CACTACEZ OF THE BOUNDARY. 209 
brick-red or yellow, as in the allied species ; the only other purple one of our Platopuntie is O. basilaris, which is of a 
yet purer and deeper purple color. Fruit unknown, Seeds have been sent which have germinated and produced 
plants which already after the first year showed the characteristic glaucous hue and the tuberous roots. These seeds 
also differ from all our other Opuntia seeds by their great thickness, and their remarkably narrow but thick and obtuse 
margin. They are only very slightly notched at the hilum, and i a diameter of 1.7—2.0 lines, with a thickness of 
1,2 line. 
8. O. MacroruHIzA, E. in Plant. Lindh., from between San Antonio and Austin CPanthetmnse), " iieP BEY well 
perma by its large tuberous roots, mbich even the young seedlings very soon begin to show without these 
is hardly distinguishable from 0. Ce ty E. of the Mississippi valley. I find the flower se an ee 
pe the stigmata always 5. (Tab, LXIX.) 
9. O. RUFIDA, sp. nov. : erecto-patula ; articulis late obovatis seu suborbiculatis pubescentibus ; foliis e basi 
lata subulatis longe acuminatis ; pulvillis confertis griseo-villosis setas rufidas graciles numerosissimas penicillatas 
gerentibus inermibus ; floris flavi ovario obovato pulvillis 40-50 instructo ; sepalis tubi 20-30, exterioribus lineari- 
lanceolatis acuminatis, interioribus obovatis —— ; petalis (8 ?) orbiculato-obovatis obtusis erosis seepe mucronu- 
latis ; stigmatibus sub-7 abbreviatis in capitulum globosum congestis. 
n about Presidio del Norte, on he Rio Grande, on rocks and mountains (Bigelow) ; in the lower [52] 
valley of the Nazas, southeastern Chihuahua (Gregg). Flowers in May. — Stems 2-4 feet high ; joints 2-6 inches 
long, pale green, sae any red or colored spots surrounding the pulvillus, as is said to be constantly the case in the 
allied O. puberula and O. decumbens ; leaves apa patie: acuminate, 2} lines long, about twice the length of the 
axillary ons pulvilli thickly tomentose, and with an abundance of very delicate brown-red bristles, almost entirely 
_ covering the surface of young or not fully-grown Ams in adult ones about 4 lines apart. The flower described above 
was obtained south of the Rio Grande, in the sia de Mapimi; ovary 10 lines long, flower 2} inches in diameter, 
stigmata (green?) about 1 line in length. This species is nearly allied to 0. microdasys, which is common in cultiva- 
tion, and specimens of which from Saltillo I a been able to compare. Our plant has more rounded and larger 
joints, more distant pulvilli, which bear reddish-brown (not yellow) bristles and longer leaves. From 0. puberula, 
which seems to be yet nearer allied to it, it differs by the absence of spines, larger eat ete. Mr. Schott has noticed 
a pubescent Opuntia on the dividing ridge of the California Cordilleras, near the bo y line, and a suberect species 
in the Santa Cruz valley, in Sonora, about 3 feet high, both without spines. It is Spribans to form any opinion 
where they belong, as no specimens have been saved. 
10. O. BastzaRis, E. & B. in Pacif. R. R.: found by Mr. Schott in the Gila valley, and up the eastern slope of 
the California mountains. Flowers in May. 
. O. ARENARIA, sp. nov.: diffusa, adscendens ; radicibus crassis elongatis seepe stoloniferis ; articulis minori- 
bus obovatis crassis tumidis seu ibccuibcaian tuberculatis nitide virentibus ; foliis minutis pulvillo vix longioribus ; 
pulvillis enemies parce albo-tomentosis setas plurimas gracillimas pallidas demum in articulis vetustis numerosis- 
simas pulvinatas fulvas gerentibus, omnibus fere armatis; aculeis superioribus 1-4 sepe subangulatis, summo 
validiore soot albido seu fusco-variegato, ceteris brevioribus divergentibus seu deflexis albidis ; aculeis inferiori- 
us 2-6 brevibus setaceis albis radiantibus; floribus sulphureis; ovario obovato pulvillis 20-30 setosis aculeolatisque 
iii: sepalis tubi 12-14, inferioribus late obovatis cuspidatis, — obtusis ; petalis sub-8 obcordatis seu 
bus 
emarginatis spe mucronatis ; stigmatibus 5 mucronatis viridi n capitulum collectis ; bacca oblonga ovata 
aculeolis <n gia armata ; anibities infundibuliformi ; seminibus sidets irregularibus late crasseque marginatis. 
(Tab. LX XV. fig. 1 
Sandy “nates “ot the Rio Grande near El Paso (Wright). Flowers in May. — Roots 3-5 lines thick, at last 
ligneous, far spreading in the loose sand, and sometimes stoloniferous, which I have also noticed in some forms of 
riensis ; stems spreading 2 or 3 feet, 3-1 foot high ; joints 14-3 inches long, 1-2 inches wide, often terete or 
father oval, or clavate (a specimen before me is 23 inches long and ? inch thick), ind always strongly tuberculate ; 
leaves about a line long ; pulvilli smaller than in 0. fragilis, very sparingly tomentose, very bristly, the tawny bristles 
of the old joints covering almost the whole surface. fe and longer spines 9-15 or even 18 lines long, white, with 
a yellow tip, or brown, ella, or reddish at base and tip; other spines 2-6 lines long, white. Flower 2-2} inches 
in diameter ; ovary 9-12 lines long; filaments greenish-yellow ; stigmata nearly 2 lines in length, Fruit dry, 
10-14 lines long, contracted at top, with a deeply immersed umbilicus, and with spines of 1-5 lines in length. Seeds 
23-3 lines i in pees 
is species is necthy allied to the northern O. fragilis, but is distinguished by the larger and more strongly 
tuberculated joints, smaller pulvilli set with numerous bristles, the longer and slenderer spines, and the spinose fruit. 
27 
