The legend of the almost-extinct Tokai Cape Flats Silkypuff

By Dr Alanna Rebelo and Dr Tony Rebelo

The Cape Flats Silkypuff (Diastella proteoides) is a low-growing member of the Protea family, forming a sprawling groundcover. It has charming puff-like clusters of small flowers (less than 10 mm in diameter), which are rosettes of pointed pink star-like, hairy bracts.

Once common on the lowlands of the Cape Flats, from Tokai to the northernmost border of the City of Cape Town Metropolitan Municipality near Atlantis, and north to Darling, it is now critically endangered. The southern populations differ from those in the north in being flat growing mats, rather than sprawling plants, and having longer leaves. More than 80% of this species is lost, mainly due to urban expansion.

Its remaining populations are still in decline due to poor management, including inappropriate fire regimes and mowing. Those populations that remain are in dire straits, with the exception of one that survives due to an accident at Tokai Park. This story is about this Tokai Diastella patch.

Above The Cape Flats Silkypuff (Diastella proteoides) form (left) and flower (right) at Tokai Park Photos: Nigel Forshaw

It was in the 1970s that Nigel Forshaw used to cycle from Bergvliet into the Tokai plantation before the M3 highway was completed. While cycling alongside the “Berlin Wall” track -through all that sand- he found a patch of fynbos, a botanical treasure, in a thinned-out patch of Pines. This fynbos survived because this patch of soil received more sunlight than the surrounding plantation.

When Nigel joined the Protea Atlas Project in the 1990s, he remembered his find and set off in July 1994 with two other amateur botanists, Lyn and Deryck McCallum, to check it out. Deryck spotted the Cape Flats Silkypuff and knew it was something interesting.

Previously thought to be extinct on the Cape Flats, they found around 11 Cape Flats Silkypuff plants. The plot being found by him, Nigel atlassed the site for the Protea Atlas Project, and found other treasures, including Leucospermum conocarpodendron ssp viridum, Serruria fasciflora and Serruria glomerata (the Brabejum stellatifolium was missed at the time).

Then, in 1998, a fire burnt through the Diastella patch. The exact circumstances of the fire are sketchy, but legend has it that young people enjoyed building tepees out of pine tree branches. These tepees were allegedly knocked down by people concerned about the fire risk. This upset the builders, and they then started the fire – it is supposed – out of revenge.

Though perhaps unintended by the alleged arsonists, this was exactly what the Cape Flats Silkypuff needed, and they have been thriving ever since. About 20 years later, this area is due for another ecological burn to ensure the survival of this population.

Some other areas have not been as fortunate. According to Nigel, there were other patches of fynbos with some rare Ericas less than 100m away. Sybil Morris first pointed out the Cup Heath (Erica subdivaricata) to the Botanical Society’s A-Team, a hiking group. Unfortunately, this area did not burn and the Ericas have disappeared.

Likewise, before the 2000s, there were several Cape Flats Silkypuff plants outside the main patch, but these have also disappeared. Their survival depends on the next fire.

Much about the Cape Flats Silkypuff is still unknown. We do not know what pollinates it but, given that it does not produce nectar, its pollinator is likely to be a pollen-feeding insect. There is so much to learn about this species, yet it is almost extinct.

As one of the last remaining patches of Cape Flats Sand Fynbos, Tokai Park is a site of critical importance for conserving the last populations of many of our rare lowland fynbos species. However, conserving fynbos in a national park is not possible without the fire needed for different species to survive. Tokai Park therefore needs to be well managed.

Since urbanising the Cape, we humans have created “fire shadows” (altered ignition source points), reducing fire events. According to Dr Jasper Slingsby and others, this has caused a shift to “low‐diversity, non‐flammable forest at the expense of hyperdiverse, flammable Fynbos ecosystems”.

Although much of our fynbos occurs in conservation areas, these ecosystems are collapsing and desperately need management interventions, says Dr Slingsby.

Managers conduct ecological burns because natural fires have been eliminated due to human activity. These prescribed fires both ensure the survival of species and keep the vegetation within safe fuel load margins.

Ecological burns differ from restoration burns. Restoration burns may be necessary to remove the biomass of invasive alien trees and stimulate fynbos seedbanks following clearing. Both types of prescribed burns are important in Table Mountain National Park as they facilitate the difficult transition from plantation forestry to a national park and core conservation area.

What can you do? You can support Friends of Tokai Park’s restoration work and hold SANParks to its conservation mandate. Support SANParks when it conducts ecological burns and help raise awareness about this important management practice by sharing this article.

This remaining population of Cape Flats Silkypuff is not out of the woods yet. It is in dire straits. There are only about 100 plants remaining, and therefore there is not what scientists call a ‘minimum viable population’. A minimum viable population is the lower bound on the number of individuals needed for a species to be able to survive (reproduce) in the wild.

This minimum viable population would typically be about 2500 plants. We need more suitable areas to preserve our critically endangered lowland fynbos species, such as the area that exists where the pines are now.

Below The famous Diastella patch at Tokai Park in 1999 (shortly after the 1998 fire) and in 2005. Photos: Nigel Forshaw