Copyright © NISC Pty Ltd South African Journal of Botany 2002, 68: 370–375 Printed in South Africa — All rights reserved SOUTH AFRICAN JOURNAL OF BOTANY ISSN 0254–6299 Threatened plants of Gauteng, South Africa MF Pfab1* and JE Victor2 1 Gauteng Department of Agriculture, Conservation, Environment and Land Affairs, PO Box 8769, Johannesburg 2000, South Africa 2 National Herbarium, National Botanical Institute, Private Bag X101, Pretoria 0001, South Africa * Corresponding author, e-mail: MicheleP@gpg.gov.za Received 20 September 2001, accepted in revised form 19 February 2002 The Red Data List status of threatened plants of Gauteng, South Africa is presented. This includes evaluations using categories and criteria adopted by the IUCN in 1994 and updated in 2000 for assessing the risk of extinction. A total of 23 taxa were found to be threatened, nine are Data Deficient and 33 former Red Data taxa are not threatened with extinction. The major threat to the continuing persistence of threatened plants in Gauteng is urban development. Recommendations for the conservation of these species are made, and suggestions are given for research needs on certain taxa for which inadequate information is available. Introduction Although it is the smallest province of South Africa, Gauteng is an important economic region in terms of business and industrial development, mining and agriculture. In view of the rapid expansion of the urban areas that are encroaching especially on the poorly conserved Highveld grassland, it was decided to investigate and document the conservation status of the plant taxa in Gauteng. The aim of this compilation is primarily to identify those taxa most in need of conservation attention and assist conservationists by providing clear information for action planning and conservation of the threatened species. In addition we hope it will be of assistance to developers and consultants for developments who need clarity on the exact status of the threatened plant taxa in the Gauteng region. In 1996, Hilton-Taylor’s publication of the Red Data List of southern African plants provided the most widely used and comprehensive list of threatened plants and their status to date. Hilton-Taylor (1996) used criteria for assessing conservation status that had been in place for more than 20 years. After many years of wide consultation, the Species Survival Commission (SSC) developed a new objective approach for determining the status of threatened plants (IUCN 2000) which was formally adopted by the International Union for Conservation of Nature (IUCN) Council in 1994 and revised in 2000. The new system differs in that it targets more specifically taxa that are in danger of going extinct rather than those that are simply rare, using quantitative methods of assessment. In 1997 the Gauteng Directorate of Nature Conservation initiated a project to determine the status and distribution of the threatened plant species of Gauteng. The project is specifically designed to partially meet the first objective of the Convention on Biological Diversity, i.e. the conservation of biodiversity, and goal 1 of the White Paper on the Conservation and Sustainable Use of South Africa’s Biological Diversity (Department of Environmental Affairs and Tourism 1997), a document that describes a biodiversity policy and strategy for South Africa. It was decided that a synopsis of the status of threatened plants occurring in Gauteng was a priority primarily due to the high level of activity with regards to urban and industrial development in the province. This is a first attempt to compile a Red Data List for the Gauteng province. Materials and Methods The taxonomic treatment follows herbarium practice at the National Herbarium, Pretoria. In order to establish previously recorded localities, the plant collections at the National Herbarium (PRE), HGWJ Schweicherdt Herbarium (PRU) and CE Moss Herbarium (J) were consulted and additional locality records were obtained from the Precis database. Red List categories are assigned in accordance with the guidelines set by the IUCN-SSC (IUCN 2000). For taxa that are endemic to South Africa, the conservation status assigned will be the same at a national and global level, whereas for those taxa that occur in other countries the conservation status assigned is the national status. Quantitative criteria are used to place a species in a particular Red List category. In most cases, extensive fieldwork was carried out by the Gauteng Directorate of Nature Conservation where locality, ecological and population data were recorded for each subpopulation located after careful searches. Extent of occurrence was calculated for these South African Journal of Botany 2002, 68: 370–375 species using the IDRISI for Windows Geographic Information System package. Where sufficient information was available, data were analysed using RAMAS Red List Version 2.0, a software package developed by a software development company, Applied Biomathematics. This software implements the IUCN Red List criteria for classifying species into one of the three categories of threat, or a category of lower risk, namely Near Threatened (NT) or Least Concern (LC). The three categories of threat are, in order of decreasing risk of extinction, Critically Endangered (CR), Endangered (EN) or Vulnerable (VU). If insufficient data are available to arrive at a conclusion, the taxon is classified as Data Deficient (DD), especially in cases of taxonomic uncertainty. Results In the sections that follow, the accepted scientific name of each plant taxon classified as ‘threatened with extinction’ according to the IUCN categories and criteria (2000) is provided, followed by details on distribution, habitat, threats