100 
Specimens examined: Texas (Wright 121, also of 1852; Parry af 
1852): ARIZONA (Miller of 1881): CnimuAmuA (Pringle 213, 250, 258): 
also specimens cultivated in St. Louis in 1852 and 1855. 
11. Cactus lasiacanthus denudatus (Engelm.). 
Mamillaria lasiacantha denudata Engel, Cact, Mex. Bound.5 (1859). 
Larger, 2.5 to 3.5 em. in diameter, with longer tubercles (5 to 6 mm.), 
and more numerous (00 to 80) longer (3 to 5 mm.) spines which are 
naked or nearly so. (///, Cact. Mex. Bound. t. 4)—Type, Wright spec- 
imen in Herb. Mo. Bot. Gard. 
From western Texas (with the species) to Coahuila. 
Specimens examined: TEXAS ( Wright of 1852): CoAHUILA (Palmer 
of 1880). 
In the Syn. Cact. Dr. Engelmann merges this variety with the species, and has 
been followed in this by subsequent writers, but the characters seem so distinctive 
that its varietal rank has been restored. 
12. Cactus micromeris (Engelm.) Kuntze, Rev. Gen, Pl, 260 (1891). 
Mamillaria micromeris Engelm. Syn. Cact. 260 (1856). 
With depressed top and very rarely branching, 1 to 3.5 em. in diame- 
ter: tubercles very small (about 1 mm, long) and wart-like, erowded, 
shedding the spines with age and giving the base of the plant a tuber- 
culated appearance: spines from white to ashy-gray, 1 to 3 mm. long; 
in young plants and on lower tubercles of adult plants about 20, equal 
and radiant; on flower-bearing tubercles 30 to 40, stellate-porrect in 
every direction, the 6 to 8 upper ones two to four times longer than the 
rest (4 to 8 mm.), clavate toward the apex and acute (the clavate top 
at length deciduous), intermixed with loose wool of about the same 
length and forming a small tuft on the top of the plant whieh includes 
and partly hides flowers and fruit: flowers whitish to light pink, almost 
central, very small (6 mm. in diameter), much reduced (3 to 5 sepals, 
5 petals, 10 to 15 stamens, 3 stigmas): fruit 8 to 12 mm. long: seeds 
1.5 mm. long, black and shining, (Jl. Cact. Mex. Bound. t. 1 and 2. 
figs. 1-4)—Type, the specimens of Wright in Herb. Mo. Bot. Gard. 
On naked mountain tops and sides, extreme southwestern Texas (Val 
Verde County to i} Paso) and southward into Coahuila and Chihuahua. 
Specimens examined: TEXAS (Wright 227 of 1849, also of 1852; Neal- 
ley of 1892): COAHUILA (Bigelow of 1853): CummUAHUA (Pringle 212): 
also growing in Mo. Bot. Gard. 1893. 
The plants densely covered above with delicate ashy-gray spines and with naked 
tuberculate base are readily recognized, Itstill remains an open question whether the 
flowers are developed from the axils of tubercles of the same season or the last ones 
of the preceding season. Dr, Englemann inclined to the latter view, as all the other 
characters of the plant associate it with the ‘“lateral-flowered” species; and inthe 
absence of definite observation we have retained it there. If the nearly central 
flowers indicate that they are produced from growth of the same season the species 
would seem to be allied to CORYPHANTHA, in which group its small flowers and small 
tubercles would be anomalous. 
