Origin and Habitat: Totoral Bajo to Carrizallilo, Huasco, Coquimbo and Atacama regions, Chile (extent of occurrence about 5,000 km2)
Altitude: It grows at elevations of 0 to 800 m asl.
Habitat and Ecology: Eriosyce villosaSN|3030]]SN|3030]] occurs in coastal hills (lomas costeras) on rocky soils together with Neochilenia napina. It is frequent and the population stable. The major threats are illegal collection and industrialization to process steel.

• Neoporteria polyraphis (Pfeiff. ex Salm-Dyck) Backeb.
• Bridgesia polyraphis (Pfeiff. ex Salm-Dyck) Backeb.
• Chileniopsis polyrhaphis (Pfeiff.) Backeb. in Backeb. & F.M.Knuth
• Echinocactus polyrhaphis (Pfeiff. ex Salm-Dyck)
• Neoporteria polyraphis (Pfeiff. ex Salm-Dyck) Backeb.

• Eriosyce villosa (Monv.) Katt.
• Bridgesia villosa Backeb.
• Cactus villosus Monv.
• Chileniopsis villosa (Monv.) Backeb. in Backeb. & F.M.Knuth
• Euporteria villosa (Monv.) Kreuz. & Buining
• Neoporteria villosa (Monv.) A.Berger
• Chileniopsis villosa var. nigra (A.Berger ex A.Berger) Y.Itô
• Chileniopsis villosus var. niger A.Berger
• Neoporteria polyraphis (Pfeiff. ex Salm-Dyck) Backeb.
• Bridgesia polyraphis (Pfeiff. ex Salm-Dyck) Backeb.
• Chileniopsis polyrhaphis (Pfeiff.) Backeb. in Backeb. & F.M.Knuth
• Echinocactus polyrhaphis (Pfeiff. ex Salm-Dyck)
• Neoporteria polyraphis (Pfeiff. ex Salm-Dyck) Backeb.
• Neoporteria villosa var. atrispinosa (Backeb.) Donald & G.D.Rowley
• Chilenia atrispinosa Backeb.
• Euporteria atrispinosa Kreuz. & Buining
• Neoporteria atrispinosa Backeb.
• Neoporteria villosa var. cephalophora (Backeb.) Donald & G.D.Rowley
• Chilenia cephalophora Backeb.
• Euporteria cephalophora Kreuz. & Buining
• Neoporteria cephalophora Backeb.
• Neoporteria villosa var. laniceps (F.Ritter) A.E.Hoffm.
• Neoporteria laniceps F.Ritter
• Neoporteria planiceps F.Ritter

Description: Eriosyce villosaSN|3030]]SN|3030]] var. polyraphis much better known under its old name, Neoporteria polyraphis, is now considered nothing else than Eriosyce villosaSN|3030]]SN|3030]], but the plants in cultivation are not exactly the same, the spines are a little shorter and the flowers are a bit more pointed.
Note: The number of spines (especially the bristly or hairy radials) in Eriosyce villosaSN|3030]]SN|3030]] shows a certain degree of variability depending on origin. The otherwise similar features of “var. villosa” and “var. polyraphis”, namely size and form of stems, flowers, fruit, etc., prove, that is impossible to differentiate between these taxa.
Habit: It is a small solitary cactus densely folded by bristly spines.
Stem: Subglobose to Globose becoming elongated, green or very dark green (almost black) or dark red, up to 15 cm tall, 8 cm in diameter.
Roots: Large tuberose tap-root.
Ribs: 13-15 Deeply notched between areoles.
Spines: ± dense, long, glassy gold-brownish to black central spines with thin bristle like grey radials.
Flowers: Bright magenta, borne on young areoles, 2-2,5 cm in diameter, Pericarpels and floral tubes with long wool and gassy white bristles.
Blooming time: Blooms early in the year. Occasionally forms some buds late in the previous year, and it can sometimes flower during the winter, although the main burst of flowering is in April.
Fruits: Elongate, red, dehiscing by basal pores.

Bibliography: Major references and further lectures
1) Faundez, L., Guerrero, P., Saldivia, P. & Walter, H.E. 2013. Eriosyce villosa. In: IUCN 2013. “IUCN Red List of Threatened Species.” Version 2013.2. <www.iucnredlist.org>. Downloaded on 16 January 2014.
2) Fred Kattermann “Eriosyce (Cactaceae): The Genus Revised and Amplified” David Hunt, 1994
3) Edward Anderson “The Cactus family” Timber Press, Incorporated, 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
5) David R Hunt; Nigel P Taylor; Graham Charles; International Cactaceae Systematics Group. "The New Cactus Lexicon" dh books, 2006
6) Hans Hecht “BLV-Handbuch der Kakteen” BLV-Verlagsgesellschaft, 1982

Cultivation and Propagation: It is a summer grower species. Easy to cultivate but somewhat rot prone if kept in a non ventilated place. Requires a very fast draining drying soil. Water regularly in summer, but do not overwater.
Needs a full sun exposure (or light shade) Good heat tolerance. Hardy to at down to -5°C for brief periods.
Propagation: Usually propagated from Seeds. (seldom produces offsets)