Mamillaria strobiliformis Scheer in Salm Cact. Hort. Dyck. 104 (1850), not Muhlenpf. (1848), nor Engelm. (1848).

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

Ovate to cylindrical, 5 to 15 cm. high, 2.5 to 5 cm. in diameter, simple or branching at base: tubercles short-ovate from a broad base, 5 to 6 mm. long, deeply grooved, crowded and imbricate, at length covering the older parts as naked and gray corky protuberances: radial spines 20 to 30, slender but stiff, white, radiant and interwoven with adjacent cl.u.s.ters, 4 to 8 mm. long (uppermost rarely 10 to 12 mm.); central spines 5 to 9, stouter, purplish above, the upper ones longer, erect, 10 to 14 mm. long (sometimes even 16 to 18 mm.), the lower one shorter (6 to 8 mm.), stout, porrect or deflexed: flowers about 2.5 cm. in diameter, pale purple: fruit oval, elongated (sometimes almost cylindric), red, about 18 mm. long: seeds subglobose, brown and pitted, very small (0.8 to 1.2 mm. long). (Ill. Cact. Mex.

Bound. t. 12. figs. 1-16) Type of Scheer's strobiliformis is unknown; but the specimens of Prince Salm-Dyck in Herb. Mo. Bot.

Gard. are marked "authentic" by Dr. Engelmann. The Wright specimens in the same Herb, represent the type of M tuberculosa Engelm.

From the mountains of extreme southwestern Texas (common west of Devil's River), southward into Chihuahua and Coahuila. Fl.

May-June.

Specimens examined: Texas (Wright 18, 19, 20, 23, 24, 29, 30,31,32, 535, of 1849 and 1852; Bigelow of 1852; Engelmann, with no number or date; Evans of 1891): Chihuahua (Pringle 250, 251 in part, and 258 of 1885): Coahuila (Palmer of 1880): also specimens from Coll. Salm. Dyck in 1857; also growing in Mo Bot. Gard. 1893 (specimens, sent by G. G. Briggs in 1892 from El Paso, Texas.

The identification of Engelmann's tuberculosa with Scheer's strobiliformis was made by Dr. Engelmann himself upon an examination of Scheer's type. The use of the specific name tuberculosa is necessitated by the law of h.o.m.onyms, as strobiliformis had been used twice already before it was taken up by Scheer. M. strobiliformis Muhlenpf. is C. scolymoides sulcatus; and M. strobiliformis Engelm. is C. conoideus.

57. Cactus viviparus Nutt. in Fraser's Cat. (1813).

Mamillaria vivipara Haw. Syn. Succ. Suppl. 72 (1819).

Low and depressed-globose, usually proliferous and cespitose (forming large ma.s.ses), but sometimes simple: tubercles terete and loose, lightly grooved: radial spines 12 to 20, stiff and white, often dark-tipped, 6 to 8 mm. long; central spines usually 4 (sometimes less, often more, even as many as 8), brownish, 8 to 12 mm. long, 3 spreading upwards, the lowest stouter and shorter and deflexed: flowers about 3.5 cm. long (large for the size of the plant) and even broader when expanded, bright purple: stigmas pointed with a short mucro: fruit oval, pale green, juicy, 12 to 18 mm. long: seeds yellowish-brown, obliquely obovate and curved about the small hilum, 1.4 to 1.6 mm. long). (Ill. Cact. Mex.

Bound. t. 74. fig. 3, seeds) Type unknown.

On the northwestern plains, from the boundary provinces of British America (western Manitoba, a.s.siniboia and Alberta), and throughout the Upper Missouri region, southward through western Nebraska to western Kansas and to the eastern foothills of central Colorado. It is also mentioned by Howell (Cat. of Oregon, Washington and Idaho plants), as occurring beyond the Rocky Mountain divide in Idaho and Washington, which is probable, but no specimens have been seen.

Specimens examined: Montana (Hayden, nos. 1854, 1855; Vernon Bailey of 1890, near Bridger): Colorado (Hayden of 1869): Nebraska (Rydberg 1379 of 1893, Thomas Co.): also specimens cultivated in St. Louis in 1869; also growing in Mo. Bot. Gard.

1893.

It seems best to keep this northwestern form specifically separate from that large a.s.semblage of southern forms that have been commonly referred to it. The forms referred to this species from western Kansas (Smyth's check list) have not been examined, and they may represent intermediate forms, inclining to simple habit and ovate form, as in the Colorado forms. The southern type (C. radiosus) is distinguished from C. viviparus not only by its very different range, but also by its ovate to cylindrical form, simple habit, more numerous (12 to 40) and longer (6 to 22 mm.) radial spines, usually more numerous (3 to 14) central spines in which the upper are more robust than the lower, porrect lower central, obtuse stigmas, and brown obovate straight seeds.

58. Cactus radiosus (Engelm.).

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.

