Origin and Habitat: Echinocereus viridiflorusSN|11071]]SN|11071]] occurs in Kansas, New Mexico, Oklahoma, South Dakota, Texas and Wyoming (United States). Scientific literature also reports it from the Mexican states of Chihuahua and Coahuila, and Colorado in the United States. It occurs farther north than any other member of the genus, into the cooler regions of the Great Plains grassland, as far as South Dakota and to the Mountainous areas of New Mexico and central Colorado.
Altitude range: It grows at elevations of 900 to 2,700 metres above sea level.
Habitat and Ecology: Echinocereus viridiflorusSN|11071]]SN|11071]] grows in grasslands, mountain parklands and pinyon and juniper woodland in gravelly soils of foothills, plains, and washes in grassland or along edges of woodlands. It is wide-ranging, abundant, and there are no major threats. Furthermore, it occurs in many protected areas. Hence, it is listed as Least Concern. The species is used as an ornamental and it is cultivated for that purpose.

• Echinocereus viridiflorus Engelm. in Wisliz.
• Cereus viridiflorus (Engelm.) Engelm.

• Echinocereus viridiflorus Engelm. in Wisliz.
• Cereus viridiflorus (Engelm.) Engelm.
• Echinocereus labouretii Förster ex Rümpler
• Echinocereus viridiflorus var. centrispinus Vernon Bailey
• Echinocereus viridiflorus var. elongatus* hort. ex Backeb.
• Echinocereus viridiflorus var. faciliflorus Hildm. ex Schelle
• Echinocereus viridiflorus var. intermedius Backeb.
• Echinocereus viridiflorus var. longispinus Schelle
• Echinocereus viridiflorus var. major
• Echinocereus viridiflorus var. minor Engelm. ex D.Weniger
• Cereus viridiflorus var. minor Engelm.
• Echinocereus viridiflorus var. montanus hort.
• Echinocereus viridiflorus var. robustior Kuenzler
• Echinocereus viridiflorus var. ruberrimus Frič
• Echinocereus viridiflorus var. rubrus Frič
• Echinocereus viridiflorus var. sanguineus Regel ex Schelle
• Echinocereus viridiflorus var. standleyi (Britton & Rose) Orcutt ex D.Weniger
• Echinocereus standleyi Britton & Rose
• Echinocereus viridiflorus f. standleyi (Britton & Rose) D.Parker

• Echinocereus viridiflorus subs. chloranthus (Engelm.) N.P.Taylor
• Cereus chloranthus Engelm.
• Echinocereus chloranthus (Engelm.) Engelm. ex Rümpler in Förster
• Echinocereus viridiflorus var. chloranthus (Engelm.) Backeb.
• Echinocereus viridiflorus f. chloranthus Krainz
• Echinocereus milleri W.Blum, Kuenzler & Oldach
• Echinocereus viridiflorus var. canus A.M.Powell & Weedin
• Echinocereus viridiflorus var. neocapillus (D.Weniger) A.D.Zimmerman
• Echinocereus chloranthus var. neocapillus D.Weniger
• Echinocereus neocapillus (D.Weniger) W.Blum & Mich.Lange in W.Blum et al.

• Echinocereus viridiflorus subs. correllii (L.D.Benson) W.Blum & Mich.Lange in W.Blum et al.
• Echinocereus chloranthus subs. cylindricus f. corellii (L.D.Benson)
• Echinocereus correllii Kuenzler
• Echinocereus viridiflorus var. correllii L.D.Benson
• Echinocereus carmenensis W.Blum, Mich.Lange & E.Scherer in W.Blum et al.

• Echinocereus viridiflorus subs. cylindricus (Engelm.) N.P.Taylor
• Cereus viridiflorus var. cylindricus Engelm.
• Cereus viridiflorus var. tubulosus J.M.Coult.
• Echinocereus chloranthus subs. cylindricus (Engelm.) W.Blum & Mich.Lange in W.Blum et al.
• Echinocereus chloranthus var. cylindricus (Engelm.) N.P.Taylor
• Echinocereus strausianus Haage jr. in Quehl
• Echinocereus viridiflorus var. cylindricus (Engelm.) Rümpler
• Echinocereus viridiflorus var. tubulosus (J.M.Coult.) A.Heller

• Echinocereus viridiflorus subs. davisii (Houghton) N.P.Taylor
• Echinocereus davisii Houghton
• Echinocereus viridiflorus var. davisii (Houghton) W.T.Marshall
• Echinocereus viridiflorus f. davisii (Houghton) Krainz

• Echinocereus viridiflorus var. rhyolithensis W. Blume & Mich.Lange
• Echinocereus chloranthus subs. rhyolithensis W.Blum & Mich.Lange in W.Blum et al.
• Echinocereus viridiflorus cowperii n.n.
• Echinocereus cowperii n.n.

• Echinocereus viridiflorus subs. davisii cv. brevispinus hort.
• Echinocereus davisii f. brevispinus hort.

Description: E. viridiflorus is a compless that comprises a large number of infraspecific taxa, differing in various combinations of flower color, spine color, number and thickness of central spines, and other characters, including floral scent. Wherever such taxa are sympatric they intergrade; all are freely interfertile in the greenhouse.
There are numerous varieties and subspecies. The following subspecies are currently recognized: the nominate form, subsp. chloranthus (Engelm.) N.P.Taylor, subsp. correllii (L.D.Benson) W.Blum & Mich.Lange, subsp. cylindricus (Engelm.) N.P.Taylor, and subsp. davisii (Houghton) N.P.Taylor.

Notes: Echinocereus viridiflorusSN|11085]]SN|11071]] in the broad sense may prove paraphyletic with respect to Echinocereus davisiiSN|11071]]SN|11085]], but they are phenologically isolated, with E. davisii flowering earlier and thus appearing reproductively isolated in the wild.

Bibliography: Major references and further lectures
1) David Hunt, Nigel Taylor “The New Cactus Lexicon” DH Books, 2006
2) Heil, K., Terry, M. & Corral-Díaz, R. 2013. Echinocereus viridiflorus. The IUCN Red List of Threatened Species. Version 2014.3. <www.iucnredlist.org>. Downloaded on 28 November 2014.
3) Edward F. Anderson “The Cactus Family” Timber Press, 2001
4) James Cullen, Sabina G. Knees, H. Suzanne Cubey “The European Garden Flora Flowering Plants: A Manual for the Identification of Plants Cultivated in Europe, Both Out-of-Doors and Under Glass” Cambridge University Press, 11/Aug/2011

Cultivation and Propagation: In culture E. viridiflorus is without problems and regularly shows its small green flowers if we provide an adequate winter rest period. It is sensitive to overwatering (rot prone) needs good drainage, Keep drier and cool in winter. Need full sun; Very cold resistant hardy to -20° C or less for short periods of time.
Propagation: Seeds or cutting (if available)