Mamillaria vivipara Engelm. Pl. Fendl. 49 (1849), not Haw.
(1819).
Mamillaria radiosa Engelm. Pl. Lindh. 196 (1850).
Mamillaria vivipara radiosa texana Engelm. Syn. Cact. 269
(1856).
Ovate or cylindrical, 5 to 12.5 cm. high and about 5 cm. in
diameter, simple or sparingly proliferous: tubercles terete, more
or less grooved above, 8 to 12 mm. long: radial spines 20 to 30,
straight, slender, with with dusky apex, very unequal, 6 to 8 mm
long; central spines 4 or 5, stouter, yellowish or tawny, 8 to 12
mm. long, the upper ones the longer and more robust, the lowest
one shorter and porrect: flowers 3.5 to 5.5 cm. long, about the
same diameter when fully open, violet to dark purple: stigmas 7
to 9, obtuse: fruit oval and green: seeds yellowish or brown,
obovate, pitted, fully 2 mm, long. (Ill. Cact. Mex. Bound. t.
74, fig.5, seeds) Type, Lindheimer of 1846 in Herb. Mo. Bot.
Gard.
Extending across southern Texas, from the Guadalupe to El Paso.
thence into contiguous New Mexico and across the Rio Grande near
Juarez (northern Chihuahua). Fl. May-June.
Specimens examined: Texas (Lindheimer of 1846): New Mexico
(Bigelow of 1855): Chihuahua, near Juarez (Evans of 1891): also
specimens cultivated from the type in St. Louis in 1846.
Attention has been called under C. viviparus to the characters
that distinguish from C. radiosus The characters there given for
the latter species apply to to the whole group of included forms.
The type of the species is the var. Texana of Engelmann's Syn.
Cact. and Mex. Bound., which is characterized in the above.
description.