59. Cactus radiosus neo-mexica.n.u.s (Engelm.).

Mamillaria vivipara radiosa neo-mexicana Engelm. Syn. Cact.

269 (1856).

Generally lower (3.5 to 10 cm.) and subglobose to ovate or even sub-cylindrical, branching at base or simple, with more numerous (12 to 40) radial spines, more numerous (3 to 12) and purplish centrals, and smaller seeds. (Ill. Cact. Mex. Bound. t. 74. fig.

4, seeds) Type, presumably the Wright, Bigelow, and Schott specimens from western Texas, New Mexico, and Sonora, all in Herb. Mo. Bot. Gard.

From southern Utah, central Colorado, and western Kansas, southward through western Texas, New Mexico and Arizona into Chihuahua and Sonora.

Specimens examined: Kansas (Carleton 530 of 1891, in Meade County): Oklahoma (Carleton 233 of 1891): Colorado (Hall and Harbour of 1862; Brandegee 645 of 1873; Hicks of 1890): Utah (Siler of 1870): New Mexico (Wislizenus of 1846; Fendler 244, 271, of 1847: Wright 298; Bigelow of 1853; G. R. Vasey of 1881): Texas (Wright of 1849, 1851, 1852; Bigelow of 1853): Arizona (Rothrock, with no number or date): Sonora (Schott of 1855): Chihuahua (Evans of 1891, near Juarez).

It is through this variety that C. radiosus approaches most nearly to C. viviparus, in the forms with few radials and centrals, but the specific characters seem to hold. This is the Mamillaria vivipara of the Syn Fl. Colorado (Porter and Coulter).

60. Cactus radiosus arizonicus (Engelm.).

Mamillaria arizonica Engelm Bot. Calif. i. 244 (1876).

A robust globose or ovate simple form (7.5 to 10 cm. in diameter), with long (12 to 25 mm.) deeply-grooved tubercles, 15 to 20 long (10 to 30 mm.) rigid whitish radial spines, and 3 to 6 centrals deep brown above. Type, the specimens of Cous, Palmer, Bischoff and Johnson, all in Herb. Mo. Bot. Gard.

Sandy and rocky soil from southern Utah through northern and western Arizona to southern California.

Specimens examined: Arizona (Cous of 1865; Cous & Palmer of 1865 and 1872; Palmer of 1869; Bischoff of 1871; Miller of 1881; Rusby 617 of 1853; Pringle of 1884): Utah (Johnson of 1871, 1872, 1874; Parry of 1875, 1877): California (Parish of 1880): also specimens cultivated in Mo. Bot. Gard. in 1881; and in Meehan's Gard. in 1882.

61. Cactus radiosus deserti (Engelm.).

Mamillaria deserti Engelm. Bot. Calif. ii. 449 (1880).

Subglobose or oval (5 to 10 cm. high) and simple, with deeply grooved tubercles (slender and about 12 mm. long), 25 to 30 rather long (10 to 16 mm.) grayish white radial spines (the larger with reddish tips), 3 or 4 shorter and stouter centrals with 5 or 6 intermediate ones above, small (2.5 cm. long) straw-colored flowers (becoming purplish-tipped), 5 or 6 stigmas, and obliquely obovate curved seeds. Type, Parish 433 in Herb.

Mo. Bot. Gard.

In the mountains bordering the deserts of southeastern California (San Bernardino County) and extending to central Nevada (Reese River Valley).

Specimens examined: California (Parish 453 of 1880, also of 1882; Bailey of 1890): Nevada, Lincoln County (Coville & Funston of 1891, Death Valley Expedition): also specimens cultivated in Meehan's Gard. in 1882.

The smaller straw-colored flowers alone suggest the propriety of keeping this form specifically distinct, but even in size and color there is an occasional tendency toward the specific character. The obliquely obovate curved seeds resemble those of C. viviparus. The plant densely covered with stout ashy-gray interlocking spines is easily recognized.

62. Cactus radiosus chloranthus (Engelm.).

Mamillaria chlorantha Engelm. Wheeler's Rep. 127 (1878).

Oval to cylindrical (7.5 cm. in diameter, sometimes 20 to 22.5 cm. high), with 20 to 25 gray radial spines almost in two series, 6 to 9 stouter reddish or brownish-tipped centrals (12 to 25 mm.

long), and yellowish or greenish-yellow flowers 3.5 cm. long and wide. Type: Southern Utah specimens of both Parry and Johnson occur in Herb. Mo. Bot. Gard., but they are all referred to C.

radiosus arizonicus, and I can find no trace of any specimens of C. radiosus chloranthus in the Engelmann collection.

Southern Utah, east of St. George (Parry; Johnson).

The plant is evidently near C. radiosus deserti, of which variety it seems to be the Utah representative, but in the absence not only of the type, but even of authentic specimens, the two are kept separate, a thing fully justified by the description.

63. Cactus radiosus alversoni, var. nov.