HURTLING TOWARDS EXTINCTIONFive charismatic, threatened Red Data List plants.

by Janice Golding, SABONET, c/o National Botanical Institute, Pretoria

Plant Red Data Lists list extinct, threatened and potentially threatened plants that have been assigned risk categoriesaccording to guidelines set by the World Conservation Union (IUCN). Approximately 10% of South Africa's plantspecies appear on the Red Data List (RDL). Preliminary expectations are that many species categorized as 'indeter­minate' or 'uncertain' should in fact be removed from the forthcoming Red Data List. In this article, five plant specieswith RDL status are selected, all of which are found in habitats that are subjected to human modification. Thesecharismatic plants can serve as important flagships for conserving ecologically sensitive habitats. No reference ismade to grasslands and important plant groups (such as cycads or ground succulents) that also desperately requireprotection against extinction.

APONOGETON RANUNCULIFLORUS

Aponogeton ranunculiflorus (Aponogetonaceae) is anaquatic vascular plant, known from humic tarns(sandstone depressions filled with water) from theDrakensberg summit. The species grows at an altitude of2 600 m in the mist belt. The species straddles Lesothoand KwaZulu-Natal. Its RDL status was assessed byHilton-Taylor as 'rare' and as 'vulnerable' by Scott-Shaw(based on past population declines, its limited distrib­ution range and the few number of known localities).

The type specimen was collected in Lesotho'sSehlabathebe National Park, in a 3 ha zone and was firstdescribed in 1972. Subsequent surveys have found morelocalities, all of which are within a 10 kIn radius of thetype locality. Additional localities occur in theuKhahlamba Drakensberg Park and near Sani Pass.The degradation of fens and bogs in Lesotho fromovergrazing and erosion, has resulted in disturbances toits surrounding habitat. The species needs clear poolsbecause siltation disrupts photosynthesis.

The species can readily be cultivated, and seed has

EUPHORBIA PERANGUSTA

Euphorbia perangusta (Euphorbiaceae) is restricted tothe Northwest Province. It has been observed in theGroot Marico area in bushveld on low quartzitic ridgesand amongst rocks. Its RDL status was categorized as'endangered' by both the Traansvaal Threatened PlantsProgramme (then under the Transvaal Department ofNature Conservation) and Hilton-Taylor. Essentially, thespecies is known from one large sub-populationconsisting of fewer than 100 mature individuals, andthree to four sub-populations each consisting of notmore than fifteen individuals. Much of the Groot Maricoarea is subjected to game and cattle farming.

Ralph Peckover gives an account of E. perangusta inVeld 8- Flora (see 'further reading' below) and mentionsintroducing cultivated E. perangusta seedlings into theknown localities. Apparently E. perangusta growsreadily in cultivation. More than 700 seedlings wereproduced from twenty seeds from the late 1980s to themid 1990s. Survival success of the introduced stock hasbeen estimated at around 60%. Well-planned transloca­tions can certainly help to boost species numbers in thewild and can thus save populations from extinction.

Dr Robert Archer from the National Herbarium inPretoria recognizes that E. perangusta is taxonomicallyvery close to E. knobelli, and may well be a subspecies

Veld & Flora March 2001

Aponogeton ranunculiflorus grows completely submerged, exceptfor its flowers that seem to float on the surface. Each individualplant does not reach more than 10 cm in length. This photographwas taken in 1967 by the late Amy Jacot Guillarmod, the pioneerof Lesotho's flora.

been sent to Kew, Holland and Grahamstown. Theflowering time for cultivated plants is less than one year.

Euphorbia perangusta in its natural habitat of rocky outcrops.Definitely something worth seeing in the wild. Photo: Ralph Peckover.

or variety. The taxonomy has thus to be resolved andthis has far-reaching implications for clarifying the RDLstatus of E. perangusta. Introductions of cultivatedmaterial into the wild need to be closely monitored tocheck for reductions in the number of wild individuals.

