only 4 lines in diameter, 
without any spines ; but the fruit is described by Mr. Schott as “ bristly, crowned by the per- 
sistent flower.’’ Flower apparently nearly 14 inch in diameter; petals few, 9 lines long and 
4 lines broad, greenish-yellow, tinged with red. Stamina and staminodia (perhaps what I con- 
sider so are but the broader filaments of the exterior fertile stamens) finally breaking off near 
their base, leaving a rough surface. The name of this species indicates a small tree, 
27. O. rrutescens, E. in Pl. Lindh. was collected abundantly in all western Texas and 
southern New Mexico. For a fuller account and a figure, see Engelmann and Bigelow’s paper 
on the Cactacee of Captain Whipple’s Pacific Railroad Exploring Expedition Report. 
28. O. TesseLiata, E, in Pacif. R. R. (O. ramosissima, EZ. in Sill. Journ. 1852).—This curious 
species was first noticed by Dr. Parry, and described, as above cited, in an account of his Cali- 
fornian Cactacee, under the name of O. ramosissima, which being deemed an improper name in 
a section where all could claim it with equal, and some with greater justice, it was changed in the 
account of Dr. Bigelow’s plants, who brought specimens of the wood, the branches, and the 
fruit. Mr. Schott, the third botanist who collected it, was fortunate enough to find the flowers. 
Living plants are yet a desideratum in our gardens. ! 
This species grows in arid sandy soil, from the Sierra Madre south 9f the Gila to the lower 
Colorado, Bill Williams’s fork, and the Californian Mountains. Mr. Schott found it in September 
with flower and ripe fruit. The flower is purple, about 6 lines in diameter ; the clavate ovary is 
of the same length, and bears 40 or 50 very tomentose but searcely spiny or bristly pulvilli; the 
5 petals are almost orbicular ; the exterior filaments are broad and persistent (sterile stami- 
nodia?); 5 stigmata short and erect. The fruit resembles very much those of the clavate 
Opuntice ; it is 9 or 10 lines long, dry, ovate, and contracted above ; the narrow and deep umbi- 
licus contains the remains of the flower, the above-mentioned broad filaments being most con- 
spicuous ; externally it is covered with.a profusion of hair-like flexuous bristles of a red ‘brown 
color, 2-3 lines in length, mixed with dense wool. Seeds thick, with-a broad spongy pri 
sire, 1.8-2.0 lines in diameter. ' Mr. Schott. collected in May other greenish-yellow flowers, from 
similar bushes, which he considers as of a distinct variety ; the ovary in these- flowers appears 
elongated, and is probably sterile, and would have become persistent and proliferous, as we find 
it'in ba stance Opuntic ; "80° that this green-ilowered. form probably: is: not- a variety of our 
i. 
