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
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.
subspecies, varieties and forms:
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
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
spines and few ribs (Copiapo and Totoral Bajo)