appressed (rarely straightish): flowers about 3.5 cm. long,
yellow (brownish-tinged outside): fruit unknown. Type, Schott
specimens 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. Pl. 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 floccose wool: radial spines
7 or 8, very rigid, widely radiant, somewhat curved, 3 to 3.5 cm.
long, in older tubercles 3 to 6 additional slender and straight
or twisted spines; the solitary central spine very stout, erect,
almost 5 cm. long: flowers and fruit unknown. Type: Scheer says
that this plant, brought from Chihuahua by Potts, "unfortunately
perished," and the description was drawn from fragments, which in
those days were not apt to be preserved.

Chihuahua.

Specimens examined: Chihuahua ("Salm of 1857 ").

The specimen referred to is in Herb. Mo. Bot. Gard., and reveals
no additional characters; nor can the label be interpreted,