“He wrote that he was so astonished that he knelt on the hot sand in bewilderment, thinking that his fantasies had taken flight.”Chris Bornman, describing the reaction of Friedrich Welwitsch upon seeing Welwitschia mirabilis for the first time.
A fine candidate for the most world’s most biologically unique plant, Welwitschia mirabilis is the sole member of the family Welwitschiaceae. This strange cone-bearing plant was first brought to the attention of science by the plant explorer for whom it was named.
Friedrich Welwitsch was an Austrian, trained in medicine and botany, who disappointed his parents by not developing a law career. Instead, after briefly working as a physician, he pursued his interests in plants, working for important botanical gardens in Portugal and England. His African explorations resulted in the discovery of several new species. Welwitsch died in 1872 but left a fine collection of many thousands of dried herbarium specimens. Three hundred and twenty nine species of plants and animals have been named in his honor.Male and female plants bear cones on short branches; the winged seeds need a bit of surface soil moisture to germinate. Consequently, the reproductive success rate is low. Outlandish claims are often made concerning Welwtschia’s longevity. More accurately, by measuring the growth rates of their leaves, it’s estimated that individual plants can live 500 to 1000 years.
Welwitschia is related to other cone-bearing plants, such as
cycads and the relic family of trees and vines, the Gnetaceae. From evidence in
the fossil record, the ancestors of Welwitschia diverged from other conifers at
least 114 million years ago. The ancestral Welwitchias' forest habitat dried and vanished; the modern species seems like a fanciful creation from the imagination of Dr.
Seuss. Welwitschia mirabilis is a
woody, two-leaved dwarf “tree” that ekes out it existence in parts of the Namib
Desert of Angola and Namibia in areas that can receive no rain at all for several
consecutive years. As in western South America, the plant communities of the coastal
Namib Desert have evolved to rely upon the nightly fogs that are generated by
cold ocean currents. Welwitschia’s metabolism requires some foggy humidity to
function, but the species ultimately survives by tapping into deeper soil moisture that is recharged
by infrequent rainfall.
|Namib Desert Fog. Image by Juliane Ziedler|
|Welwitschia seedling. Image by H. Maurer|
|Welwitschia near Swakopmund, Namibia. Image By Joh Henschel|
|Image by Thomas Schoch|