Specimens examined: Colorado (Greene of 1870): Kansas (Carleton
551 of 1891, from Kingman County, distributed as Mamillaria
dasyacantha): Oklahoma (Carleton 120 of 1891): Texas (Lindheimer
of 1845, 1850; Wright of 1850; Reverchon 725): also specimens
cultivated in Goebel's Garden in 1846; and in St. Louis in 1846,
1847, 1851.

The cespitose masses are often a foot broad.

39. Cactus missouriensis robustior (Engelm.).

Mamillaria similis robustior Engelm. Pl. Lindh. 200 (1850).
Mamillaria nuttallii robustior Engelm. and Bigel. Pacif. R.
Rep. iv. 28 (1856).
Mamillaria missouriensis robustior Watson, Bibl. Index,
440 (1878).

Almost simple, with longer aid looser tubercles, 10 to 12 stouter
radial spines (6 to 16 mm. long), a single stout central, larger
flowers, and 7 or 8 stigmas. Type, Lindheimer of 1845 in Herb.
Mo. Bot. Gard.

From southeastern Colorado and the Canadian River (Oklahoma and
Indian Territory), to the Colorado River of Texas.

Specimens examined: Texas (Lindheimer of 1845, 1846; Bigelow of
1853): also specimens cultivated in St. Louis in 1847.

In Bigelow's specimens the central spine is mostly lacking.