Cloud Forests : Conserving Our Botanical Treasures


San Francisco Botanical Garden's Southeast Asian Cloud Forest
What is a Vireya Rhododendron?

Rhododendron renschianum
   Rhododendron renschianum


The name comes from the French pharmacist and natural historian, Julien Joseph Virey. Vireyas, as they are commonly called, are a taxonomic group of species within the large genus Rhododendron. They are distinguished by their long-tailed seeds and distinctive scales on the leaves. Their thick, waxy-textured flowers are vividly colored, ranging from white, cream, yellow, orange, salmon, pink, deep red, to almost maroon.

Almost all Vireyas originate from Malesia, a botanical Latin term describing the geographic area extending from the Malay Archipelago through the Philippines, Borneo and Indonesia to New Guinea and surrounding islands. Thus, Vireyas have often been called Malesian rhododendrons.

Rhododendron konori
  Rhododendron konori



In nature, Vireyas can be found growing from sea-level to above 8,000 feet, but are most common at the higher elevations. They are often seen growing as epiphytes on other larger plants or trees, using them as support to gain more sunlight, but not harming them directly. Due to this epiphytic tendency, Vireyas in cultivation require an extremely well-drained growing medium. They flower intermittently throughout the year, with a peak in spring. This is due to their tropical origin, where there are no clearly defined seasons.


Rhododendron ericoides
 Rhododendron ericoides



More Vireyas

Rhododendron lochae X R. macgregoriae

Rhododendron helwigii


Over 300 species of Vireya are known, constituting one third of all known rhododendron species. Botanists believe there are still more that are unknown to science, awaiting discovery in some unexplored mountain. Such areas still exist, such as the mountainous interior of New Guinea, and some canyons on Mt. Kinabalu in Borneo.

Learn More about Vireyas



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