Devil’s claw is a medicinal plant found in south-west Zambia, with tuberous roots that are exported to treat arthritis in Europe. There are concerns about the sustainability of current harvesting practices.
Hell must be full of plants, for there are many that belong to the devil: from devil’s bit to devil’s cotton, his guts, his paintbrush, his thorns…and his claws! Lying in wait on the surface of deep Kalahari sands are spiny, wooden capsules, armed and dangerous enough to grab on to cloven feet and catch a free ride.
These are the fruits of two species of Harpagophytum, a Greek name that can be translated to “grapple-hook plant”, but more commonly known as devil’s claw. The genus belongs to the Pedaliaceae family, of which foxglove (Digitalis) and sesame (Sesamum) are also members. Local names include: Babamu or Damatwa in Toka-Leya and Tonga; Seto, in Silozi; and Sengaparile in Setswana.
The ground-creepers that produce these resilient fruits are invisible for much of the year, their tuberous roots sustaining them through the dry season and periods of drought. The creeping stems emerge, after the first rains, from a primary tuber known as the “mother tuber”, which can have a tap root up to 2 metres deep. Fleshy roots radiate out out of the mother tuber and form secondary tubers along their length.
Not only do the tubers provide sustenance for the plants themselves, they also contain medicinal compounds that are anti-inflammatory and analgesic, and have been pharmacologically proven as a treatment for arthritis, among other ailments. Because of their effectiveness, hundreds of tonnes of sliced and dried tubers are exported annually, mostly from Namibia, to alleviate the aches and pains of the aging population in Europe.
This trade has been going on for at least 40 years, and there are now serious concerns about over-exploitation and detrimental harvesting techniques. Most of the demand has been for Harpagophytum procumbens, which is found across southern Africa, but now attention is shifting to H. zeyheri, which is the species found in south-west Zambia and northern Namibia.
The trade in devil’s claw in Namibia is controlled by legislation, with permits being required for harvesting, trading and exporting the tubers. In Zambia, however, no such protection is given. The rising demand in Europe, coupled with the decline in the devil’s claw population in Namibia, has pushed the traders across the border into Sesheke District. Here, they hire trucks to collect sacks of tubers, month after month, from the local harvesters, who are digging up even the mother tubers.
There is an urgent need to address this issue, before it’s too late. As one 83-year-old community leader in Sesheke District related: 'My grandchildren laugh in disbelief when I tell them that, when I was a boy, I watched zebra and buffalo roaming freely near our village. It’s too late for the animals, but we must now protect the plants so that they are more than just a tale from long ago.'
More articles in this series:
Rainforest Riches (ZT, Issue 13, June 2013)
Berry banquet (ZT, Issue 12, March 2013)
Marvellous Mangoes (ZT, Issue 11, December 2012)
Underground Forests (ZT, Issue 10, September 2012)
The healing powers of Aloes (ZT, Issue 09, June 2012)
Dogbane Drugs (ZT, Issue 08, March 2012)
Devil’s Claw (ZT, Issue 07, December 2011)
Elephant Toothpicks (ZT, Issue 06, Sept 2011)