Part 4 (1/2)

The tubercles are so close together that the plant appears thickly covered with the unusually stout and erect-spreading straight spines, a few of the centrals being specially prominent.

The plant is more slender than the ordinary ”cylindrical”

members of the genus, but stouter than the slender hooked forms of the preceding section.

26. Cactus rhodanthus (Link & Otto) Kuntze, Rev. Gen. Pl. 261 (1891).

Mamillaria rhodantha Link & Otto, Icon. t. 26 (1828-31) Mamillaria lanifera Haw. Phil. Mag. lxiii., 41 (), not Salm-Dyck (1850).

Oblong or subcylindric, 30 cm. or more high, 7.5 to 10 cm. in diameter, often forking from the middle: tubercles conical, 12 mm. long, 8 mm. in diameter, with woolly axils: radial spines 16 to 20, bristle-like, white, the lower longer (8 to 10 mm.); central spines 6 or 7, rigid, whitish with black tip, 12 mm.

long: flowers rose color, 12 mm. in diameter: fruit 2.5 cm. long, cylindrical. (Ill. l. c.) Type unknown.

Referred to Mexico in general, but reported as yet from San Luis Potosi to southern Mexico. Fl. profusely all summer.

Specimens examined: San Luis Potosi (Bourgeau 47; Pringle 3679; Eschanzier of 1891): also growing in Mo. Bot. Gard. 1893.

The specimens of Bourgeau and Pringle have somewhat larger spines than the type, as indicated by the description.

27. Cactus rhodanthus sulphureospinus.

Mamillaria sulphurea Forst. Handb. Cact. (1846), not Cactus sulphureus Gill, (1830).

Mamillaria rhodantha sulphurea Salm, Hurt. Cact. Dyck. 11 (1850).

Central spines sulphur-yellow; otherwise like the species. Type unknown.

San Luis Potosi.

Specimens examined: San Luis Potosi (Pfeiffer, with no number or date; Eschanzier of 1891).

The varietal distinction maintained seems a small one, but it is constant and striking, so far as can be discovered.

28. Cactus capillaris.

Mamillaria lanifera Salm, Cact. Hort. Dyck. 98 (1850), not Haw.

Cactus laniferus Kuntze, Rev. Gen. Pl. 250 (1891).

Cylindrical and erect: tubercles crowded, conical, glaucous, with axillary bristles: radial spines capillary and very numerous, white and crisped, entirely covering the plant; central spines 4 to 6, rigid, straight and spreading, straw-colored, 8 to 12 mm.

long: flowers equaling the tubercles, the yellow petals striped with red: fruit unknown. Type unknown.

Referred to Mexico in general, but definitely known only from Coahuila.

Specimens examined: Coahuila. (Palmer of 1880).

There is a confusion of synonymy between this species and C.

rhodanthus, both having been named Mamillaria lanifera. The earlier M. lanifera of Haworth, however, is clearly M. rhodantha of Link & Otto; and although Prince Salm-Dyck revived the name for the present species, the law of h.o.m.onyms will not permit it to stand. The name proposed refers to the abundant display of capillary radial spines, which is probably the most notable feature.

29. Cactus palmeri, sp. nov.

Cylindrical: tubercles crowded, glaucous, cylindrical (somewhat broadest above), about 4 mm. long, with dense axillary wool containing bristles: radial spines 25 to 30, very slender and white but rigid, about 5 mm. long, spreading or somewhat radiant, entangled with those of neighboring tubercles, and so covering the whole plant; central spines 3 to 5 (usually 4), more robust, erect or slightly divergent, brownish with darker tip, 7 to 8 mm.

long: flowers small: fruit clavate and scarlet: seeds black and strongly pitted, 0.5 to 0.8 mm. in diameter. Type, Palmer 921 in U. S. Nat. Herb.