Globose or subconical, 3.5 to 6.5 cm. in diameter, simple: tubercles terete, conical, grooved above, 10 to 12 mm. long: radial spines 16 to 30, pectinate, straight or little curved, rigid and appressed (interwoven with neighboring clusters), ashy-white (often dusky at apex), 8 to 12 mm. long, the uppermost longer (12 to 20 mm.); central spines 3 or 4, the upper ones turned upward and intermixed with the radials, the lower one very stout, 15 mm. long, subulate from a very thick bulbous base, straight (rarely slightly curved) and porrect (deciduous in old specimens): flowers 3 to 5 cm. long: fruit oval, elongated, about 2 cm. long, green: seeds elongated- obovate. brown and smooth, about 1.8 mm. long. (Ill. Cact. Mex. Bound. t. 10)Type, the Wright and Bigelow specimens in Herb. Mo. Bot. Gard.
On limestone hills, from the Pecos River, southwestern Texas, and southern New Mexico, westward to the Rio Grande (from Presidio del Norte northward).Fl. June.
Specimens examined: Texas (Wright of 1849, 1851, 1852; Bigelow of 1852; Engelmann, with no number or date; Evans of 1891).
The characteristic appearance of the plant is given by the very stout and straight central spine standing in each cluster perpendicular to the plant body.The range of this species, between the Pecos and the upper Rio Grande, suggests another separated group, such as is presented by C. scolymoides sulcatus to the east, between the Brazos and Nueces.Very frequently specimens of C. echinus occur in which some of the tubercles do not develop central spines, and then the spine characters resemble thoseof C. radians.In C. radians, also, an occasional 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 dasyacanthaEngelm. 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).
Pringle 251 as distributed to Nat. Herb. is C. tuberculosus.
52.Cactus maculatus, sp. nov.
Obovate-cylindrical, 6 by 8 cm., somewhat cespitose: tubercles ovate, terete, 10 mm. long, grooved to the base, with naked axils: radial spines 10 or 11, straight and spreading, rigid, blackish (becoming ashy with age), black-tipped, 12 mm. long; central spine large, more or less spotted, erect, 25 to 35 mm. long: flower 13 mm. long, pinkish: fruit unknown.Type in Herb. Coulter.
San Luis Potosi.
Specimens examined: San Luis Potosi (Eschanzier of 1891).
Somewhat resembles C. tuberculosus in general appearance, but very different in spine characters.
53.Cactus brunneus, sp. nov.
Obovate-cylindrical, 3 by 6 cm., simple: tubercles ovate, grooved to the base, 5 to 6 mm. long, with woolly axils: radial spines 11 to 15, spreading, rather rigid and brownish (lighter with age), 8 to 10 mm. long; central spine much larger, 20 mm, long, hooked: flower and fruit unknown.Type in Herb. Coulter.
San Luis Potosi.
Specimens examined: San Luis Potosi (Eschanzier of 1891).
Central spines 3 to 12.
54.Cactus conoideus(DC.) Kuntze, Rev. Gen. Pl. 260 (1891).
Mamillaria conoideaDC. Rev. Cact. 112 (1829). Mamillaria strobiliformisEngelm. Wisliz. Rep. 113 (1848), not Scheer (1850).
Ovate-conical, 3.5 to 10 cm. high, 4 to 7 cm. in diameter below, with densely woolly vertex, simple: tubercles conical, about 12 mm, long, closely appressed-imbricate ("giving the plant the appearance of a pineapple or cone"): radial spines 10 to 16, ashy to white, straight and stout, 6 to 10 mm. long, the upper longer (10 to 15 mm.); central spines 3 to 5, stouter, brownish-black, 10 to 16 mm. long, the two or three smaller ones erect-spreading, the single lower one more rigid, porrect or deflexed, 15 to 20 mm. long: flowers 2 to 3 cm long and wide, deep purple: fruit unknown.(Ill. DC. Mem. Cact. t. 2)Type unknown.
On rocks, Coahuila and Nuevo Leon to San Luis Potosi and southern Mexico.
Specimens examined: Coahuila (Palmer 378 of 1882; Pringle 3117 of 1890): Nuevo Leon (Wislizenus of 1847): San Luis Potosi (Poselger of 1851; Eschanzier of 1891).
55.Cactus potsii(Scheer) Kuntze, Rev. Gen. Pl. 261 (1891).
Mamillaria potsiiScheer in Salm Cact. Hort. Dyck. 104 (1850).
Cylindrical, 30 to 35 cm. high, 2.5 to 3 cm. in diameter, somewhat branching: tubercles ovate, obtuse, very lightly sulcate, with somewhat woolly axils: radial spines very numerous (entirely covering the whole plant), slender and white; central spines 6 to 12, stouter from a broad base: flowers large, green, or reddish: fruit red.Type unknown.
From the Rio Grande region, near Laredo, Texas, to Chihuahua. Specimensexamined:Texas(Poselgerof1851):Chihuahua(specimens from Coll. Salm-Dyck.).
56.Cactus tuberculosus(Engelm.) Kuntze, Rev. Gen. Pl. 261(1891).
Mamillaria strobiliformisScheer in Salm Cact. Hort. Dyck. 104 (1850), not Muhlenpf. (1848), nor Engelm. (1848). Mamillaria tuberculosaEngelm. Syn. Cact. 268 (1856).
