82 UNITED STATES AND MEXICAN BOUNDARY. 
superioribus 3-6 setaceis brevibus fasciculatis; floribus sub vertice lateralibus ; ovarii pulvil- 
lis 50-60 aculeolos 8-12 rigidos gerentibus; sepalis tubi 40 inferioribus subulatis ad axillam 
aculeiferis, superioribus 20 lanceolatis acumiuatis; petalis sub-20 spathulatis acutiusculis 
incisota-dentatis purpureis; stigmatibus sub-12; bacca ovato-globosa aculeolata; seminibus 
tuberculatis. 
In the Sierras of Pimeria Alta in Sonora, and farther west, A. Schott: fl. June and J uly.— 
Stems 4-8 inches high, 2 inches in diameter ; areole 2-2} lines long in the larger full-grown 
specimens, 3 or 4 within one inch of the rib; in a small specimen, with only 15 ribs, smaller 
areola and smaller and more numerous spines (30-35, only 1-1} line long); 12 or more 
bunches of spines are crowded within the same space. Spines all radiating and interlocking, 
extremely rigid and acute, variegated, the latest ones of each season being rose-colored, and 
the earliest ones a pale yellowish, thus forming variegated rings around the stem. Lateral 
spines 3-43 lines long, lower one 2 lines long, upper ones still shorter. Flowers near the de- 
pressed vertex, just on the outer edge of the rounded top, 24-3 inches long, bright pink, or 
purple. Fruit subglobose, nearly an inch long, pulpy and edible ; the fleshy part of the stem is 
also eaten by the inhabitants, who call this plant “ Cabeza del Viejo.’’ Seed (not quite ripe) 6 
lines long, strongly tuberculated, closely resembling that of C. cespitosus. I can distinguish 
this plant from C. pectinatus only by the greater rigidity and thickness of the radial, and the 
entire absence of the central spines. The forms allied to (7. pectinatus are very difficult to dis- 
tinguish, and it is quite probable that they may run into one another, as Dr. Poselger, who has 
seen thousands of them in Texas and Northern Mexico, is inclined to think. I find that C. ppec- 
timatus ‘has always a distinct single inferior spine, which is only a little shorter than the lower 
lateral spines; while C. ceespitosus has generally several of the lowest spines much shorter and 
weaker than the lateral ones. C. adustus, the flower of which is not yet known, has fewer ribs, 
oval areole, and the lowest spine much as in (. pectinatus. 
6. C. cxsprrosus, E. in Pl. Lindh., which extends from the Arkansas river to Saltillo, has 
been found by Mr. Wright as far west as the Nueces and the San Pedro. The loose darkish 
wool and slender bristles on the extremely numerous (80-100) pulvilli of the flower-tube, and 
especially the position of these pulvilli,—not in the axil, but considerably above it on the sepal, 
just below its foliaceous tip,—distinguish this species from the nearly allied (. pectinatus, as well 
as from all other Echinoceret known to me. This structure of the sepals seems to imitate and 
explain the morphology of the tubercles in Mamillaria, demonstrating them not to be a branch 
or an axis, but the fleshy petiole of an abortive or depauperate leaf, which sometimes 
by an indistinct scale above the fasciculus of spines, or by the point of the tubercle of an Anhalo- 
nium. This species has 12-18 ribs, 20-30 radial spines, rarely with 1 or 2 central ones here and 
there ; flower 2-3 inches in diameter ; petals sometimes, though rarely, curly, as in our figure, 
_ mostly plain; stigmata 12-18; fruit 9-10 lines long, oval, generally bursting irregularly ; 
seed 0.6-0.7 line long, obovate, oblique, sometimes almost globose, very strongly tuberculated, 
with an oval hilum. The name C. cespitosus, which would apply much better to a number of 
other species of this section, was given before any of these were known ; it not inaptly repre- 
sents a common state of the plant when it makes 5-12 heads, but not rarely it is almost or 
quite simple. (Tab. XXXUI—XXXIV.) 
is indicated 
Tee LONGISETUS, (sp. nov.): subsimplex, ovato-cylindricus ; costis 
: 11-14 interruptis tuber- 
culatis ; areolis orbiculatis ; aculeis setaceis flexilibus albis patulis 
radialibus 18-20 rectis basi 
