New plant species discovered at Tokai Park

A plant species, which has only been collected six times before, has been discovered at Tokai Park.

The species is known as sedge or the hidden veldrush and is listed as critically endangered with extinction.

The plant’s scientific name is Schoenus inconspicuus.

Published in April this year in Phytotaxa, a peer-reviewed scientific journal, the hidden veldrush has been described by UCT botanists Dr Tammy Elliott, Doug Euston-Brown and Professor Muthama Muasya.

According to a statement from UCT, the hidden veldrush closely resembles a grass with which it often grows – Tenaxia stricta, the Cape wire grass.

Telling them apart requires a very careful look at the ligules (which grass experts would know as the flange on the leaf blade where it curls around the stem, and
sedges have a simple sheath instead of a ligule).

Both are rounded tussocks (bunch grasses) with droopy needle-like leaves, although the hidden veldrush is darker green in winter, fading to brown in summer.

The hidden veldrush has only been collected six times. The earliest specimen known was collected by William Purcell in 1919 in the small Koekemakranka Camp on Bergvliet Farm. This locality is now the suburb of Bergvliet.

In 1938 Margaret Levyns, the first woman to get a Doctor of Science degree from UCT and author of the Guide to the Flora of the Cape Peninsula in 1929, collected it on Rooihoogte at Cape Point, but no plants have been found there recently, despite extensive searches.

More recently – in 2012 – plants have been found at Groot Hagelkraal (near Gansbaai), but only as isolated specimens, and collected three times by Dr Elliot and Professor Muasya in their surveys of sedges throughout the Cape region. The sixth record is from Tokai Park.

The occurrence of the plants at
Tokai Park was first officially noticed by Mr Euston-Brown in November last
year.

He states, “I found one plant on November 12 during a species survey, and took a sample to Tammy. She had previously discussed this possibly new species with Muthama and were trying to come to a resolution, and found this specimen interesting. Tammy and I returned the following weekend and collected type material. We only found three individuals after searching around Tokai Park for half an hour.”

This population was chosen as the type locality for the description of the new species. However, inspection of records from iNaturalist revealed that the population was recorded in June 2019 during the Friends of Tokai Park volunteer vegetation surveys, allowing these observations to be correctly named (they were identified only to family level during the surveys).

These surveys are organised annually to document which species have returned to Tokai after the clearance of the alien pine plantations, and to track recovery and map the rare and threatened species at Tokai.

Results of these surveys can be seen at https://www.inaturalist.org/projects/tokai-park-restoration-study and have documented over 10 500 observations by 77 volunteers of 665 plant species at lower Tokai Park.

Many of these are rare and endangered species, emphasising Tokai Park as one of the hottest hot spots on Earth for conserving threatened biodiversity.

From these surveys one has a good idea of the distribution of the various animal and plant species at Tokai Park.

Only the one very small population – a handful of plants – has emerged to date at Tokai Park which suggests that the hidden veldrush is dangerously close to extinction. As more old plantation blocks are restored to fynbos, Alanna Rebelo, from Friends of Tokai Park, says that there is hope that a few more plants may emerge as the critically endangered Cape Flats sand fynbos recovers.

South African National Parks and the South African National Biodiversity Institute-Kirstenbosch are developing a back-up plan to propagate plants, should some unforeseen disaster befall this last population within Cape Town.

Unlike its close relatives, which like wetlands or mountains, the hidden veldrush prefers deep, dry sands, and large areas at Tokai Park which could be suitable for its recovery. Its association with the Cape wire grass suggests which areas at Tokai Park are likely for its re-establishment.

Dr Rebelo says that as with other threatened species, the hidden veldrush’s future is complicated. It appears that this species especially needs fire: but it is uncertain if it coppices to survive fire, or – as it appears likely – is killed by fire and has to establish from seeds: an unusual trait among veldrushes.

Nicky Schmidt, Parkscape chairwoman, says the discovery of a new species and the ongoing attempts to conserve what may remain of old seed banks (subject for over 300 years to human interference from farming to plantations) points to the sheer uniqueness of Lower Tokai.

“On the one hand we have an area of critical conservation value, and on the other we have a section of fundamental human value given the thousands of visitors streaming to Tokai Forest each weekend.

“It points to the need – and an exciting opportunity, as recognised by the Parkscape vision for Lower Tokai – to create a space which can cater for both biodiversity and an urban population.”

Friends of Tokai Park will again be undertaking surveys this spring (if the Covid-19 restrictions allow). If you would like to participate, follow them on Facebook at https://www.facebook.com/FriendsOfTokaiPark and their website https://tokaipark.com/.

Friends of Tokai Park is a community organisation that is made up entirely by volunteers supporting efforts to restore the Cape Flats sand fynbos.