Month: January 2024

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Weird Plants in a Magical Desert

The Richtersveld is a biodiverse, arid area in the Northern Cape Province of South Africa. In 2005, we camped in the National Park for several nights. A 4WD vehicle is essential. We would not have gained entry without it, as the approach road was a sea of mud following recent unseasonal rainfall. We passed a grader ineffectually working to extract a truck that had gone off the road and was stuck in the stuff. Later that day, I recall driving over uneven rock pavement at a steepish gradient, making that first day alone justify the expense of our capable rental. The vehicle had both good clearance and traction.

The attraction of the area for me was the possibility of finding unusual succulent plants. I grow lithops (stone plants) at home, and hoped to find some in their native habitat. Although we did not find lithops here, elsewhere in South Africa, nor in Namibia, which encompasses their native range, we saw a lot of different succulent plants, including other mesembryanthemums, in the Richtersveld. We were also lucky enough to see some in flower.

Species of Conophytum, a genus closely related to Lithops.

The scenery is magnificent. While we were visiting the park we saw few other people. There were a couple of groups camped at the De Hoop campground on the Orange River, but we had Kokerboomkloof to ourselves.

Orange River
Camp by the Orange River
Kokerboomkloof

The kokerboom tree for which the kloof is named, is beautifully adapted to its desert habitat. Known also as the quiver tree, Aloidendron dichotomum is a succulent. It grows well in sandy and rocky soil, storing water in its thick trunk and leathery foliage.

Facilities in the campgrounds were basic. Kokerboomkloof had not water but clean rest room facilities that were tastefully designed to fit in with the environment.

The roads are 4WD tracks, but easily negotiable in dry conditions. The area feels remote and even hostile, although it supports a diverse range of plants and small animals.

This buprestid beetle (they are known as jewel beetles) is a wood borer in its larval stage. We did not see a lot of animal life. Many of the creatures of the desert are nocturnal, allowing them to avoid the desiccating heat of the scorching midday sun. In many protected areas of South Africa driving at night is not permitted. I think this may have been true in the Richtersveld. In any case, we restricted our activities to daylight hours.

Pachypodium namaquanum, halfmens or elephant’s trunk.
A species of Euphorbia.

The succulent plants were spectacular. Many of them, including Pachypodium namaquanum, are slow growing, so we felt as if we were in an ancient forest.

The diversity was very high for such a harsh environment. I had already been amazed at the immense variety of plants in the Cape Region, which is classed as a biodiversity hotspot. The survival of so many species in a small area relies on a complex web on plant-animal interactions, including specialist pollinators and parasites.

Crassula sericea
Codon royenii
Conophytum species.
Mesembryanthemum.
Avonia species.
Mesembryanthemums.
Mesembryanthemum.
Aloidendron ramosissimum.

The scenery was out of this world. I am always attracted to exposed rock that reveals the bones of the landscape. To me, a desert landscape offers both raw beauty of landform and interesting plants that inspire awe for their tenacity in the face of the harshest of conditions. A single flower on one of these plants may be the culmination of years of mere survival.

As individuals we are insignificant in the world. As a species were are devastatingly influential. Hopefully areas such as the Richtersveld will be preserved for future generations to appreciate.

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Climbing Plants

 It requires a lot of energy to grow a rigid trunk that will allow a plant to outcompete its neighbours and capture the light it desperately needs to survive. The clever strategy adopted by climbing plants is to use these neighbours for support. Or maybe, as for this pretty, probably introduced member of the Convolvulaceae (Ipomoea indica) the climber gets a leg up using a human-built structure like this fence.

 The Norfolk Island pine, with its straight, strong trunk, provides an effective ladder for I. indica. Solomon’s sinew, or wild wisteria (Callerya australis) is a native climber that also uses the Norfolk Island pine for support. The photograph below was taken in the Botanic Gardens. The prolific foliage of the climber gathers all the energy it needs to develop thick, strong vines to maintain a structure supported by the host trees.

 Walking beneath the canopy, the vigour of Solomon’s sinew and other climbing plants is apparent from the thick vines that have developed through capturing the sun’s energy from high in the canopy of their host tree. When eventually the host tree dies and falls over, the vine sends out creeping stems to find another tree.

I wondered why these tangles of vines seem to be more common in tropical forests. Probably there are multiple factors. The trees grow faster than in temperate areas, so there is more incentive for other plants to use their structures to gain access to their height. The canopy is often dense, so understory plants have little access to sunlight essential for photosynthesis. Early accounts of the exploration of Norfolk Island tell of it being covered by impenetrable, thick forest.

I have enjoyed spending sufficient time here to explore beneath the surface. Having inadvertently left my colour camera at home, my focus has shifted from bird photography to examining the forest more closely. It is hard to imagine how Norfolk Island appeared to the first Europeans to discover it, Captain James Cook and his crew in 1774. Earlier Polynesian visitors had barely ventured inland from Emily Bay, so left the interior mostly untouched. European and Pitcairn Island settlers cleared much of the land, including felling all the largest trees, so that exotic species could be planted and farmland established. Introduced weeds thrived in the newly created environment. Nevertheless, the National Park (which includes the older Botanic Garden) was set up in 1984 to preserve and restore the original habitat. It provides an experience that will increasingly resemble the original forest as it might have been prior to settlement.