Cleistocactus

Cleistocactus is a genus of flowering plants in the cactus family Cactaceae, native to mountainous areas – to 3,000 m (9,843 ft)[1] – of South America (Peru, Uruguay, Bolivia and Argentina). The name comes from the Greek kleistos meaning closed because the flowers hardly open.

The stems of these cacti are tall, mostly slender and often many-branched with numerous ribs with closely set areoles and spines. The flowers are tubular and the tips hardly open with only the style and stamens usually protruding.

Species and subspecies
Cleistocactus acanthurus (Vaupel) D.R.Hunt
Cleistocactus acanthurus subsp. acanthurus
Cleistocactus acanthurus subsp. faustianus (Backeb.) Ostolaza
Cleistocactus acanthurus subsp. pullatus (Rauh & Backeb.) Ostolaza
Cleistocactus baumannii (Lem.) Lem.
Cleistocactus baumannii subsp. anguinus (Gürke) P.J.Braun & Esteves
Cleistocactus baumannii subsp. baumannii
Cleistocactus baumannii subsp. chacoanus (F.Ritter) P.J.Braun & Esteves
Cleistocactus baumannii subsp. croceiflorus (F.Ritter) P.J.Braun & Esteves
Cleistocactus baumannii subsp. horstii (P.J.Braun) N.P.Taylor
Cleistocactus baumannii subsp. santacruzensis (Backeb.) Mottram
Cleistocactus brookeae Cárdenas
Cleistocactus buchtienii Backeb.
Cleistocactus candelilla Cárdenas
Cleistocactus chotaensis F.A.C.Weber ex Rol.-Goss.
Cleistocactus clavispinus (Rauh & Backeb.) Ostolaza