Origin and Habitat: Camana Pampa, Peru.
Altitude range: 400-600 metres above sea level.

• Islaya solitaria n.n.

• Eriosyce islayensis (C.F.Först.) Katt.
• Echinocactus islayensis C.F.Först.
• Islaya islayensis (C.F.Först.) Backeb.
• Malacocarpus islayensis (C.F.Först.) Britton & Rose
• Neoporteria islayensis (C.F.Först.) Donald & G.D.Rowley
• Parodia islayensis (C.F.Först.) Borg
• Eriosyce islayensis subs. grandis (Rauh & Backeb.) G.J.Charles
• Islaya grandis Rauh & Backeb. in Backeb.
• Islaya islayensis subs. grandis (Rauh & Backeb.) G.J.Charles
• Neoporteria islayensis var. grandis (Rauh & Backeb.) Donald & G.D.Rowley
• Eriosyce islayensis subs. omasensis (Ostolaza & Mischler) G.J.Charles
• Eriosyce omasensis (Ostolaza & Mischler) Ostolaza
• Islaya omasensis Ostolaza & Mischler
• Neoporteria omasensis (Ostolaza & Mischler) Ferryman
• Islaya bicolor Akers & Buining
• Neoporteria bicolor (Akers & Buining) Donald & G.D.Rowley
• Islaya brevicylindrica Rauh & Backeb.
• Neoporteria islayensis f. brevicylindrica (Rauh & Backeb.) Donald & G.D.Rowley
• Islaya copiapoides Rauh & Backeb.
• Neoporteria islayensis var. copiapoides (Rauh & Backeb.) Donald & G.D.Rowley
• Islaya copiapoides var. chalaensis F.Ritter
• Islaya chalaensis F.Ritter
• Islaya copiapoides var. pseudomollendensis F.Ritter
• Islaya divaricatiflora F.Ritter
• Neoporteria islayensis var. divaricatiflora (F.Ritter) Donald & G.D.Rowley
• Islaya flavida F.Ritter
• Islaya grandiflorens Rauh & Backeb.
• Neoporteria islayensis f. grandiflorens (Rauh & Backeb.) Donald & G.D.Rowley
• Islaya grandiflorens var. spinosior Rauh & Backeb.
• Neoporteria islayensis f. spinosior (Rauh & Backeb.) Donald & G.D.Rowley
• Islaya grandiflorens var. tenuispina Rauh & Backeb.
• Islaya grandis var. brevispina Rauh & Backeb.
• Islaya grandis var. neglecta A.Simo
• Islaya islayensis var. minor (Backeb.) F.Ritter
• Islaya minor Backeb.
• Neoporteria islayensis f. minor (Backeb.) Donald & G.D.Rowley
• Islaya krainziana F.Ritter
• Neoporteria krainziana (F.Ritter) Donald & G.D.Rowley
• Islaya longicarpa Kníže
• Islaya maritima F.Ritter
• Islaya minuscula F.Ritter
• Islaya molendensis (Vaupel) Backeb.
• Echinocactus molendensis Vaupel
• Neoporteria islayensis f. molendensis (Vaupel) Donald & G.D.Rowley
• Islaya paucispina Rauh & Backeb.
• Islaya paucispina var. curvispina Rauh & Backeb.
• Neoporteria lindleyi f. curvispina (Rauh & Backeb.) Donald & G.D.Rowley
• Islaya paucispinosa Rauh & Backeb.
• Islaya solitaria n.n.
• Islaya unguispina F.Ritter
• Neoporteria lindleyi C.F.Först.
• Echinocactus lindleyi C.F.Först.

