10. Cactus lasiacanthus (Engelm.) Kuntze, Rev. Gen. Pl. 259
(1891).

Mamillaria lasiacantha Engelm. Syn. Cact. 261 (1856).

Globose or ovate globose, 2 to 2.5 cm. high and 1 to 2 cm. broad:
tubercles 4 mm. long, about 2 mm. in diameter, with naked axils:
spines 40 to 60, in many series, very unequal, 2 to 4 mm, long,
white and pilose, the upper exterior usually longer than the
rest, the innermost usually much shorter: flowers 12 mm. long,
whitish or pinkish (petals with red median band): fruit 1 to 2
cm. long: seeds about 1 mm. long, blackish and conspicuously
pitted. (Ill. Cact. Mex. Bound. t. 3). Type, the specimens of
Wright in Herb. Mo. Bot. Gard.

From western Texas ("west of time Pecos, on low limestone hills,
among herbage") to Arizona and Chihuahua. Fl. April, May.

Specimens examined: Texas (Wright 121, also of 1852; Parry of
1852): Arizona (Miller of 1881): Chihuahua (Pringle 213,
250,258): also specimens cultivated in St. Louis in 1852 and
1855.

11. Cactus lasiacanthus denudatus (Engelm.).

Mamillaria lasiacantha denudata Engelm. Cact. Mex. Bound. 5
(1859).

Larger, 2.5 to 3.5 cm. in diameter, with longer tubercles (5 to 6
mm.), and more numerous (50 to 80) longer (3 to 5 mum.) spines