208 CACTACEZ OF THE BOUNDARY. 
fusco-atris sursum pallidioribus ; flore flavo; ovario brevi pulvillis sub-20 tomentosis et fulvo-setosis versus superiorem 
ovarii partem congestis ; sepalis tubi sub-13 oes late oblanceolatis ceteris late obovatis cuspidatis ; petalis 
8-10 late obovatis obtusis submucronatis ; stigmatibus 8 erectis ; bacca cuneato-pyriformi late umbilicata vix pulposa ; 
seminibus plerumque majusculis sub-regu RE crasse ener (Tab. LXXV. fig. 9.-13.) 
Var. a. NIGRICANS: obovata, viridior; pulvillis magis approximatis; aculeis brevioribus acute angulatis 
nigricantibus. 
r. 8. BRUNNEA: obovata, glaucescens ; pulvillis remotis ; aculeis longioribus obtuse angulatis infra brunneis. 
long the Rio Grande near Santa Fé, var. a. (Fendler) ; var. 8. common about El Paso, on the sandy ridges in 
the immediate valley of the river (Wright).— The northern plant has been correctly described in “ Planta Fend- 
lerianz,” with the exception of the flower, which probably refers to O. Missouriensis, or some allied species. The 
variety from El Paso has remarkably thick and glaucous joints, which in fall and winter often assume a purplish hue ; 
they are commonly 4 or 5 inches long and 2}-3 inches wide, the largest ones were 7 inches long and 4} inches broad, 
sometimes they are more orbicular and shorter; leaves 2}-3 lines long, thick in proportion ; pulvilli 1-13 inch apart, 
with dirty yellowish or brownish bristles, only the lowest ones without spines ; spines usually 2-4, sometimes 4 or 5, 
and even more, in one bunch, 1-2 or sometimes 24 inches long, terete or more or less flattened, but without sharp 
angles, often striate, light or dark brown below, whitish above, lower spines often entirely whitish. Flower 
2}-21 inches in diameter ; ovary 10 lines long, 8 lines in diameter. Fruit 1j}-1} inch long, with the lower part 
contracted, solid and seedless ; umbilicus sithen. shallow. Seeds very variable, ee over 2 lines in diameter, but 
sometimes smaller, 
O. TENUISPINA, sp. nov. : diffusa seu adscendens; articulis mediis seu majusculis obovatis basi attenuatis 
lete viridibus ; foliis gracilibus subulatis parvis, pulvillis subapproximatis setas breves graciles fulvas rufasve gerenti- 
bus, plerisque armatis seu inferioribus inermibus ; aculeis singulis binisve teretiusculis rectis gracilibus flexilibus 
albidis non raro basi apiceque fuscatis annulatisque, adjectis seepe inferioribus tenuioribus albis, superiore in areolis - 
superioribus porrecto, ceteris deflexis ; ovario clavato gracili pulvillis 25 versus apicem aggregatis griseo-villosis et 
fulvo-setosis stipato; sepalis tubi sub-13 oburvate-arbioatatle abbreviatis cuspidatis ; petalis 13 obovatis sub-emarginatis 
mucronulatis flavis basi aurantiacis ; stigmatibus 7-8 erectis virescentibus ; md minore oblonga profunde umbilicata, 
seminibus minoribus irregulariter angulatis anguste marginatis. (Tab. LXXYV. fig. 
Sand-bills on the Rio Grande near El Paso, from Doiia Ana to San Elizario aed: Flowers in May. — About 
a foot high, spreading; joints 3-6 inches long, 2-4 inches wide ; leaves 2 lines long or less, } line in diameter; pulvilli 
2 inch or in the largest specimens almost an inch apart, with short gray wool, and bright, reddish-brown, slender 
Teletlen, 1-1} line long. Spines stiff and very straight, but flexible ; lowest ones 3-1} inch long ; upper ones 13-2} or 
rarely even 3 inches long, whitish or in some species brown toward the base or on the lower half, always darkish at tip. 
Flower 23-3 inches in diameter ; ovary 1-1} inch long, slender; sepals remarkably short; petals rounded or somewhat 
emarginate, 1-1} inch long, 6-9 lines broad, yellow, with orange-red at base, turning all red on the second day 
of flowering. Fruit 1-1} inch long, with a very deep usar and without any contraction at base. Seeds [51] 
1.5~-2.0 lines in diameter, deeply notched at the hilum, very irregular. Distinguished from the nearly allied 
O. pheacantha by its thinner joints, slenderer and longer spines, Bese flowers, different fruit, etc. 
7. ©. FILIPENDULA, sp. nov.: adscendens, glauca ; radicibus nodoso-incrassatis tuberiferis ; articulis minoribus 
diversissimis orbiculatis seu siicaitd seu oblanceolatis tenuibus ; foliis minutis subulatis ; palvillis approximatis in 
tomento albo setas numerosas tenuisissimas penicillatas demum elongatas virescenti-stramineas — plurimis 
armatis seu omnibus plus minus inermibus ; aculeis 1-2 albidis elonpatis setaceis non raro subangulatis tortisque, 
1-2 minoribus sepe adjectis ; ovarii subcylindrici gracilis pulvillis 16-20 villo albo et setis parcis stramineis munitis 5 
sepalis tubi sub-8 Lsiscbitatie interioribus obovato-cuspidatis ; petalis 8 late obovatis retusis purpurascentibus margine 
pallidioribus ; ~ ie purpurascente ; stigmatibus 5 erectis flavidis ; seminibus minoribus tumidis anguste crasseque 
marginatis. (Tab. LX VIII.) 
Alluvial bottoms of the Rio Grande, in rather fertile soil, near Dofia Ana, above El Paso, and at San Elizario, 
below it; also on alluvial prairies between El Paso and the Limpia (Wright). Flowers in May and June. — The 
tubers of the root, }~-1 inch thick, are long and peorerbs or oval, or globular swellings of the roots, strung upon thick 
fibres ; these tubers will sprout when planted. The stems are 6-12 inches high and spreading ; joints of a bluish, 
hue, more so than any other of our species, very y vitisble in shape, orbicular, or even transverse to obovate 
and lasiévolate ; often on the same plant, 14-3 inches long, 1-2 inches wide, very much compressed ; leaves 13-1} line 
long ; pulvilli 4-6 lines apart, with a perfectly white tomentum, becoming gray when old, and numerous slender, 
greenish-yellow bristles, which finally hecome 2-3 lines long and very conspicuous. Sometimes the joints are entirely 
spineless, but usually they are armed with long, deflexed, very slender white spines, the longer ones 1-2 inches, the 
lower and shorter ones less than 1 inch in length ; ovary slenderer than in any other species known to me, an in 
long, at top hardly more than 3 lines wide. Flowers about 2} inches in diameter, purplish, without any mixture of 
