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, except that it indicates that the specimen 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 cm. long and broad, yellow (brownish without): fruit oval, green: seeds 1.4 mm. long, smooth and yellow. (Ill. Cact. Mex. Bound. t. 74. fig. 2, seeds) Type, Wislizenus of 1846 in Herb. Mo. Bot. Gard.
Mountains of Chihuahua. Fl. June-July.
Specimens examined: Chihuahua (Wislizenus of 1846): also specimens cultivated in St. Louis in 1848, 1850, 1854.
45. Cactus radians. (DC.) Kuntze, Rev. Gen. Pl. 261 (1891).
Mamillaria radians DC. Rev. Cact. 111 (1829).
Mamillaria pectinata Engelm Syn. Cact. 266 (1856).