nov.

Mamillaria Setispina Engelm. Mss.

Fasciculate and ascending, simple or branched at base, the stems about 30 cm. high and 3 to 6 cm. in diameter, densely covered with remarkably long stout spines: tubercles short and broadly conical, with axillary wool: spines white. with black tips; radials 10 to 12, widely spreading, very unequal, 10 to 34 mm. long, slender and flexuous; central spines 1 to 4, more rigid and much longer (20 to 50 mm.), the upper ones straight, the lowest one longest and hooked (usually upwards) and often variously curved and twisted: fruit obovate and scarlet 30 mm. long: seeds, black and pitted. Type, Gabb 15 in Herb. Mo. Bot. Gard.

Rocky or gravelly soil, San Julio Canyon. and in the vicinity of
San Borgia, Lower California.

Specimens examined: Lower California (W. M. Gabb 15 of 1867, at
San Borgia; Brandegee of 1889, from San Borgia and San Julio
Canyon).

In his notes Mr. Gabb describes the flower as "large, 3 to 3.5 inches long, bell-shaped, of a beautiful purplish red color," concerning which Dr. Engelmann remarks "this would indicate a Coryphanth, but the tubercles show no trace of a groove, and, moreover, a withered remnant of a flower laterally attached (say 18 to 20 mm. long), so that I have no doubt that Mr. Gabb's statement is founded on some error." It is very probable that the flowers are scarlet and larger than Dr. Engelmann suggests. The species is closely allied to C. roseanus, but differs in its shorter tubercles and much longer spines. About a dozen stems rise in a clump, about a foot high, covering an area of 2 or 3 feet. These two species represent a very distinct Lower Californian group of cylindrical and hooked Eumamillarias. Both probably have showy scarlet flowers and may attain considerable length when growing upon rock ledges so as to become pendent. The specimens of C. setispinus from San Julio Canyon are from younger parts and show but a single long and hooked central. The San Borgia specimens show mostly 3 or 4 centrals, the lowest one hooked and becoming remarkably long and often variously twisted and curved. However, I can discover no difference except such as may be due to age.

  ++ Central spines present and not hooked.
  + Central spines more than one, longer than the radials, which
    are numerous, white and slender (capillary or bristle-like)
    (rigid in C. Halei).

25. Cactus halei (Brandegee).

Mamillaria halei Brandegee, Proc. Calif. Acad. Sci Scr. 2. ii. 161 (1889).

Stems cylindrical, 8 to 10 in a clump, about 30 cm. high and 5 to 7.5 cm. in diameter: tubercles short, with axillary wool: radial spines 10 to 22, rigid and erect-spreading, unequal, 6 to 15 mm. long; central spines numerous and erect-spreading, 1 to 3 of them very stout and prominent (25 to 35 mm. long); all the spines straight, at first reddish-brown, becoming yellowish and ashy, more or less dark-tipped: flowers 2.5 cm. long, bright scarlet (almost throughout): fruit 12 mm, long, clavate and red: seeds black and pitted. (Ill. l. c. t. 6) Type in Herb. Calif. Acad.

Abundant on Magdalena and Santa Margarita Islands, western coast of Lower California. Fl. January.

Specimens examined: Lower California (Brandegee of 1889, on
Magdalena Island).

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 homonyms 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.

San Benito Island, off the west coast of lower California.

Specimens examined: Lower California, San Benito Island (Palmer 921 of 1889, reported as Mamillaria Goodrichii).

Very closely allied to C. capillaris of eastern Mexico.

30. Cactus stellatus Willd. Enum. Suppl. 30 (1813).

  Cactus pusillus DC. Cat. Hort. Monsp. 184 (1813), not Haw.
    (1803).