98 
7. Cactus meiacanthus (Engelm.) Kuntze, Rev. Gen. Pl. 260 (1891). 
Mamillaria meiacantha Engelin. Syn. Cact. 263 (1856). 
Hemispherical or with depressed vertex, 7.5 to 12.5 em. in diame- 
ter, with a broad top-shaped base: tubercles compressed, 14 to 18 mm. 
long: radial spines 5 to 9 (usually about 6), stout and strongly subu- 
late, 6 to 10 mm. long, straight or somewhat curved, whitish or yellow- 
ish, the lower mostly a little longer, the upper one sometimes wanting; 
central spine shorter and stout, darker, straight, and porrect, turned 
upwards among the radials, or rarely wanting: flowers 2.5 to 3 em. 
long, reddish-white: fruit incurved, 2 to 3 em. long. (Ill. Cact. Mex. 
Bound. t. 9, figs. 1-3)—Type specimens are those of the collections ot 
1847, 1851, 1552, and 1853, from which the original description was 
drawn and all of which are in Herb. Mo. Bot. Gard. 
From the Guadalupe River, Texas, to the “ Great Bend” of the Rio 
Grande, westward through western Texas and New Mexico; also north- 
ern Mexico (Hemsley). FI. May, June. 
Specimens examined: TEXAS ( Wright of 1851, 1852; Bigelow of 1853): 
New Mexico (“Missouri Volunteers” of 1847; unknown collector in 
1880); also specimens cultivated in St. Louis in 1853, and others grow- 
ing in Mo. Bot. Gard. 1893. 
Dr. Englemann regarded this species as possibly only a variety of C. heyderi, to 
which it is certainly very closely allied through var. hemispherica, but the different 
tubercles and fewer stouter spines serve so well to distinguish it that it seems best 
to retain its specific rank. 
In reference to the citation of the original description an explanation seems neces- 
sary, Which will apply to numerous similar cases. The Pacif. R. Rep. iv. 27 (1856), 
Syn, Cact, 263 (1858), and Cact. Mex. Bound. 9 (1859), have each been cited as the 
original publication, The confusion has arisen from the fact that in both the publi- 
cations of 1856 the description in the Rep. Mex. Bound. is referred to, and in that 
report the plant is fully described as ‘‘sp. nov.” However, the publication of the 
Boundary Report was long delayed on account of the preparation of the plates, and 
in the ineantime both the publications of 1856 had appeared, in each one of which 
the species is distinctly characterized and reference made to the description in the 
forthcoming Boundary Report. As between the two publications of 1856 the Syn. 
Cact. (Proc. Amer. Acad. iii. 259) was evidently distributed first. 
8. Cactus gummiferus (Engelm.) Kuntze, Rev. Gen. Pl. 260 (1891). 
Mamillaria gunmifera Engelm, Wisliz. Rep. 21 (1848). 
Hemispherical, 7.5 to 12.5 em. broad and 6 to 10 em. high: tubercles 
12 to 15 mm. long: radial spines 10 to 12, the lower stout, with dusky 
apex, 12 to 15 mm. long, twice or thrice as long as the whitish setaceous 
upper ones; central spine (sometimes two) shorter (about 4 min.), stout, 
dusky and porrect: flowers 3 em. long, reddish-white, brownish-red 
outside: fruit unknown, (ZU, Cact. Mex. Bound. t. 9. figs. 18-20)— 
Type probably lost, as no specimens could be found in the Engelmann. 
Herbarium. 
Chihuahua, near Cosihuiriachi. 
So far as can be discovered, this species has not been collected since the original 
Wislizenus collection of 1846-47. The plants were cultivated by Dr. Engelmann 
