CACTACEZ OF THE BOUNDARY. 211 
1-1} inch long; flowers pessoa sie externally tinged with purple, 2 or 24 inches in diameter; pulvilli of the 
ovary over a line in diam white-tomentose, supported by subulate leaves (2 lines long) bearing short w 
bristles and reddish eet : pene sepals oblanceolate, cuspidate, red-brown, interior ones with yellow and oa 
petaloid margins ; petals yellow, with red tips ; fruit not as large but even more spiny than in the specimens from 
El Paso. 
This species also has been named in honor of Colonel W. H. Emory, who, in his different expeditions to the 
extreme southwestern parts of our territory, always exerted himself for the advancement of our knowledge of the 
natural history of these regions. 
. QO. Scuorri, sp. nov.: articulis breviter clavatis adscendentibus ; tuberculis elongatis ; pulvillis pauci- 
setosis ; aculeis scaberrimis cialis, interioribus 4 cruciatis, superiore triangulato erecto, ceteris re ie ae 
planis subtus convexis, inferiore latiore ; aculeis exterioribus 8-10 radiantibus valde inaqualibus ; obovat 
clavata, aed villis 35-40 setas suberectas riege at paucos gerentibus ; seminibus angulatis rostratis ‘aati: 
commissura lineari indistincta. (Tab. LX XIII. fig. 1-3. 
‘Abend on the arid hills near the Rio Grande; between the San Pedro and Pecos rivers (Wright, Schott). — 
e specimens gathered in July and September were all in fruit. Joints 2 inches, tubercles 8-9 lines long ;. pulvilli, 
even in the oldest joints, with few bristles. Spines rougher than in any other allied species, red, the broader onés 
with a white margin, 13-2 inches long; smaller radiating spines 4-9 lines long, almost. surrounding the inner one. 
Ovary with white-tomentose pulvilli ‘eal short bristles ; those in the fruit ne a little longer, but are confined to 
the upper half of the pulvillus and are erect, while in all the allied species they are much more numerous and 
stellately spread in all directions. Seed a little over 2 lines in the transverse ‘dies cotyledons in all [55] 
the seeds examined oblique. Dedicated to one of its discoverers, whose name I have often had occasion to 
mention. 
Dr. Gregg has sent a similar plant from San Luis Potosi, Mexico, which, though growing 7 or 8 degrees farther 
south, I must consider the same as O. Schottii. Its joints 2 inches long; tubercles 10-12 lines long; 4 central 
spines ancipital or triangular, 12-20 lines long, much less rough, 8-12 exterior spines of very different sizes. 
(Tab. LXXIII. fig. 4 
RAHAMI, sp. nov.: radicibus crassis fusiformibus ; articulis breviter clavatis adscendentibus lete 
viridibus ; pasa oblongis ; foliis e basi ovata abrupte acuminatis ; pulvillis albo-tomentosis setas demum 
numerosas ngatas rigidas gerentibus; aculeis gracilibus scabris rubellis demum cinereo-fuscis, Aggie 4-7 
Oe dette oes ni 9 seu 4-angulatis seu rarius compressis, exterioribus 4-6 multo minoribus re flavo ; 
ovarii pulvillis sub-30 albo-tomentosis setosis ; bacca ovata setosissima; seminibus regularibus vix (eaasaats com- 
missura lineari indistincta. (Ta 
Sandy soil in the bottom of the Rio Grande near E] Paso, and for a distance of about one hundred miles along 
the river (Wright, pea Flowers in June. — Roots often 6 inches long and an inch thick, tapering, single or 
divided ; joints 14-2 inches long, ? or at most 1 cok in diameter ; tubercles 6-7 lines long ; leaves similar to those of 
. vulgaris, short and thick, nearly a line in diameter at base and about twice as long ; larger spines 13-2 inches long 
and spreading, scabrous, slenderer than in any allied species. Flowers apparently 2 inches in Fs and, like the 
fruit, very similar to Sine of 0. clavata. Seeds 2.5-2.8 lines long, with a linear and often very indistinct commissure ; 
cotyledons i in the seeds examined regularly incumbent. 
is species, peculiar to an interesting part of our boundary, has been named in honor of the pi tan who 
was for a time chief of the scientific corps of the Commission, and by whose orders this, with many other species of 
Cacti, has been sent to me. 
16. O, BULBISPINA, sp. nov.: radicibus fusiformibus ; articulis parvis ovatis vix clavatis sepius ex apice 
proliferis fragilibus ; pulvillis ares: setosis, junioribus laxe villosis ; aculeis ae scabrellis basi bulbosis, 
interioribus 4 cruciatis, inferiore longiore, exterioribus 8-12 radiantibus. (Tab. LX XIII. fig. 
Near Perros Bravos, north of Saltillo (Gregg). — Spreading masses 2-4 ey in diameter ; fea 9-12 lines long, 
6 lines in diameter, often proliferous at the upper end; tubercles 3-4 lines long; interior spines 4-6 lines, exterior 
ones 13~3 lines in length. This species has the subcylindric joints, the reticulated ligneous texture, and the scabrous 
spines of the clavate Opuntia, but its mode of ramification is rather different, and the form of the joints is more ovate 
than clavate. Perhaps it belongs rather to Prince Salm’s section Glomerate, and near O. pusilla from South America. 
§ 2. Cylindrice. 
Stems ascending or usually erect, much branched ; joints cylindric or tumid, tuberculate or sometimes almost 
smooth. The ligneous tissue is compact, and either (in spec. 17-24) forms a jetioalated hollow tube, in which the 
meshes correspond with the tubercles, and which by age becomes more and more solid and massive, or it is 
(in spec. 25-28) reticulated only when quite young, and soon becomes quite dense. The spines are almost always 
terete, and are always covered with a loose glistening sheath. Flowers purple or rarely yellow, large, or usually 
