126 
ovary, and above it form a tube or cup, nectariferous at base; single 
style with several or numerous stigmas, and fruit a pulpy or rarely dry 
1-celled berry. 
I. No leaves proper: spines never barbed : flower-bearing and spine-bearing areolw 
distinct : tube of the sessile solitary flowers well developed, often long. 
1. Mamillaria. Globose or oval plants, covered with spine-bearing tubercles, 
(except in one group): flowers (usually small) from between the tubercles: ovary 
naked. 
9. Echinocactus. Globose or oval plants, stouter than the last, usually ribbed» 
with bundles of spines on the ribs: flowers mostly larger, from the youngest part of 
the ribs close above the nascent bunches of spines ; ovary covered with sepals. 
8 Cereus. Oval or columnar plants, sometimes tall, ribbed or angled, with ‘un- 
dles of spines on the ribs: flowers usually larger, close above the bundles of full 
grown (older) spines: ovary covered with sepals. 
II. Leaves small, subulate, early deciduous: sessile and solitary flowers from the same 
areolie as the always barbed spines: tube of the flowers short, cup-shaped, 
4, Opuntia. Branching or jointed plants: joints flattened or cylindrical. 
1. MAMILLARIA Haworth. 
Small, more or less globose or oval simple or cespitose plants, the 
spine-bearing areole borne on cylindric, oval, conical, or angular tuber- 
cles which cover the body of the plant, with flowers about as long as 
wide, the tube campanulate or funnel-shaped, from a distinct woolly 
or bristly areola at the base of the tubercles, fully open in sunlight 
and only for a few hours, and ovary often hidden between the bases of 
the tuberzles and naked, as is also the exsert succulent berry.—In one 
group the tubercles are unarmed. 
* Flowers lateral from the axils of older or full-grown tubercles which are never grooved : 
ovary generally immersed but becoming exserted lowards maturity. 
+ No centrul spines. 
1. M. micromeris Eng. Simple and globose, 12 to 36 mm. in diameter: tubercles 
very small, 1 to 2 mm. long, crowded: younger areolw only clothed with loose wool: 
spines slender, ash-gray, in many series, 1 to 3 mm. long, in younger plants about 
290 end equal, in flower-bearing tubercles 30 to 40, all stellate-spreading, the uppermost 
(G6 to 8) 2 to 4 times as long as the others and strongly clavate; flowers nearly central, 
6 mm. in diameter, light pink.—From the San Pedro to El Paso. 
9. M. lasiacantha Eng. Simple and globose, 12 to 36 mm. in height and scarcely 
less in diameter: tubercles terete, 4 to 6mm, long: spines slender, from densely pilose 
to almost naked, in many series, 40 to 80, all radiating, 3 to 5 mm. long: flowers lat- 
eral, 12 mm. long, whitish or very pale pink.—On the Pecos and westward. 
+ + Central spines mostly longer and hooked. 
3. M. pusilla DC., var, TEXANA Eng. Ovate-globose, proliferous, cespitose, 2.5 
to 6.5 em. high: tubercles terete, 7 to 9 mm. long, long- woolly in the axils : spines in 
many series, the outermost 30 to 50 hairlike and crisped or twisted, the interior 10 to 
12 more rigid, shorter and white, the innermost 5 to 5 central ones straight, rigid and 
longer, dusky towards the apex: flowers lateral, 14 to 20 mm. long, reddish.—On the 
Rio Grande near Eagle Pass and southward. 
4, M. Grahami Eng. Subglobose, simple or at length branched from the base, 2.5 
to 7.5 em. high: tubercles ovate, 6 mm. long with naked axils: radial spines 20 to 
>) 
30 in one series, 6 to 12 mm. long, thin and whitish, a single central much longer and 
