Accepted Scientific Name: Eriosyce islayensis (C.F.Först.) Katt.
Eriosyce (Cactac.) gen. revis. & ampl. (Succ. Pl. Res., 1) 117 (1994)
Islaya krainziana Photo by: Valentino Vallicelli
Origin and Habitat: Eriosyce islayensisSN|1713]]SN|1713]] (Sensu lato) is endemic to the northern Chile along the coast, to southern Peru (just south of Lima). The "krainziana" is the only Chilean population of "Islaya", located around Poconchile above Arica, very near the Peruvian border.
Habitat: It grows in a rainless desert, where only wet coastal fogs served to moisten the loose sand and dust superficially. The roots of these cacti are located immediately below the soil surface surface. Soil is usually without humus and gravel.
Synonyms:
See all synonyms of Eriosyce islayensis
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Accepted name in llifle Database:Eriosyce islayensis (C.F.Först.) Katt.Eriosyce (Cactac.) gen. revis. & ampl. (Succ. Pl. Res., 1) 117 (1994)Synonymy: 52
Cultivars
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Description: Eriosyce islayensisSN|1713]]SN|1713]], formerly known as Islaya islayensisSN|14252]]SN|1716]], is a globose to cylindrical cactus with very woolly areoles and dark spreading spines, it 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 krainzianaSN|14252]]SN|14252]] has stronger somewhat columnar stems that can reach 75 cm high, and this size is rare in the genus Islaya. However Islaya krainzianaSN|1716]]SN|14252]] is generally included within (as a synonym of) Eriosyce islayensisSN|1713]]SN|1713]], suggesting that there is not really a fundamental difference between the two.
Stems: Cylindrical, dark grey-green, erect, 40-75 cm tall later prostrate, about 12 cm in diameter.
Ribs: 19 to 25 low and obtuse.
Areoles: Approximate, very woolly, with creamy-white to grey wool.
Roots: Fibrous.
Spines: Thick, dark reddish-brown to yellow in the centre changing to grey with age, but shading to grey-black towards their tips.
Central spines: 2 to 7 spreading, thick, 12-16 mm long.
Radial spines: 12 to 18, shorter, radiating, (1-)6-10 mm long.
Flowers: Diurnal, about 3 cm long and in diameter, born on younger areoles from a yellowish woolly crown in summer, wide funnelform, yellow, outer perianth segments often reddish, floral tube short with tufts of dense wool and long reddish bristles.
Fruits: Characteristic, up to 5 cm long, club shaped, balloon-like, pinkish to red, openings at maturity by basal pores. Pericarp initially fleshy but the interior always dry when mature.
Seeds: Broadly oval.
Subspecies, varieties, forms and cultivars of plants belonging to the Eriosyce islayensis group
- Eriosyce islayensis (C.F.Först.) Katt.: has globose to cylindrical stems with very woolly areoles and dark spreading spines, the different wild populations constitute a single but multiform species. Distribution: Northern Chile along the coast, to southern Peru (just south of Lima)
- Eriosyce islayensis subs. grandis (Rauh & Backeb.) G.J.Charles
- Eriosyce islayensis subs. omasensis (Ostolaza & Mischler) G.J.Charles
- Eriosyce islayensis cv. TAIWAN: has flat proliferanting stems with large very wooly areoles and short, thin spines. The flowers are pink. Garden origin (Hybrid?)
- Islaya brevicylindrica Rauh & Backeb.: has short cylindrical stems. Distribution: Rio Ocoña to Camana, Southern Coast of Arequipa, Peru.
- Islaya copiapoides Rauh & Backeb.: has few stout spines. Distribution: Rio Ocoña to Camana, Southern Coast of Arequipa in the middle of Islaya territory, Peru.
- Islaya copiapoides var. chalaensis F.Ritter: Has fewer very strong spines. Distribution: North of Chala, along the coast and inland of Arequipa, Peru in the middle of Islaya territory.
- Islaya divaricatiflora F.Ritter: It has mostly red-violet flowers and shorter spines. Distribution: Camana and adjacent areas, Arequipa, Peru.
