Eriosyce  atroviridis (atrovirens)
(Syn: Eriosyce crispa ssp. atroviridis var. atroviridis)

Eriosyce (Neoporteria) crispa subsp. atroviridis var. atroviridis
This species has showy dull-white or brownish blooms, tannish-green stems and long thin spines.
 

Description: Solitary cactus with showy dull-white or brownish blooms, tannish-green stems and long thin spinesthat are not easily distinguished as centrals or radials. This species is quite variable and of very controversial classification.
Stem: Flattened, sub-globular or shortly cylindrical 9-14 cm in diameter, glaucous-green, dark olive green to tannish-green.
Ribs: 13-17 in adult specimen about 7-12 mm tall, tubercled.
Areoles: 5-20 mm apart.
Radial spines: 10 to15, about 1,5-4 cm long, needle-like and more or less curved inward, pale yellowish, brownish or dark grey with a darker tip.
Central spines: 1 to 7 slightly stronger, 2 to 5 cm long,
Root: Fibrous to tuberose often separated by a narrower neck.
Flower: Up to 3,5 cm long and broad, funnel-form, diurnal, produced by younger areoles at the woolly apex, dull white to pale brow. Pericarpel and floral tube with bracts, wool and bristles.
Fruit: 2 x 1,5 cm, more or less elongated, green or reddish-green, deishing by basal pores.
Seeds: 1,25 mm.

Recognized subspecies, varieties and forms:

subsp. crispa with hairlike, contorted black spines not easily distinguishable as radiald and centrals. (Origin West of Freirina)
subsp. atroviridis var. atroviridis with needle like and 12-14 radial spines (Origin Vallenar and Freirina)
subsp. atroviridis var. carrizalensis with stif needlelike spines, 12-13 radial spines and approx 15 ribs (Origin:Carrizal and Carrizal Bajo)
subsp. atroviridis var. huascensis With stiff, needle like spines, and few (6-8) radial spines and only 10-12 ribs. (Origin: East of Huasco)
subsp. atroviridis var. totoralensis with twisted spines and few ribs (Copiapo and Totoral Bajo)

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Scientific name: Eriosyce atroviridis (atrovirens)

Nowadays regarded as: Eriosyce crispa ssp. atroviridis var. atroviridis (F.Ritter) Katt. 1994

Origin: Chile, Atacama (Vallenar and Freirina )

Habitat: It grows in costal areas where very little else grows. It's a very drought tolerant species. Despite the lack of rain where it lives, the extreme aridity is attenuated by the frequent, often dense, coastal fogs. The fog tends to concentrate in the form of a cloud band at an estimated height of 500 to 850 m. It shows a recurrent pattern; usually it is overcast in the early mornings, the clouds dissipating during the late morning and returning during the late afternoons. The plant grows often buried in the ground and is almost impossible to spot without the flowers.

Conservation status: Listed in CITES appendix 2.

Synonyms:

• Pyrrhocactus atroviridis F.Ritter [Basionym]
  In: Succulenta 89 1960.
• Horridocactus atroviridis (F.Ritter) Backeb.
  In: Cactac. Handb. Kakteenk. 6: 3793 1962
• Neochilenia nigriscoparia
• Neoporteria atrovirens
• Neoporteria atroviridis (F. Ritter) R.M. Ferryman., R. & K. Preston-Mafham
  In: Cacti: illus. dict.: 140: 1991
• Eriosyce eriosyzoides ssp. atroviridis
• Neoporteria tuberisulcata var. atroviridis (F.Ritter) Donald et G.D.Rowley
  In: Cact. Succ. J. (GB) 28: 58 1966.
• Neoporteria atroviridis (F.Ritter) Ferryman, Preston-Mafham
  In: Cacti: illus. dict. 140 1991.
• Eriosyce crispa var. atroviridis  (F.Ritter) F.Kattermann1994
• Neoporteria vallenarensis var. atroviridis
   

Cultivation:  This slow growing cactus is kept for the beauty of its form and flowers. It is a summer grower species. Easy to cultivate but somewhat rot prone if kept in a non ventilated place. Require a very fast draining drying soil, water regularly in summer, but do not overwater.
Needs a full sun exposure, but must be protected from excessive heat and sun in summer, and seems to do best in cultivation with a bit of shade.  Good heat tolerance. Keep warm and dry in winter (5 to10°C) to avoid rot.  Not highly tolerant of a great deal of frost. (Frost tolerance -5°C or less for shot periods)

Propagation: Usually propagated from Seeds. (seldom produces offsets)
Grafting is sometime used to speed growth rate and to create a back-up to plants in collection.

Photo of conspecific taxa, varieties, forms and cultivars of plants belonging to the Eriosyce crispa complex (This Taxon has lots of synonyms  whit several controversial varieties and subspecies and comprises a multitude of different forms, but where each form is linked to others by populations of plants with intermediate characteristics):

• Eriosyce crispa
• Eriosyce atroviridis (E. crispa ssp. atroviridis var. atroviridis)