9 
Var..8. czsritosa (M. similis, E. in Pl. Lindh. 1845) ; cespitosa ; 
aculeis radialibus 12-15 puberulis, centrali plerumque déficiente ; 
floribus:baccis seminibusque majoribus ; stigmatibus 5 patulis. © 
Var. y. RopusTior, E. in PI. Lindh. 1850: subsimplex ; tuberculis 
longioribus laxioribus, aculeis robustioribus levibus, radialibus 10— Rm 
centrali singulo ; floribus majoribus ; stigmatibus 7-8 patulis ; semini- 
bus ut in 8. 
Plains east of the Rocky and New Mexican Mountains. ‘Var. a. on 
the Upper Missouri; 8. from Kansas River to New Braunfels in Texas ; 
y: from the Canadian River to the Colorado of Texas. The. heads 
are one or two inches in diameter; the caspitose masses of 8. often a 
foot broad ; spines 3-8 lines long. Flowers 1-2 inches long and 
wide, of a greenish or reddish or pure pale yellow color. Seeds 
0.8 — 1.1 lines in diameter, more regularly ates than in most other 
Cactacze. 
16. M. Scueeri, Muhlenpf. 1847; 8. ? vauipa, E. in B.C. R.: 
magna, ovato-globosa, subsimplex, glaucescens; tuberculis remotis™; 4... 
patulis magnis e basi Jata subcylindricis supra sulco profundo glandu- -» ; 
lis paucis munito (juniore lanato) subbilobis ; areolis junioribus dense 
lanatis ; aculeis 10 — 20 rectis robustis basi bulbosis albidis s. citrinis 
apice fuscatis, radialibus 9-—1€ ‘entralibus 1-5 validioribus angu- 
latis ; floribus flavis ex axillis junioribus tomentosissimis. 
Sandy ridges in the valley of the Rio Grande near El Paso: fl. 
July. The largest of our Northern Mamillarie, '7 inches high and 5 
in diameter; tubercles 1-134 inches long; spines 10-18 lines in 
length, very stout, especially the central and lower radial ones. 
Flower 2 inches long, yellow. Fruit not seen.— M. Scheerii from 
Chihuahua, according to Prince Salm’s description, is a smaller plant, 
with single central spines one inch in length, and 8- 11 much shorter 
radial spines ; the areolz are described as naked : — nevertheless our 
plant is probably only thé northern form of this species. 
17. M2 rosustisrina, A. Schott, in litt: simplex s. cespitosa ; 
tuberculis patulis teretibus magnis sulcatis ; areolis junioribus dense 
tomentosis ; aculeis radialibus 12-15 robustis inferioribus robustiori- 
bus sepe curvatis, superioribus rectis fasciculatis paullo tenuioribus, 
centrali singulo valido compresso recurvato, omnibus subpollicaribus 
corneis apice atratis ; floribus luteis ex axillis junioribus tomentosis- 
simis ; seminibus magnis obovatis fuscis lzevibus. 
Sonora, on grassy prairies: fl. July. Tubercles nearty an inch 
2 
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