Islaya
| Islaya | |
|---|---|
| File:Islaya islayensis.jpg | |
| Kingdom | Plantae |
| Family | Cactaceae |
| Subfamily | Cactoideae |
| Tribe | Notocacteae |
| SubTribe | |
| Genus | Islaya |
| Species | |
| Notes | Taxonomy follows Joël Lodé (2015). Lodé maintains Islaya as a distinct genus from Eriosyce. |
Etymology
The genus is named after the province of Islay in the Arequipa region of southern Peru, where the type species was discovered.
Description
Islaya consists of globose to shortly cylindrical cacti, often covered with dense, sturdy spines.
- Stems: Typically solitary, grey-green to dark green, often with a flattened apex covered in wool.
- Flowers: Diurnal and relatively small, appearing at the apex. They are funnel-shaped and almost always bright yellow. The floral tube is short and woolly.
- Fruits: Very characteristic – they are elongated, balloon-like, hollow, and reddish when ripe. They are indehiscent and designed to be easily detached and blown by the wind (anemochory) or moved by water.
- Seeds: Relatively large, black, and matt with a wrinkled testa.
Habitat
The genus is highly specialized for the hyper-arid coastal deserts. They grow on rocky slopes and sandy hills where rainfall is almost zero; they survive by absorbing moisture from the heavy coastal fogs known as "camanchaca." Altitudinal range: 0–1500 m.
Distribution
- Peru: Southern coastal regions (Arequipa, Ica, Moquegua, Tacna).
- Chile: Extreme northern coast (Arica).
Species and Subspecies
Following Lodé (2015), the genus includes 11 species and 2 subspecies:
- Islaya brevicylindrica
- Islaya copiapoides
- Islaya divaricatiflora
- Islaya flavida
- Islaya hualtacoensis
- Islaya islayensis
- Islaya krainziana
- Islaya maritima
- Islaya minuscula
- Islaya omasensis
- Islaya paucispina
Taxonomy
The classification of Islaya is highly debated. Molecular studies show a close relationship with the Chilean Eriosyce, leading many taxonomists to merge them. However, Joël Lodé maintains Islaya as a distinct genus based on its unique fruit morphology (the wind-dispersed "balloon" fruit) and its isolated distribution in the Peruvian coastal desert.
