preceding year, while the later ones develop from the axils of
the first tubercles of the same season. The specimen growing in
Mo. Bot. Gard, in 1893 had 3 central spines, one or two being
hooked.

19. Cactus grahami (Engelm.) Kuntze, Rev. Gen. Pl. 260 (1891).

Mamillaria grahami Engelm. Syn. Cact. 262 (1856).

Globose or at length ovate, 2.5 to 7.5 cm. high, simple or
branched from the base and even cespitose: tubercles ovate, 6 mm.
long, dilated at base (corky and persistent when old), with naked
axils: radial spines 15 to 30 in a single series, white, often
dusky-tipped, slender but rigid, naked or puberulent, 6 to 12 mm.
long, the shorter ones uppermost, the longer ones lateral;
central spines 1 to 3, blackish from a paler base, the lower
(often the only) one stouter and longer (6 to 18 mm.), hooked
upward, the one or two upper ones (when present) shorter and
slenderer, divergent: flowers 2 to 2.5 cm. long, rose-colored:
fruit 2 to 2.5 cm. long: seeds 0.8 to 1 mm. long, black and
pitted. (Ill. Cact. Mex. Bound. t. 6. figs. 1-8) Type, Wright
of 1852 and Bigelow of 1852 in Herb. Mo. Bot. Gard.

In rocky places, from the mountains of extreme southwestern Texas
(west of the Pecos) to southern Utah, southern California (common
along the Colorado), and Sonora. Fl. June-August.

Specimens examined: Texas (Wright of 1852; Newberry of 1858; G.
R. Vasey of 1881; Miller of 1881; Briggs of 1892): New Mexico
(Evans of 1891): Arizona (Bigelow of 1852; Schott of 1858; Cous