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SERRURlA AEMULA

The following spiderheads (genus Serruria, Proteaceae)are all from the Cape Flats in the Western Cape and arethreatened by expansion of suburbia. Serruria foenicu­lacea was listed as 'endangered' by Hilton-Taylor. Thelast two remaining individuals were translocated to areserve sanctuary. S. foeniculacea has subsequentlybeen found to be a variant of Serruria aemula and hasbeen instated as S. aemula var. foeniculacea. The othervariety of the species, S. aemula var. congesta, isthought to be 'extinct in the wild'. S. aemula is inter­esting for its range of substrate-related ecotypes (likemany other members of the Proteaceae). Populationsgrowing on loamy and shale-derived, clay elements havelarger, more robust leaves and the plants generally havea bushier habit. Hilton-Taylor assessed the RDL status ofS. aemula as 'endangered' because of its narrow distrib­ution range. The largest sub-population (counted beforethe 1990s) consisted of some 200 mature individualsand exists on a Natural Heritage Site under power-lines.Approximately eighty mature individuals were countedon military base land in 1998. A few other scattered,smaller sub-populations exist on the Cape Flats.A surprising find of a sub-population consisting of aboutforty flowering individuals near a frequently burnt areaearmarked for development (along railway tracks in asemi-formal residential area) was discovered in October1998. It is tempting to upgrade its RDL status.

Serruria furcellata, another Cape Flats endemic, isquite likely extinct. It was last observed in the late1980s before the onset of housing development in thenorth-east sector of the Cape Flats. However, it may wellexist in the eastern Cape Flats area. A disjunct

GERRARDANTHUS TOMENTOSUS

Gerrardanthus tomentosus (Cucurbitaceae) is a creeperthat grows in moist, shaded, coastal sub-tropical thicketmargins (scarp forest). The species is known only fromKwaZulu-Natal's Durban Metropolitan Area. Its RDL ;status was assigned as 'rare' by Craig Hilton-Taylor(1996) and 'vulnerable' (because of its narrow distrib­ution and the few number of localities where it exists inthe wild) by Rob Scott-Shaw (1999). The new proposedRDL status of G. tomentosus is 'critically endangered' or'endangered' based, in addition to Scott-Shaw's reasons,on the few numbers of reproductively matureindividuals. The species has been described as theworld's most threatened caudiciform.. It survives in ahighly fragmented area where there is little possibilityof genetic exchange. The rootstock is harvested wholefor muthi be~ause it is mistakenly identified asGerrardantlius macrorhizus.

G. tomentosus is known only from five herbariumcollections over a 125 year period. The type locality isin lnanda, originally collected by Medley-Wood in the1870s. All subsequent collections have also been madein the vicinity of the metropolitan area. One locality issemi-protected with about ten individuals and here thesurvival of the species is extremely uncertain. The lastfemale plant died and the sub-population is functionallyextinct. Furthermore, the locality, which is less than1 ha, is subjected to alien plant infestations and iscriss-crossed with footpaths. The other locality is wellprotected and was only recently re-discovered.

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Approximately forty individuals of Serruria aemula havemanaged to survive along railway tracks in Bontehuwel in theCape. The substrate here appears to be a fine, grey acid sand anda somewhat coarse-textured, white alkaline sand.Photo: Janice Golding.

population consisting of a few scattered individuals ofS. furcellata was located in the Elandskloof Mountainsand this distribution anomaly has yet to be explained.The Elandskloof sub-population may well be analtogether different taxonomic entity.

Gerrardanthus tomentosus grows from a massive rootstock(caudex) which is substantially smaller than that of G.macrorhizus.Photo: Richard Symmonds.

According to Dr Neil Crouch, this new record is 20 kmfrom the other sub-population, and consists of hundredsof individuals (mature and juveniles), many beingfemale! It is almost certain that none of the other threelocalities exist.

G. tomentosus is uncommon in cultivation. TheSilverglen Nursery in Durban has demonstrated that it isan ideal candidate for horticultural propagation (exceptfor root knot nematodes). Seed-set is between two-and-a­half and four years.

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THE SOUTHERN AFRICAN PLANT RED DATA LIST PROJECT

AcknowledgementsThanks to Neil Crouch, Robert Archer, Ralph Peckover, Rene Glen,Ashley Nicholas, Fanie Venter and Tony Rebelo for theircontributions.

Further readingHilton-Taylor, C. 1996. Red Data List of southern African plants.

Strelitzia 4. National Botanical Institute, Pretoria.Hilton-Taylor, C. 1996. Red Data List of southern African plants. 1.

Corrections and additions. Bothalia 26(2), 177-182.Hilton-Taylor, C. 1997. Red Data List of southern African plants. 2.

