13 
culis teretibus laxis leviter sulcatis; axillis subvillosis; aculeis rectis 
tenuibus setaceis patulis, exterioribus 25 - 35 albidis, interioribus 7 -13 
longioribus purpureo-fuscis, centrali infero sequilongo; baccis cen¬ 
tralibus ovatis; seminibus obovato-globosis nigricantibus scrobiculatis. 
El Paso and eastward. — Specimens before me are 1J - 2^ 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. vivipara, Haw. : simplex s. caespitosa; tuberculis teretibus 
laxis leviter sulcatis; aculeis rectis rigidis, exterioribus patentissime 
radiantibus albidis 12-36, centralibus 3-12 robustioribus longiori¬ 
bus obscurioribus, singulo robustiore porrecto defle&ove, 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, 
caespitosa; aculeis radialibus 14 - 20, centralibus 3-8. 
Var. ? $. radiosa : ovata s. subcylindrica, simplex s. e basi ramosa ; 
aculeis radialibus 12 - 36, centralibus 3 - 12. Subvar. a. radiosa 
borealis : subglobosa ; aculeis radialibus albidis 12 - 20, centralibus 
3-6 purpureo-maculatis ; floribus minoribus. — b. radiosa Neo- 
Mexicana : ovata ; aculeis radialibus albidis 20 - 36, centralibus 
3-12 supra purpurascentibus sphacelatis; floribus majoribus. — 
c. radiosa Texan a : 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 ; j3. a. in Northern New Mex¬ 
ico ; /3. b. from Western Texas to New Mexico and Sonora ; /3. 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, - 2 inches in diameter; tubercles 4-6 lines 
long; spines always rigid, 3-10 lines long. Flowers different in 
size, 1£ - 2J- inches in diameter, beautifully purple, with numerous 
narrowly lanceolate acuminate petals. Seeds J - 1 line long. 