• Eriosyce islayensis cv. TAIWAN
• Islaya cv. TAIWAN

Description: Islaya solitariaSN|32696]]SN|32696]] n.n. is an undescribed name used commercially to indicate one of the local forms of Eriosyce islayensisSN|1713]]SN|1713]], which is a small cactus with very woolly areoles and dark spreading spines. The morphological or geographical form labelled Islaya solitariaSN|32696]]SN|32696]] is a often solitary (hence the specific name), spherical or short cylindrical plant up to 20 cm tall and about 10 cm in diameter. It has been found by the commercial collector Karel Kníže who spread it under no. KK 677. Eriosyce islayensisSN|1713]]SN|1713]] is indeed very variable and has received many names, but it is clear from fieldworks that the different wild populations constitute a single but multiform species. Islaya solitariaSN|32696]]SN|32696]] should be included within (as a synonym of) Eriosyce islayensisSN|1713]]SN|1713]], suggesting that there is not really a fundamental difference between the two.
Stem: Solitary, spherical or cylindrical to 20 cm tall and 10 cm thick, lime-blue or grey-green.
**Ribs: Usually 15-20, swollen where the areoles grow.
Areoles: White woolly.
Spines; White to brown with dark tips, not exceed a length of 12 mm.
Flowers: All shades of yellow about 2.5 cm in diameter, outer perianth segments often brownish-red.
Fruits:*** 2.5 to 5 cm long, bright pink colour, ripen within a few weeks after the end of flowering.

Bibliography: Major references and further lectures:
1) Ислайя (Islaya) retrieved 19 March 2016 from <http://m.cvetki.org/cvetki_islaya.php> [Russian]

Cultivation and Propagation: It is an extremely xerophytic, summer-growing, species adapted to very dry soils that, like many cacti of the Peruvian deserts, present some problems in cultivation. It is in fact somewhat rot prone if kept in a non ventilated place.
Growth rate: Slow-growing.
Soil: It requires a very fast draining drying open mineral, sandy-gritty cactus composts. Provide a very good drainage.
Exposure: It is suited for sunny-brightly exposure, but can tolerate light shade. However it will do its best only with lots of sun and become stressed with inadequate light which could result in poor growth and unnatural shape. It has a good heat tolerance.
Watering: Water regularly in summer, but do not over-water and keep it completely dry during winter. Mature individuals easily rot and die especially after transplanting so be extremely cautious with watering. Keep dry in winter or when night temperatures remain below 10° C. Water it less than average if in bigger pots.
Fertilization: Feed them once during the growing season with a fertilizer specifically formulated for cactus and succulents (high potash fertilizer with a dilute low nitrogen), including all micro nutrients and trace elements diluted to ½ the strength recommended on the label. They thrive in poor soils and need a limited supplies of fertilizer to avoid the plants developing excess vegetation, which is easily attacked by fungal diseases.
Special need: It is suited for airy exposures. Provide very good ventilation. Nearly all problems occur as a result of overwatering and poor ventilation, especially when weather conditions are dull and cool or very humid. They must have very dry atmosphere.
Hardiness: It likes warmth (recommended minimum winter temperature 5° C), but hardy to at least -5°C (it can probably tolerate freezing temperatures down to -10° C for brief periods) It has a good heat tolerance.
Pests & diseases: These cacti may be attractive to a variety of insects, but plants in good condition should be nearly pest-free, particularly if they are grown in a mineral potting-mix, with good exposure and ventilation. Nonetheless, there are several pests to watch for.
- Red spiders: Red spiders may be effectively rubbed up by misting the plants from above.
- Mealy bugs: Mealy bugs occasionally develop aerial into the new leaves and flowers with disfiguring results, but the worst types develop underground on the roots and are invisible except by their effects.
- Scales, thrips and aphids: These insects are rarely a problem.
- Rot: Rot is only a minor problem if the plants are watered and “aired” correctly. If they are not, fungicides won't help all that much.
Propagation: Usually propagated from seeds (seldom produces offsets) or graft. The seeds can be sown in pots of fine, well-drained sandy soil, any time during the spring when temperatures are warm. Cover the seeds with a fine layer of grit and water from below with a fungicide to prevent damping off. For the 1-2 weeks cover the pots with a sheet of glass/clear perspex to keep the humidity levels high. Remove the glass and replace it with light shade-cloth and mist once or twice a day for the next two weeks after which most seeds should have germinated. From then on mistings can be reduced to every second and then every third day as the little plants grow. The seedlings should not be disturbed until they are well rooted after which they can be planted separately in small pots. Sometimes it is grafted onto a strong grafting stock like Selenicereus sp. to avoid root rot problems as plants grafted on an hardy stock are easy to grow and no special skill is required. Such grafted seedlings can be been successfully cultivated for years. Mature plants imported from the native habitats usually did not take roots and dyes in a few months.