13 
culis teretibus laxis leviter sulcatis ; axillis subvillosis ; aculeis rectis 
tenuibus setaceis patulis, exterioribus 25 — 35 albidis, interioribus 7 — 18 
longioribus purpureo-fuscis, centrali infero equilongo; baccis cen- 
tralibus ovatis ; seminibus obovato-globosis nigricantibus scrobiculatis. 
£1 Paso and eastward. — Specimens before me are 14 —24 inches 
high, and a little less in diameter; tubercles 4—5 lines long; spines 
more slender and soft than in the allied species, often capillary, 
spreading, but not radiating, 6 — 12 lines long, only the lower exterior 
ones a little shorter. Seeds about half a line long. Very nearly 
allied to the next. 
28. M. vivirara, Haw.: simplex s. cespitosa; tuberculis teretibus 
laxis leviter sulcatis; aculeis rectis rigidis, exterioribus patentissime 
radiantibus albidis 12-36, centralibus 3—12 robustioribus longiori- 
bus obscurioribus, singulo robustiore porrecto deflexove, ceteris sur- 
sum divergentibus ; floribus subcentralibus purpureis magnis ; baccis 
sublateralibus ovatis viridibus ; seminibus obovatis scrobiculatis fulvis. 
Var. a. vERA: depresso-globosa, simplex s. plerumque prolifera, 
cespitosa ; aculeis radialibus 14 — 20, centralibus 3-8 
Var. ? 8. RADIOSA: ovata s. subcylindrica, simplex s. e basi ramosa ; 
aculeis radialibus 12—36, centralibus 3-12. Subvar. a. rapiosa 
BOREALIS: subglobosa ; aculeis radialibus albidis 12-20, centralibus 
3-6 purpureo-maculatis ; floribus minoribus. — 6. rapiosa Neo- 
Mexicana: ovata; aculeis radialibus albidis 20 - 36, centralibus 
3-12 supra purpurascentibus sphacelatis; floribus majoribus. — 
c. RADIOSA TEXANA: ovato-cylindrica; aculeis radialibus albidis 20—- 
30, centralibus 4-5 flavis s. fulvis; floribus seminibusque magnis. 
M. radiosa, E. in Plant. Lindh. 2. 1850. 
In the Western plains, and on the Rocky Mountains: var. a. on the 
Upper Missouri and Yellowstone Rivers; 8. a. in Northern New Mex- 
ico; 8. b. from Western Texas to New Mexico and Sonora; £. c. in 
Texas, west of New Braunfels. — The extreme forms are certainly 
very unlike one another, but the transitions are so gradual that I cannot 
draw strict limits between them. Even the proliferous growth of the 
original M. vivipara is not constant, and I have seen many simple 
specimens from the Upper Missouri. The simple ones seem to flower 
better than the proliferous ones, which are often sterile. — Plants from 
1 to 5 inches high, 14-2 inches in diameter; tubercles 4-6 lines 
long ; spines always rigid, 3-10 lines long. Flowers different in 
size, 14-23 inches in diameter, beautifully purple, with numerous 
narrowly lanceolate acuminate petals. Seeds 4-1 line long. 
