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The Welwitschia mirabilis — one truly remarkable plant

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I’ve never been to Namibia and never expected to regret it.

Over the years, however, the plant Welwitschia mirabilis has cropped up in articles and classes as a supremely unique plant.

Imagine my surprise when wandering through the extensive tropical house at the Botanical Garden in Frankfurt, Germany, I saw a huge specimen through the glass walls. I simply stood there in shock, and finally reached for the doorknob, only to find that the room was locked.

Apparently, it is only open to the public for several hours, once a week. And Friday, when we showed up, was not that day.

Acknowledging intense public interest, there is a viewing gallery on the second floor together with a lengthy explanation of the plant’s characteristics written — unfortunately for me — only in German, forcing me to do my research back in the States.

It is somewhat difficult to define the allure of Welwitschia mirabilis. Growing under severe conditions in the Namib Desert — which runs along the Atlantic Ocean in Namibia and north into Angola — it has the rugged appearance of many desert plants.

Considered a dwarf tree or shrub, it has a fibrous stem in the shape of an inverted cone (obconical) which reaches an average height of 20 inches, although there is one living specimen reaching six feet. The inverted cone is the result of the early death of the more-usual growing point at the top of the stem, forcing additional stem growth to go upward and outward.

The twisted mass of strap-shaped leathery leaves are, in reality, only two long leaves which continue growing for the life of the plant. Weathering causes the ends of the leaves to fray, giving the plant a tattered appearance.

The tattering, perhaps, also prevents the leaves from spreading outward, but causes them to twist back toward the stem. Unfurled, they can reach up to 46 feet in length.

Some theorize these leaves shade the soil underneath the plant, slowing water evaporation and protecting the root system, which consists of a taproot and some lateral roots. Insects and animals also find a refuge in this shade.

The leaves have stomata (openings) on both sides (amphistomatic). Generally, stomata regulate gas exchange and allow for the evaporation of water. There is a recurring assumption with Welwitschia that the water droplets that condense onto the leaves from the nightly local fog — the result of a cold Atlantic Ocean current —are absorbed through the upper stomata, but this has not been proven.

However, the water condensate on the leaves does roll down the leaves toward the stem and drips onto the soil where it is absorbed by the taproot.

Welwitschia is dioecious, meaning that there are male and female plants. The specialized branches producing the strobili — the beautiful conical structures containing the ovules and the pollen — grow upright from the stem, near the leaf bases. The salmon-colored cones are males, and the larger blue-green cones are female.

There also is a debate over pollination. Since the plant does not produce the huge amounts of pollen that a wind-pollinated plant would — and several insects are routinely seen on and around the plant — the present assumption is that Welwitschia is pollinated either by the beetle Odontopus sexapunctatus, and/or by bees and wasps.

Another cause of wonderment surrounding our Welwitschia is its extended life span. While the average span seems to be 500 to 600 years, it is believed that some plants are between 1,500 and 2,000 years old. Fossil evidence goes back 113 million years.

“Mirabilis” means “wonderful” in Latin. However, Welwitschia is not a name that just rolls off the tongue. It was chosen to honor the Austrian botanist Friedrich Welwitsch (1806-1872), most of whose work was conducted in Portugal and the Portuguese colony of Angola.

In 1859, he discovered our eponymous plant, which he named Tumboa strobilifera. It was renamed by Joseph Dalton Hooker, the director of the Royal Botanical Garden at Kew.

In 1861, Welwitsch returned to Portugal but then took his collections of thousands of specimens, with Portuguese permission, to the British Museum and Kew Gardens. Unfortunately, after his death, there were lawsuits between the Portuguese and the British as to who would receive the best of the specimen copies.

Our Welwitschia mirabilis is the only member of the family Welwitschiaceae, in the division gnetophyta. In addition to this honor, six genera and 300 species of plants are also named for Friedrich Welwitsch.

To check this out, just look up the welwitschii, which is the epithet of the scientific name.

So, whether you are amazed by its hardiness, lifespan or unique growth patterns, this is a plant well worth knowing!

Have a thought or comment for Sura Jeselsohn? Email her at greenscenesura@gmail.com.

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