Corrections and additions. Bothalia 27(2), 195-209.Peckover, R. 1999. Euphorbia perangusta on the brink of

extinction. Can we help? Veld and Flora 85(4), 170-171.Scott-Shaw, R. 1999. Rare and threatened plants of KwaZulu-Natal

and neighbouring regions. KwaZulu-Natal Nature ConservationService. p. 181.

Mondia whitei.

The project is funded through theNETCAB Programme (RegionalNetworking and Capacity BuildingInitiative for Southern Africa) ofthe IUCN's Regional Office ofSouthern Africa (IUCN-ROSA).Co-support from the GlobalEnvironment Facility (GEF) Projectis implemented by the UnitedNations Development Programme(UNDP). The project willculminate in a publication inSeptember 2001. Should you wishto know more about the SouthernAfrican Plant Red Data Listproject, or if you wish to make acontribution to the Red Data List,please contact the SouthernAfrican Plant Red Data ListCoordinator, Ms Janice S. Goldingat SABONET, c/o NationalBotanical Institute, Private BagX101, Pretoria, 0001 or tel (012)804 3200, fax (012) 804 3211,e-mail golding@nbipre.nbi.ac.za.

The Southern African BotanicalDiversity Network (SABONET) haslaunched the Southern AfricanPlant Red Data List Project. Themain objective of the project is tocompile the southern Africanregion's first comprehensiveaccount of its threatened plantbiodiversity. The countriesinvolved are Angola, Botswana,Lesotho, Malawi, Mozambique,Namibia, South Africa, Swaziland,Zambia and Zimbabwe. Secondaryobjectives are to establish aregional network of persons awareof threatened plants throughoutthe region, and to develop compe­tence in making an inventory ofthreatened floras. South Africa'sNational Botanical Institute isresponsible for the overallmanagement of SABONET. JanineVictor, from the NationalHerbarium in Pretoria, is managingSouth Africa's Red Data List.

Mondia whitei [Apocynaceae(Periplocoideae)] is commonly calledWhite's ginger or uMondi. It is arobust, woody climber that grows in(coastal) swamp forest and alsoriverine forest. It is distributed in theeastern part of southern Africa andoccurs as far north into south-centraland east Africa, and is at its south­ernmost distribution limit inKwaZulu-Natal. It is used widely asa love potion and vanilla substitutein South Africa, Swaziland andMozambique, and occasionally forhorticultural purposes. The assignedRDL status by Hilton-Taylor was'vulnerable' in KwaZulu-Natal and'indeterminate' in the formerTransvaal. Scott-Shaw categorizes thespecies as 'lower risk-conservationdependent'. The current statusshould probably be upgraded to athreat category ('critically endan-gered', 'endangered' or 'vulnerable') due to pastpopulation declines and projected future declines.

Herbarium records from as early as the 1860s remarkan the abundance of the species in KwaZulu-Natal.However, it was predicted in as early as 1915 that thisspecies would become extinct in South Africa becauseof extremely high levels of exploitation as a muthi plant(despite the fact that its stem is difficult to identify indense forests!). Today, the species remains over­exploited across most of its range. Its habitat issubjected to woodcutting, expansion of agriculturalsystems and the draining of wetlands. In KwaZulu-Natalit is known only from isolated pockets each consistingof fewer than twenty individuals in formally protectedareas, and has rarely been observed beyond the bound­aries of protected areas. It is claimedto be near to extinction in the areassouth of the Tugela River. Two verysmall sub-populations are alsoknown from Tzaneen and Duiwels­kloof in Mpumalanga, near a thrivingsub-population of Polystachyaalbescens and Mpumalanga's onlyknown locality of the ground orchid,Calanthe sylvatica respectively.

M. whitei plants produce eithercream or maroon coloured flowers(based on various ecological factors)with maroon the more common, andefforts to determine whether thisrepresents subspecific taxa areunderway.

M. whitei is easily propagatedfrom cuttings, grows well in culti­vation and flowers in less than oneyear. Seed-set in the wild is prolific.It also does well in the Durban andPietermaritzburg Botanical Gardens.In recent years, it has rarely beenobserved on muthi markets, and thisis clearly an indication of the diffi­culty in finding plants in the wild.Many more localities and sub­populations probably exist, and theseneed to be recorded and monitoredby conservation authorities. ®

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