Buiningia brevicylindrica.  This item ships in 2-3 weeks.

Carnegia gigantea (Saguaro). Sunset: 11-13,18-21; USDA: 9-10. Full sun. Heat tolerant. Little water. Hardy to 15°F. Grows to 50' tall. Native to the Sonoran desert of southwestern USA and Sonora state in Mexico. Seeds colected near Keary AZ. (approx. 10000 seeds= 23 grams)

Castellanosia caineana

Cephalocleistocactus ritteri. (Cleistocactus ritteri) USDA: 9b-10. Hardy to 32 F. Light shade in hot desert gardens. Shrubby growth to 3' tall, 1.2 " in diameter. Generous water summer, keep dry winter. Origin: Bolivia.

Cereus forbesii (Syn: Cereus validus). USDA: 9b-11. Hardy to 32° F, protect friom frost. Full sun. Columnar, branching growth to 14' tall, 5" in diameter. Moderate water summer, light water in winter. White nocturnal flowers, up to 3 inches long. Origin: Eastern Bolivia, Argentina.

Cereus peruvianus. Sunset:12-13,16,17,21-24; USDA: 9-11. Protect from hard freeze. Full sun. Heat tolerant. Moderate water, fertilize in summer. Treelike Growth to 20' tall. Large white nocturnal flowers, outer petals with pink or red highlights. Origin: Peru. 

Cereus peruvianus monstrosus. Sunset: 12-13,16,17,21-24; USDA: 9-11. Full sun. Heat tolerant. A mutated from of cereus peruvianus. Moderate water, fertilize in summer. Hardy to 26 deg. F. Grows to 15' tall. Origin: Peru.

Cereus species mix. Including Cereus aethiops, Cereus dayamii, Cereus forbesii, Cereus peruvianus.

Chileorebutia monteamargensis.

Cleistocactus acanthurus (Synonym: Loxanthocereus acanthurus)

Cleistocactus baumannii. Red tubular flowers, attracts hummingbirds.

Cleistocactus bruneispinus

Cleistocactus candelilla (Synonym: Cleistocactus candelilla var. pojoensis,
Cleistocactus vallegrandensis)