113 
upper one), stouter and longer (12 to 20 mm.), dark, mostly strongly 
recurved and appressed (rarely straightish): flowers about 3.5 cm. long, 
yellow (brownish-tinged outside): fruit unknown.—Type, Schott speci- 
mens in Herb, Mo. Bot. Gard. 
From Sonora to southern Mexico. Fl. June-August. 
Specimens examined: SoNoRA (Schott of 1855). 
43. Cactus salm-dyckianus (Scheer) Kuntze, Rev. Gen. P]. 261 (1891). 
Mamillaria salm-dyckiana Scheer in Salm, Cact. Hort. Dyck. 134 (1850). 
Subglobose: tubercles very broad and retuse, almost 2-parted by 
the tomentose groove, with axillary floceose wool: radial spines 7 or 8, 
very rigid, widely radiant, somewhat curved, 3 to 3.5 em, long, in older 
tubercles 3 to 6 additional slender and straight or twisted spines; the 
solitary central spine very stout, erect, almost 5 em. long: flowers and 
fruit unknown.—Type: Scheer says that this plant, brought from Chi- 
huahua by Potts, “unfortunately perished,” and the description was 
drawn from fragments, which in those days were not apt to be pre- 
served. 
Chihuahua. 
Specimens examined: Curmuanvua (“Salm of 1857”). 
The specimen referred to is in Herb. Mo, Bot. Gard., and reveals no additional 
characters; nor can the label be interpreted, except that it indicates that the speci- 
men is from plants cultivated successfully in the gardens of Prince Salm-Dyck,. 
+ + Flower and fruit remaining central in the very woolly vertex of the plant, 
++ Central spine solitary or wanting. 
44, Cactus compactus (Engelm.) Kuntze, Rev. Gen. Pl. 260 (1891). 
Mamillaria compacta Engelm. Wisliz. Rep. 21 (1848). 
Depressed-globose, 5 to 10 cm, in diameter, simple: tubercles short- 
conical, crowded, 8 mm. long: radial spines 13 to 16, rigid, recurved 
and appressed, interwoven with adjacent clusters, whitish or horny, 
10 to 20 mm. long; the erect central spine often wanting: flowers 3 to 
3.5 em. long and broad, yellow (brownish without): fruit oval, green: 
seeds 1.4 mm. long, smooth and yellow. (Ul. Cact. Mex. Bound. t. 74. 
fig. 2, seeds)—Type, Wislizenus of 1816 in Herb. Mo. Bot. Gard. 
Mountains of Chihuahua. Fl. June-July. 
Specimens examined: Coinvuanva (Wislizenus of 1846): also speci- 
meus cultivated in St. Louis in 1848, 1850, 1854. 
45, Cactus radians (DC.) Kuntze, Rey. Gen. PI. 261 (1891). 
Mamillaria radians DC, Rev. Cact. 111 (1829). 
Mamillaria pectinata Engelm, Syn. Cact. 266 (1856). 
Globose, 3.5 to 7.5 em. in diameter, simple: tubercles conical, from a 
4-angled base, lower ones short (4 to 6 mm.), upper tlower-bearing ones 
longer (10 to 12 mm.), terete and grooved: radial spines 16 to 24, some- 
what recurved from a bulbous compressed base, stiff and pectinate, 
horny or whitish (at length ashy), interwoven with adjacent clusters, 
those on lower tubercles about equal (6 to 10 mm.), on flower-bearing 
