lll 
Specimens examined: MonTana (Notestein of 1893): NATIONAL 
PARK (Tweedy 423): Sourm DAKOTA, (collectorun known, in 1847, 1848, 
1853): NEBRASKA (/Zayden of 1855), 
38. Cactus missouriensis similis (Engelm.), 
Mamillaria similis Engelm. Pl. Lindh. 246 (1845). 
Mamillaria nuttallii cespitosa Engelm. Syn. Cact. 265 (1856). 
Mamillaria missouriensis cespitosa Watson, Bibl. Index, 403 (1878). 
Cespitose, with 12 to 15 puberulent radial spines, the central very 
often wanting, larger flowers (2.5 to 5 cm. long), fruit and seeds (1.6 to 
2.2 nm. indiameter), and 5 stigmas. (I//. Cact. Mex. Bound. t. 74. f. 7, 
seeds)—Type, Lindheimer, of 1845 (?) in Herb. Mo. Bot. Gard. | 
From the Kansas River, Kansas, and eastern Colorado, southward 
through Oklahoma to the San Antonio River, Texas. 
Specimens examined: COLORADO (Greene of 1870): KANSAS (Carle- 
ton 551 of 1891, from Kingman County, distributed as Mamillaria dasy- 
acuntha): 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, 1801, 
The cespitose masses are often a foot broad. 
39. Cactus missouriensis robustior (Ingelm.). 
Mamillaria similis robustior Engelm. Pl. Lindh. 200 (1850), 
Mamillaria nuttallii robustior Engelm. and Bigel. Pacif, R. Rep. iv. 28 (1856). 
Mamillaria missouriensis robustior Watson, Bill. Index, 440 (1878). 
Almost simple, with longer and looser tubercles, 10 to 12. stouter 
radial spines (6 to 16 nm. 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. 
40. Cactus scheerii (Muhlenpf.) Kuntze, Rev. Gen. P1. 261 (1891), 
Mamillaria scheeriti Muhlenpf. Allg. Gart. Zeit. xv. 97 (1847). 
Mamillaria scheerii valida Engelm. Syn. Cact. 265 (1856). 
Ovate-globose, 7.5 to 17.5 em. high, 7.5 to 12.5 cm. in diameter, sim- 
ple or sparingly proliferous at base: tubercles large (2.5 to 3.5 om. 
long), from a broad base and suddenly contracted and almost cylindric 
(10 to 14 mm, in diameter), deeply grooved (1 to 6 orbicular glands in 
the groove), distant, spreading and ascending, the lower ones shorter, 
more conical and somewhat imbricated, with broad axils and the 
younger densely woolly: radial spines 6 to 16, straight or slightly curved, 
stout, rigid, bulbous at base, whitish or yellowish (sometimes reddish) 
with dark tip, the 2 to 5 lower and lateral ones stouter and compressed 
(18 to 30 mm. long), the 4 to 11 upper ones weaker and terete (10 to 20 
mm. long); central spines 1 to 5, stout and angled, 20 to 36 mm. long, 
