Origin and Habitat: Catamarca, Argentina
Habitat: Argentina is a land erupting in volcanic fire, quickly changing to the glacial cold of the Andes. Nearby is the most arid desert in the world, the desolate Puna de Atacama. Inhabitants must be very rugged in order to tolerate such extremes in exposure. Trichocereus grandiflorusSN|1027]]SN|1027]] is such a robust individual.

• Echinopsis grandiflora Linke

• Echinopsis calochlora K.Schum.
• Lobiviopsis calochlora (K.Schum.) Frič
• Echinopsis calochlora var. claviformis Rud.Mey.
• Echinopsis calochlora subs. glaetzleana P.J.Braun & Esteves
• Echinopsis grandiflora Linke

Description: It is a basally branching columnar cactus, up to 90 cm tall.
Stems: 5-8 cm, in diameter.
Ribs: 12 to 18.
Areoles: Whitish brown.
Central spines: 1 to 2 , up to 6 cm long.
9 to 11 brownish
Radial spines: Up to 4 cm inches long.
Flowers: 7-10 cm long, bright red produced near the end of the stems. Throat dark red, filaments fuchsia . Anthers clear pastel and stigma pure white.

Notes: The main form of Trichocereus grandiflorusSN|18495]]SN|1027]] has red flowers in summer, but forms with orange and yellow (Trichocereus huaschaSN|1027]]SN|18495]] var. macrantha) flowers are also found.
This columnar species has been the subject for years of intensive selective hybridization with hybrids of Echinopsis. As a result hybrids (see: Trichopsis) now flower in a vast array of colours, including yellow, rose, crimson, orange, violet, white and even bicolour. Flowers can attain 22cm in diameter, rivalling even the giant flowers of the epiphytic "Orchid Cacti" (Epiphyllums). T. grandiflorus hybrids in time form attractive columns that explode yearly in vivid floral displays. Very few cacti can surpass the flowers of the T. grandiflorus hybrids for sheer flower power.

Cultivation and Propagation: Suited for full sun, needs little water in summer, no in winter. It is quite frost hard (to -10°C) Plants grown in the ground form soon imposing specimens. Usually propagated by cuttings or seeds. The flower colour is not always true from seeds