244 
CACTACEHC. Mamillaria. 
Common on sandy or gravelly soil or among rocks about San Diego {Parry, Agassiz, Hitchcock), 
and on the neighboring islands, and southward through the Peninsula, W . Gabb. From 2 or 3 
to 6 or 7 inches high, 1 to 1J thick ; tubercles -2£ to 3 lines long ; radial spines 2£ to 5, and cen¬ 
tral ones 5 to 7 lines long ; flowers 9 to 12 lines in diameter, dirty yellowish tinged with red. 
2. M. Grahami, Engelm. Similar to the last: smaller, with smaller less closely 
pitted seeds, but longer and more numerous (15 to 30) spines, and without axillary 
bristles. — Cact. Mex. Bound. 7, t. 6, fig- 1 — 8. 
Common on the most rugged rocks on both sides of the Colorado {Schott, Newberry ), and east¬ 
ward into New Mexico. Heads 1 to 3 inches high, 1 to 1J thick. 
3. M. phellosperma, Engelm. Ovate to cylindrical, usually simple : tubercles 
long-oval, with wool and bristles in their axils, and 30 to 60 spines at the apex, in 
2 or 3 series; the outer thinner and paler; the inner stouter and often darker; the 
3 or 4 central spines stouter, dark brown, and one or several hooked : flowers with 
ciliate sepals and 12 to 13 acuminate petals : stigmas 5 : berry obovate or clavate, 
crimson, containing rather few large globose .reticulated and warty brown seeds, with 
a large spongy appendage.—-Cact. Mex. Bound. 6, t. 7. 
From the eastern slope of the mountains near San Felipe to the Mohave country, and through¬ 
out Western Arizona. Heads 2 to 5 inches high, 1| to 2 inches thick ; tubercles 4 to 7 lines long, 
hot as much crowded as in the last two species, but with a much larger number of spines, 4 to 9 
lines in length ; flower dirty yellowish red, about an inch wide. The seed is partially imbedded ill 
a curious spongy mass, an aril-like enlargement of the funiculus. 
§ 2. Flowers larger, vertical , from the base of a groove on the young or nascent 
tubercles. — Coryphantha, 
4. M. Arizonica, Engelm. n. sp. Globose or ovate; tubereles long-cylindrical, 
ascending, deeply grooved, bearing numerous straight rigid spines: the 15 to 20 
exterior spines whitish; the 3 to 6 interior ones stouter, deep brown above : flowers 
'large, rose-colored: sepals 30 to 40, linear-subulate, fimbriate: petals 40 to 50, 
lance-linear, awned: stigmas 8 to 10, white : berry oval, green, with obovate com¬ 
pressed pitted light brown seeds. 
On sandy and rocky soil in Northern Arizona, from the Colorado eastward {Coues, Palmer, F. 
Bischoff), and into Southern Utah {J. E. Johnson) ; probably in Southeastern California. Larger 
in all its parts than the foregoing species ; 3 or 4 inches thick ; tubercles an inch long ; spines 5 
to 15 lines long ; flowers 2 to 2 j inches wide, very showy. 
2. ECHINOCACTUS, Link &’ Otto. 
Elowers about as long as wide. Ovary covered with sepaloid scales, naked or 
woolly in their axils. Fruit succulent or sometimes dry, covered with the persistent 
calyx-scales, sometimes enveloped in copious wool, and usually crowned with the 
persistent remnants of the flower. Seed obliquely obovate, black. Embryo curved 
over the small albumen ; cotyledons parallel to the sides of the seed. — Mostly 
larger, sometimes gigantic, globose or depressed, or ovate, or rarely subcylindric, 
simple or very rarely cespitose; bunches of spines on the more or less vertical ribs. 
Elowers contiguous to and above the spines, on the latest growth of the plant, often 
from the nascent woolly areolse and therefore more or less vertical, open only in 
sunlight. 
* Scales of the ovary ovate , orbicular , or cordate , and mostly fringedf their axils 
almost naked: fruit scaly, never woolly. — Leiocarpi. 
+- Spines smooth. 
1. E. Whipplei, Engelm. & Big. Heads solitary, globose or ovate, middle-sized, 
with 13 (to 15) compressed and interrupted ribs: of the 7 to 11 outer and 4 inner 
spines, the ivory-white upper ones are the longest and broadest and recurved or 