- Islaya grandiflorens Rauh & Backeb.: has large flowers (the larger of the Islayas) and white wooly crown. Distribution: Chala to Tacna, Southern Coast of Arequipa, Peru.
- Islaya grandiflorens var. spinosior Rauh & Backeb.: has large yellow flowers and many strong spines. Distribution: Chala, Southern Coast of Arequipa, Peru.
- Islaya krainziana F.Ritter: has strong somewhat columnar stems that can reach 75 cm high (the taller of the islayas). Distribution: It is the only Chilean population of "Islaya", located around Poconchile above Arica, very near the Peruvian border.
- Islaya longicarpa Kníže: has very long fruits. Distribution: along the coast near Atico, Peru.
- Islaya maritima F.Ritter: Distribution: Atico, Peru.
- Islaya paucispina Rauh & Backeb.: is similar to "lindleyi" and "chalaensis" (if not the same) but usually with stronger spines. Distribution: Chala, Peru.
- Islaya solitaria n.n.: has often solitary spherical or cylindrical stems up to 20 cm tall and 10 cm in diameter, lime-blue or grey-green. Distribution: Camana Pampa, Peru.
- Neoporteria lindleyi C.F.Först.: has fewer and shorter spines.
Notes: Eriosyce islayensisSN|1713]]SN|1713]] has a large area of distribution and is a very variable species. The difference between populations is the frequency of the appearance in which these forms do occur. So it is possible that two individuals of two different populations can look very similar and also, that two plants of the same population can look very different. However when you are looking at the whole population, you can see the difference between one population and another.
Bibliography: Major references and further lectures
1) Fred Kattermann "Eriosyce (Cactaceae): The Genus Revised and Amplified" David Hunt, 1994
2) Edward Anderson “The Cactus family” Timber Press, Incorporated, 2001
3) 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
4) David R Hunt; Nigel P Taylor; Graham Charles; International Cactaceae Systematics Group. "The New Cactus Lexicon" dh books, 2006
5) Edgar Lamb, Brian Lamb “The Illustrated Reference on Cacti & Other Succulents” Volume 5 Blandford Press, 1978
6) Jan ?íha “Illustrated Encyclopedia of Cacti and Other Succulents” Book Sales, Incorporated, 01/set/1993
7) Curt Backeberg “Die Cactaceae: Handbuch der Kakteenkunde.” 2. ed.. Volume 2, Gustav Fischer Verlag, Stuttgart New York 1983
8) Dillon, M.O. "Lomas Formations - Peru" pp. 519-527. In: S. D Davis, V. H. Heywood, O. Herrera-McBryde, J. Villa-Lobos and A. C. Hamilton (eds.), Centres of Plant Diversity, A Guide and Strategy for their Conservation. WWF, Information Press, Oxford, U.K. 1997
9) Walther Haage “Kakteen von A bis Z” 3. ed. Quelle & Meyer Verlag, Heidelberg 1986
10) N. L. Britton, J. N. Rose: “The Cactaceae. Descriptions and Illustrations of Plants of the Cactus Family.” Volume III, The Carnegie Institution of Washington, Washington 1922
11) E Haustein “Der Kosmos Kakteenfuehrer (the Kosmos Cactus Guide)” United States, Balogh Scientific Books 01/Dec/1998
12) Dr Michael O. Dillon “Lomas formations, Peru” (Field Museum of Natural History, Center for Evolutionary and Environmental Biology, Department of Botany, Chicago, IL 60605- 2496, U.S.A.). http://botany.si.edu/projects/cpd/sa/sa42.htm
Islaya krainziana Photo by: Valentino Vallicelli Islaya krainziana Photo by: Peiffer Clement Islaya krainziana Photo by: Valentino Vallicelli Islaya krainziana Photo by: Valentino Vallicelli Islaya krainziana Photo by: Valentino Vallicelli Islaya krainziana Photo by: Cactus Art Islaya krainziana Photo by: Cactus Art Send a photo of this plant.The gallery now contains thousands of pictures, however it is possible to do even more. We are, of course, seeking photos of species not yet shown in the gallery but not only that, we are also looking for better pictures than those already present.
Read More... 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.