uf Mammillaria—continuwed. 
; M. Nickelsz (Nickelsi’s). 7. having a red tube, 2in. or more 
across. Stems ciespitose from the upper part of the groove; 
tubercles }in. long, ovate-oblong; radial spines fourteen to 
eighteen, the upper ones fascicled and much longer than the 
lower ones. Mexico. This probably is the same plant offered 
by dealers as M. Nicholsoni. Syn. M. Nickelsii, of gardens. 
Fic. 552. MAMMILLARIA MACROMERIS. 
M. Nickelsii. A synonym of M. Nickelse. 
M. nivea (snowy). A form of M. bicolor. 
M. Nuttallii (Nuttall’s). A synonym of M. missouriensis. 
M. Ottonis (Otto’s).* /. white, large for the size of the plant. 
May and June. Stem small, compressed, 3in. across, with 
= numerous compressed tubercles, and short, hair-like spines, 
Mexico, 1834. See Fig. 553. ‘there is another species called 
M. Ottonis, having a large, spiny stem. 
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Fic. 553. MAMMILLARIA OTTONIS. 
M. Peacocki. The correct name is M. dealbata. 
M. Pfeifferi (Pfeiffer’s).* Stems having the spines subulate, 
fawn-coloured at first, but afterwards bright golden. This 
plant closely resembles M. rhodantha; in fact, it is now 
classed as a variety of that species. A beautiful Cactus. 
M. phellosperma (corky-seeded). Stems simple, sometimes 
proliferous at the base, globose when young, afterwards almost 
cylindrical or pear-shaped, Sin. high, 2in. in diameter ; tubercles 
4in. long, arranged in twelve spiral rows, slightly woolly in the 
axils ; spines radiating in two rows, about fifty on each tubercle, 
the three or four central ones hooked at the tip or sometimes 
straight, and almost black, while the remainder are almost 
white. This plant has not been known to flower under 
cultivation. 
M. Potosina (Potosin’s). A garden synonym of M. elegans. 
M. Purpusi (Purpus’s). 7. red, small, disposed in a circle near 
the apex. Stem simple, rarely proliferous, cylindrical or cone- 
shaped, 4in. high; tubercles in twelve to twenty rows, each 
1900 SUPPLEMENT—RECENT INTRODUCTIONS, 
&C. 517 
Mammillaria—continued. 
bearing a tuft of about twenty white radial spines, and six red 
central straight ones. Mountains of Colorado, 1894. Said to be 
one of the hardiest of Cacti. 
rN E 
Fig. 554. MAMMILLARIA RADIOSA. 
fl. violet. May and June. This is 
distinguished from M. vivipara by its ovate to cylindrical 
form, simple habit, more numerous (twelve to twenty) and 
longer radial spines, usually more numerous (three to fourteen) 
central spines of which the upper are more robust than the 
lower, and obtuse stigmas. Southern Texas, &e. See Fig. 554. 
Syn. M. vivipara radiosa. 
M. r. Alversoni (A. H. Alverson’s).*  Fox-tail Cactus. This 
differs from deserti in its more robust and branching habit 
(h. 6in.), shorter and thicker tubercles, more numerous, stouter 
and longer black-tipped spines, and pink flowers. South- 
eastern California. 
M. xr. arizonica (Arizona).* jl. rose-coloured, 2in. to 2sin. 
across. Stem globose or ovate, din. to 4in. in diameter; 
tubercles about lin. long, cylindrical, ascending, deeply grooved, 
with numerous straight, rigid spines, the fifteen to twenty 
outer ones whitish, the three to six inner ones deep brown 
and stouter. Northern Arizona. 
M. r. chlorantha (yellow-flowered). 
yellow, l}in. to 2in. long and broad. Stem ovate to 
cylindrical, sometimes 8in. to Qin. high, with twenty to 
twenty-five grey radial spines almost in two series, and six to 
nine stouter reddish or brown-tipped centrals, Southern Utah, 
1883. 
M. r. deserti (desert-loving). #. straw-coloured, becoming 
purplish-tipped, smaller than in M. r. arizonica. Stem sub- 
elobose or ovate, simple, with deeply-grooved tubercles, 
densely covered with stout, grey, interlocking spines. 
California, &c. 
M. r. neo-mexicana (New Mexican). Stem generally shorter 
than in the type, sub-globose to sub-cylindrical, branching at 
base or simple, with more numerous radial spines, and more 
numerous blackish-purple central ones. Southern Utah, &e. 
M. rhodantha (rose-flowered). The correct name of M. atrata. 
Syn. M. fulvispina. 
M. robustispina (stout-spined). 1. saffron-yellow, 14in. to 2in. 
long, with a very slender tube. July. . green. Stems large 
and stout, simple or tufted; tubercles sub-terete, lin. long; 
radial spines twelve to fifteen, stout and rigid, Zin. to lin. 
long, the lower ones stouter, more dusky, straight or eurved 
downwards, the upper ones straight and fascicled, the 
central one stout, curved downwards, all horny and black- 
tipped. Sonora. Syn. M. Brownii. 
M. Rungei (Runge’s). A synonym of M. lasiacantha. 
M. Scheerii (Scheer’s). 1. terminal, erect, with several whorls 
of spreading, recurved petals, the lower ones tinged crimson, 
the upper ones pale yellow, forming shallow cup 2in. across. 
Stem 7in. high and 5in. in diamet ut base ; tubercles large, 
swollen, somewhat flattened, the apices crowned with about 
a dozen brown spines. Mexico. 
M. radiosa (radiate). 7. 
jl. yellowish or greenish- 
