UNITED STATES AND MEXICAN BOUNDARY. 
lanceolatis seu spathulatis acutis seu cuspidatis; petalis 16-24 oblongo-linearibus seu obovato- 
spathulatis acutis seu obtusis mucronatis seepe eroso-denticulatis; stigmatibus 12-16 stamina 
numerosissima vix superantibus erectis; bacca ovato-globosa ex viridi purpurascente pulvillis 
aculeolatis 18-20 stipata; seminibus oblique obovatis curvatis paullo compressis scrobiculatis 
(tuberculis irregulariter confluentibus,) hilo ovato seu subcirculari basilari; embryone paullo 
— curvato. 
In various situations, among rocks or in alluvial river-bottoms from Santa Fé, Fendler; to 
the cation of the Rio Grande below El Paso, Wright, Bigelow; and from the country fifty miles 
east of the Upper Pecos westward to Zufli and the Aztec mountains, Bigelow, and to the Copper 
mines, Thurber: fl. May and June.—Stems single or few together, 3-8 inches high, 2-3 
inches in diameter, not many together, and those usually of unequal height, not level-topped, 
like C. pheniceus and others; areole 4-7 lines apart ; spines very variable, but always charac- 
terized by their bulbous base, by the lower ones being stouter and longer than the upper ones, 
partly white and dark, and by the long and dark central spine, which is always curved upwards. 
Radial spines mostly 7, a white and angular one below, 6-12 lines long; the two next ones 
hardly longer, more terete, black on the upper and usually white on the lower surface; then 
comes a pair of white or rarely variegated spines, scarcely shorter, above them two weaker, 
whiter, and shorter spines, 3-6 or 7 lines long. This is the usual form, especially in the 
north ; often, however, two more upper spines are found, and sometimes a slender, or oftener a 
stout and dark-colored spine, not rarely 12-15 lines long, is placed on the upper edge of the 
areola, similar to, but always smaller than, the central spine, All these forms are occasionally 
seen on the same specimen. In some southern specimens I observe now and then a few small 
additional upper spines. The form which I have described in Pl. Fendleriane as 8. pauperculus , 
and which Dr. Bigelow collected also on the Pecos, has mostly only six spines: five lower and 
lateral radial ones and the central one, which, more or less, assumes the place of the absent 
upper radial spine. This, however, is not a constant form, as transitions to the usual arrange- 
ment of spines are often seen on the same specimen. Central spine very much thickened at 
base, almost terete, black, often with a lighter tip, curved upwards, 1-2 inches long. Flower 
23-33 inches long and wide, not fully open before noon, closing again after 2 o’clock ; Spines 
on the ovary 24-4, on the upper part of the tube 4-8 lines long, distinctly bulbous at base, and 
often angular ; petals 4—7 lines wide, acute or obtusish; stamina about 1600 in a specimen exam- 
ined by Mr. Wright, only from the upper and wider part of the tube, the lower and narrow part 
3-4 lines long, naked. Fruit 1-1} inches long, purplish-green, edible; seeds 0.7 line long, very 
oblique, irregularly pitted by the tubercles, as it were, running together in twisted lines. 
10. C. EynEAcantTHus, E. in Wisl. Rep.: ovato-cylindricus, obtusus, lete viridis, simplex seu 
plerumque dense cespitosus; costis 7-10 obtusis infra dilatatis sursum compressis tuberculatis 
sulco transverso seepe interruptis, sinubus profundis acutis ; areolis orbiculatis remotis ; aculeis 
rectis, radialibus 7-12 (plerumque 8) albis subpellucidis, inferioribus longioribus, centrali sin- 
gulo (raro 2 superioribus tenuioribus additis) basi bulboso teretiusculo seu plerumque plus minus 
compresso triangulatoque albido stramineo seu obscuriore radialibus longiore ; floribus sub- 
terminalibus seu lateralibus ; ovarii pulvillis 25-35 in squame triangularis axillis villosis acu- 
leolos 6-12 albidos seu fuscatos gerentibus; sepalis tubi inferioribus 18-20 cum aculeolis 
longioribus paucioribus, superioribus 10-18 oblanceolatis acutis > petalis 12-15 oblongo- 
obovatis erosis obtusis acutisve; stigmatibus 8-10 viridibus elongatis erectiusculis; bacca 
