Autor: Backeberg

Genus native of the province of Islay, department of Arequipa, in Peru, where the genus was first found.
A genus of globose to shortly cylindrical plants, the apex wooly, with fibrous roots or turbiniform. Thick central spines and undefined radials.
Flowers diurnal, sometimes self-fertile, pale yellow to sulphur yellow, pollinated by hymenoptera. Fruits clavate to elongated like a balloon, hollow, thin-walled, pink to red. Seeds black, subglobose, tuberculate, covered with mucilage.
The genus Islaya grows between Peru and Chile, along the Pacific coast, an extremely arid area, in full sun, on very poor mineral soils, sandy or even gypsum (clastic sediments), but takes advantage of the coastal fog, the garъa in Peru, or the camanchaca in Chile. It is found from sea level up to 1050 m in altitude. Some species such as Islaya islayensis are in great danger of extinction, probably due to climate change.
Chile (Antofagasta, Tarapaca), Peru (Arequipa, Moquegua, Lima, Tacna).

Currently 5 species + and possible subspecies:
– Islaya Iquiquensis (F.Ritter) Faundez & R.Kiesling 2007
– Islaya islayensis* (Foster) Backeb. 1934
– Islaya mollendensis Backeberg 1935
– Islaya omasensis Ostolaza & Mischler 1983
– Islaya unguispina F.Ritter 1981

References: "TAXONOMY of the CACTACEAE" -  ISBN 978-84-617-3723-9 (Vol. 1)