THE LAST REFUGE? by Brian Milligan

It seems that plant life in general and native orchids in particular are under threat everywhere. Vast areas of forest in Brazil and other South American countries are being destroyed by fire every year and a few years ago virgin forest in several Asian countries was burnt by fires that got out of control during illegal burning-off operations. Of course, Australia is not blameless in this regard. Logging operations threaten not only our native orchids but also many other plants, birds and animals, the latest insult being a proposal to reduce the protected zone adjacent to some of our state’s rivers from 200m to 100m.

Recently I’ve been re-reading Orchid Hunting in the Lost World (and Elsewhere in Venezuela) by G.K.C. and E. Dunsterville. This fascinating book reproduces some of ‘Stalky’ Dunsterville’s sixty articles that appeared in the Bulletin of the American Orchid Society over a period of 27 years between 1959 and 1986. During that time the Dunstervilles lived in Caracas ( Venezuela), where ‘Stalky’ was a senior executive with the Shell Company. They stayed on after he retired and lived in a house built amid a hectare of cloud forest on a mountain overlooking Caracas. All their free time was spent hunting orchids throughout Venezuela, often in almost inaccessible areas; they identified over 1050 different orchid species, some of them new to science.

Some of the most interesting of their expeditions were those involving the mesas, known as tepuis in Venezuela. Some of these rocky outcrops rise to an altitude of 2500 m, standing like islands high above the surrounding forest. The largest mesa is Auyán-tepui, which covers an area of almost 800 Km². It is completely surrounded by sheer cliffs and is accessible only at one point, involving the ascent of a 215 m cliff and many lesser ones to an ultimate altitude of 2150 m. The Dunstervilles made the daunting climb to the plateau twice. They found that great expanses of the rocky plateau were devoid of trees and that much of the extensive orchid life was therefore terrestrial or lithophytic. ‘Stalky’ wrote of their second expedition in part as follows:

“Despite the tough exposed conditions in many places – high winds, smashing rains, hot sun and cold nights – the terrestrial orchid life is amazingly prolific. Except where it thins out in truly boggy stretches, it grows so fruitfully anywhere there is soil (and even at times where there is not) that it is almost impossible to avoid treading on orchids at every step. Shut your eyes and walk ten paces, and if you don’t crack your skull against a boulder or break your neck falling into a chasm you will probably have trodden on at least five plants. By simple mathematics, and assuming the route traveled to be roughly representative of the whole, it is no exaggerated guesstimate that of the six major large-plant (orchid) species alone, Auyán-tepui harbors some 50 million plants.

“The undoubted King of the Castle is Eriopsis biloba, highly variable in form of leaf and pseudo-bulb but relatively constant in its two- to four-foot erect inflorescences. The Queen is probably Oncidium nigratum, with large clumps of big pseudo-bulbs and six-foot branched inflorescences. Princes are Epidendrum nocturnum, with flowers up to six inches in spread; Oncidium warmingii with enchanting sprays of delicate white-and-yellow flowers; Zygopetalum burkei with sometimes very light and sometimes very dark flowers; and a large and beautiful new species of Sobralia that has yet to be ‘published’.”

Subsequently the Dunstervilles made trips to several other even less accessible tepuis, thanks to the generosity of the Venezuelan government in providing army helicopters. Most were rich orchid habitats. And hopefully will always remain so – one would imagine that there can be few areas where orchids grow that are less accessible than the tepuis of Venezuela.