SUCCULENT WONDERS
OF THE KNERSVLAKTE

By Gavin Maneveldt

The Knersvlakte is home to a unique mosaic of
succulent plants dominated by various species of the
Mesembryanthemaceae or vygie family, some of which
mimic their surroundings to a remarkable extent.

 


On many an occasion, while travelling up the west coast, I've stared in amazement at the seemingly barren landscape which hugs the national road to Spingbok. Were it not for my travel companion and friend, a hardy marine biologist from Canada and keen observer who has regularly travelled this way, I might never have come to know the beauty of this landscape. Between Vanrhynsdorp and Bitterfontein lies a stretch of veld which while appearing grey and almost lifeless for most of the year, harbours a unique mosaic of succulent plants which would astound any visitor who was curious enough to stop, look closely, and stare.
This is the Knersvlakte, a landscape typified by small rolling hills with isolated patches of white quartz pebbles, and very saline soils. The red sandy plains found in this area hide, among the quartz pebbles, a floral marvel of nature: a low vegetation (5 - 50cm high) dominated by various species of the Mesembryanthemaceae(vygie or mesemb family).

The beauty and strangeness of the shapes of the Mesembryanthemaceae have long aroused the interest of the amateur as well as that of the professional botanist. One of their most fascinating and appealing aspects is their cryptic behaviour. On my first opportunity to visit the Knersvlakte, I tried to pick up from the stony ground what seemed to be a curiously shaped pebble - a pebble that was firmly rooted and which proved to be a plant. Some of these plants mimic their surroundings to a remarkable extent, like the Argyroderma species with their silver-white to grey-green leaves making them hard to spot among the white quartz pebbles. Similarly, the sheathed bodies of Conophytum uviforme match the white quartzite.


The grey-green leaves of Argyroderma make them hard to spot among the white quartz pebbles.



At a glance, the sheathed bodies of Conophytum uviforme make them invisible against their white quartz backgrounds.


Some species of Conophytum bury themselves alive under a translucent quartzite 'ceiling'.
Many species of Conophytum become literally invisible by burying themselves alive under a translucent quartzite 'ceiling'. Others escape notice simply by virtue of their small size.

It is however only in winter, between the months of April and August, that most of these vygies are visible. Being winter rainfall plants, they tend to disappear completely during the summer months by shrinking underground.


The fine quartz stones have been removed to reveal the plants beneath. The plants in the bottom left of the photo are sheathed.
This apparent survival strategy, results in an astounding phenomenon in the ecology of the mesembs. The conophytums in particular, during their period of rest in the dry season, are even less noticeable because they are then entirely enveloped in a self-created sheath (the parchment-like, whitish or brownish remains of the old pair of leaves). This I have seen particularly well displayed in C. flavum, C. minutum, C. subfenestratum, C. calculus, C. uviforme and C. bilobum. At a first glance, the plant appears to be just the dead, dried-up remains of an earlier generation. Looks can however be deceiving, for beneath these deceptively dead remains lies living tissue, just awaiting the onset of the winter rains.

As the first showers arrive, usually early in April, the sheaths start to crack under the pressure of the living tissue swelling underneath. This is but the least of the amazing feats still to come. As the cracking sheaths start to reveal their summer-secrets, they unveil the miracles which these plants have been hiding so well. Underneath all this seemingly dead tissue, these plants have secretly been regenerating new tissue. Each earlier generation leaf, after sheathing itself the previous year, had hidden the production of not one, but two brand new immaculate leaves. On one occasion I even had the rare opportunity of finding an individual of C. wettsteinii which had produced four new leaves within each of its two protective sheaths.


This fleshy mesem has started to emerge from its protective sheath.

 


This species of Conophytum wettsteinii has produced four new leaves within each of its two protective sheaths.

While many vygie genera occur, few are as well represented on the quartz hills of the Knersvlakte as Argyroderma and Conophytum. Its been a while since I've travelled up the west coast and stopped over at the Knersvlakte, a routine stop on my earlier trips to Port Nolloth, but the memory of it, particular one place where in August the entire hillside seems to be painted pink with Conophytum uviforme in flower, has continued to thrill me.


A species of Argyroderma in flower.

A species of Conophytum in flower.

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