New Species Discovered at Tokai Park
Critically Endangered Hidden Veldrush (Schoenus inconspicuus) described
A new species of Sedge, the Hidden Veldrush (Schoenus inconspicuus), has been described from Tokai Park by Dr Tammy Elliott, Doug Euston-Brown and Professor Muthama Muasya
By Tony Rebelo
Introduction
A new species of Sedge has been described from Tokai Park. The Hidden Veldrush is known from less than 10 plants and is listed as Critically Endangered with extinction. Published in April this year in the journal Phytotaxa, the Hidden Veldrush (Schoenus inconspicuus) has been described by Dr Tammy Elliott, Doug Euston-Brown and Professor Muthama Muasya at UCT.
As its name suggests, Schoenus inconspicuus is not an ostentatious plant. In fact, it closely resembles a grass with which it often grows, Tenaxia stricta, or Cape Wire Grass. Telling the two plants apart requires a very careful look at the ligules, which grass aficionados would know as the flange on the leaf blade where it curls around the stem. Sedges have a simple sheath instead of a ligule.
Hidden Veldrush and Cape Wire Grass are rounded tussocks with droopy needle-like leaves but, in winter, Hidden Veldrush is a darker green and fades to brown in summer. Whereas the Cape Wire Grass is common in the Fynbos biome, the Hidden Veldrush is known from fewer than 10 plants on Earth. The type specimen and almost half the known plants grow in the Tokai Park section of Table Mountain National Park.
Background
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 – famous as the first woman to get a DSc from UCT and author of the Guide to the Flora of the Cape Peninsula in 1929 – collected it on Rooihoogte at Cape Point but, despite extensive searches, no plants have been found there recently.
The Bergvliet and Rooihoogte specimens were initially identified as related species, but were noted as aberrant due to their long, shiny flowerheads.
More recently, in 2012, plants were found only as isolated specimens at Groot Hagelkraal near Gansbaai, and collected three times by Tammy and Muthama 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 officially first noticed by Doug in November last year.
Doug says, “I found one plant on 12 November during a species survey, and took a sample to Tammy. She had previously discussed this possibly new species with Muthama. They 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.”
Early observations
Although this population was chosen as the type locality for the description of the new species, an inspection of iNaturalist records shows the population to have been 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 organized annually to document species that have returned to Tokai Park the clearance of alien pine plantations, as well as to track Tokai Park’s recovery and map its rare and threatened species. Surveys have documented more than 10 500 observations of 665 plant species by 77 volunteers at lower Tokai Park. Many of these are rare and endangered species, emphasizing Tokai Park’s status as one of the hottest hotspots on Earth for conserving threatened biodiversity.
From these surveys we have a very good idea of the distribution of the various animal and plant species at Tokai Park. Only one population of Hidden Veldrush – a handful of plants – has emerged to date. This and one other known small population suggest that the Hidden Veldrush is perilously close to extinction. Presumably, it was once relatively widespread and common in the Bergvliet-Tokai area. We hope that more plants may emerge as Critically Endangered Cape Flats Sand Fynbos recovers following the restoration of old plantation blocks to Fynbos.
SANParks and SANBI-Kirstenbosch are developing a backup plan to propagate plants should some unforeseen disaster befall this last population within Cape Town. However, it is hoped that this species can be saved from extinction. Unlike its close relatives, which like wetlands or mountains, the Hidden Veldrush prefers deep, dry sands and large areas at Tokai Park should be suitable for its recovery. Its association with the Cape Wire Grass suggests which areas at Tokai park are likely for its reestablishment.
Future restoration
As with other threatened species, the Hidden Veldrush’s future is complicated. It appears that this species is highly fire dependent, but we don’t yet know if it coppices to survive fire or, as appears likely, is killed by fire and has to establish from seeds – an unusual trait among Veldrushes.
Its rarity also suggests that this is a species that likes open spaces, such as grazed areas, and might not compete well with coppicing species such as the Cape Wire Grass. However, Veldrushes don’t fare well in heavily grazed areas as they are often eaten.
Studies on the plant’s regeneration ecology will need to wait for the next fire. In the meantime, we will have to plan for its future. Park Management at Tokai needs to restore the ecological processes and individual species need, for the most part, to look after themselves – with just a little help from Kirstenbosch.
Needless to say, we expect more exciting discoveries as the Fynbos at Tokai Park recovers.
Friends of Tokai will again be undertaking vegetation surveys this spring (Covid19 restrictions permitting). If you would like to participate, please keep yourself up to date with our forthcoming events by way of Facebook or our website.
Reading
Elliott T.L, Euston-Brown D.I.W. & A.M. Muasya Schoenus inconspicuus (Cyperaceae, tribe Schoeneae): a new species from Southern Africa Phytotaxa 440 3, 28 April, 2020, pages 239-244
Images
iNaturalist (Creative Commons)
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