porrect central spine is found. These intergrading forms I have
only seen in Mexican material. For discussion of relationships
see under C. scolymoides.

** Flowers red.
+ Central spine solitary or sometimes wanting.

51. Cactus dasyacanthus (Engelm.) Kuntze, Rev. Gen. Pl. 259
(1891).

Mamillaria dasyacantha Engelm. Syn. Cact. 268 (1856).

Subglobose, 3.5 to 6.5 cm. high, simple: tubercles slender and
terete, spreading, lightly grooved even to the base, 8 to 10 mm,
long: radial spines 30 to 50, mostly in two series, straight and
loosely spreading, the exterior ones (25 to 35) capillary and
white, 6 to 18 mm. long, the interior ones (7 to 13) stiffer
(setaceous), longer and darker and black-tipped; the central
spine straight and porrect, 12 to 20 mm. long, often wanting:
flowers small, red: fruit ovate, small (8 to 10 mm. long?): seeds
globose-angled, almost black, pitted, 0.8 to 1.2 mm. long (Ill.
Cact. Mex. Bound. t. 12. figs. 17-22) Type, Wright 110 in Herb.
Mo. Bot Gard.

From Eagle Pass, Texas, westward to El Paso and southern New
Mexico, and southward into Chihuahua.

Specimens examined: Texas (Wright 110 of 1852): New Mexico (Vasey
of 1881; Mearns of 1892, in Big Hatchet Mountains) Chihuahua
(Pringle 251 of 1885, in part).