Saturday, November 2, 2013

Greenhouse plant in Himalaya (Rheum nobile)

Extreme rhubarb: The plant that grows a greenhouse

THE foothills of the Himalayas are lush and verdant. But the higher you go, the shorter the plants get. Above the treeline, at around 4000 metres above sea level, conditions are extreme. It's cold and windy, the steep slopes consist mostly of shattered rocks rather than soil, and from above comes an invisible barrage of ultraviolet light. The plants here are tiny and cling closely to the mountainsides, barely peeking above the scree-clad slopes. Every now and then, though, a towering pale form looms, ghostlike, out of the mist.
When the botanist Joseph Hooker caught his first glimpse of this peculiar plant in the 1840s, he was "quite at a loss to conceive what it could be". From a base of normal green leaves rises a hollow column made of overlapping pale-yellow leaves. The columns can grow nearly 2 metres high, dwarfing the other vegetation around them.