and conservation status (the old status according to Hilton-Taylor 1996 in parenthesis follows the updated category and criteria according to IUCN 2000). The reader should refer to the IUCN 2000 guidelines for detailed interpretation of criteria, but in general the A criterion indicates a declining population, the B criterion a small distribution and decline or fluctuation, the C criterion a small population size and decline and the D criterion a very small population or restricted distribution with no decline. Taxa for which there was insufficient information to make an assessment are listed in Table 1. Those taxa for which there is some concern, either due to their rarity (based on the rarity concept devised by Kruckeberg and Rabinowitz (1985)) or, in the case of common species, due to an identified causal factor of decline, but did not qualify as ‘threatened with extinction’ are listed in Table 2. Taxa in Table 3 are those that are not ‘threatened with extinction’ or close to qualifying for this status. Taxa are dealt with in alphabetic order. Aloe peglerae Schönland (Asphodelaceae) This distinctive species is found mainly in the Magaliesberg range in Gauteng and North West Province, with outlier pop- 371 ulations near Krugersdorp and on the Witwatersberg. It is found in rocky areas, on northern slopes or at the summit of ridges. It is threatened by urbanisation and illegal collection. This aloe occurs in various Heritage sites and nature reserves, and within the Magaliesberg Protected Natural Environment. Status: EN A2d+3d+4d; B1ab(ii,v)+2ab(ii,v) (previously Rare). Brachystelma discoideum R.A.Dyer (Apocynaceae) Although a widespread species distributed in the northern provinces of South Africa and in Botswana and Zimbabwe, it is extremely rare throughout its range. It is threatened by habitat transformation due to urbanisation and agriculture. A specimen has been collected in an area of Gauteng that is now a provincially managed nature reserve. Status: VU B2ab(ii,iii,iv) (previously Rare). Ceropegia decidua E.A.Bruce subsp. pretoriensis R.A.Dyer (Apocynaceae) This plant is restricted to the Magaliesberg and associated ridges where it grows on quartzitic rocky outcrops, in pockets of soil among rocks. It is threatened by alien vegetation, trampling, habitat fragmentation and transformation through urbanisation. Although it occurs in the Bronberg Nature Area, this area has no formal legislative status and property development is transforming the habitat. It also remains in two municipal nature reserves, however, these reserves are neglected. Status: CR B1ab(ii,iii,iv,v)+2ab(ii,iii,iv,v) (previously Rare). Cineraria longipes S.Moore (Asteraceae) The former distribution range of this plant has been greatly fragmented by urbanisation. It still exists on the Klipriviersberg south of Johannesburg and southwards to approximately 10km south of the Suikerbosrand, on south facing slopes of basaltic koppies. This species is threatened by urban development, habitat fragmentation and transformation, mining and alien vegetation. It occurs in Suikerbosrand Nature Reserve and Klipriviersberg Nature Reserve. Status: EN B1ab(i,ii,iii,iv,v)+2ab(i,ii,iii,iv,v); C1+2a(i) (not listed previously). Table 1: Taxa for which there is insufficient information to make an assessment and therefore listed as Data Deficient (DD). Provinces in South Africa (SA) from which species have been recorded are indicated, including Gauteng (G), North West (NW), Mpumalanga (MP) and Free State (FS). Former conservation status (Hilton-Taylor 1996) is indicated, where former categories include Endangered (E), Vulnerable (V), Rare (R), Indeterminate (I), Insufficiently Known (K), not threatened (nt) and no information (?) Taxon name author Agrostis eriantha Hack. var. planifolia Gooss. & Papendorf Delosperma davyi N.E.Br. Delosperma framesii L.Bolus Delosperma knox-daviesii Lavis Delosperma leendertziae N.E.Br. Dicoma pretoriensis C.A.Sm. Harveya anisodonta C.A.Sm. Lepidium mossii Thell. Lithops lesliei (N.E.Br.) N.E.Br. subsp. lesliei var. rubrobrunnea de Boer Family Endemic to SA National status Province Poaceae Yes DD G Aizoaceae Yes DD G Aizoaceae Yes DD G Aizoaceae Yes DD G Aizoaceae Yes DD G, NW, MP Asteraceae Yes DD G Scrophulariaceae Yes DD G Brassicaceae Yes DD G, FS Aizoaceae Yes DD G Old R Not Not Not K Not Not Not Not status listed listed listed listed listed listed listed 372 Pfab and Victor Table 2: Taxa that do not meet the criteria for being listed as ‘threatened with extinction’ but could qualify in the future, therefore listed as Near Threatened (NT). Provinces in South Africa (SA) from which species have been recorded are indicated, including Gauteng (G), North West (NW), Mpumalanga (MP), Northern Province (NP), Free State (FS), KwaZulu-Natal (KZN), Eastern Cape (EC), Northern Cape (NC) and Western Cape (WC). Former conservation status (Hilton-Taylor 1996) is indicated, where former categories include Endangered (E), Vulnerable (V), Rare (R), Indeterminate (I), Insufficiently Known (K), not threatened (nt) and no information (?) Taxon name author Barleria rehmannii C.B.Clarke Bowiea volubilis Harv. ex Hook.f. Brachiaria subulifolia (Mez) Clayton Calamagrostis epigeios (L.) Roth. var. capensis Stapf Ceropegia turricula E.A.Bruce Encephalartos lanatus Stapf & Burtt Davy Gladiolus robertsoniae F.Bolus Habenaria bicolor Conrath & Kraenzl. Heteranthera callifolia Rchb. ex Kunth Kniphofia typhoides Codd Mosdenia leptostachys (Ficalho & Hiern) Clayton Nuxia glomerulata (C.A.Sm.) I.Verd. Family Endemic to SA National status Province Acanthaceae No NT NP, G, MP Hyacinthaceae No NT KZN, NP, G, MP, EC, FS Poaceae No NT G, MP Poaceae No NT G, EC, WC, NC Apocynaceae Yes NT NP, MP, G Zamiaceae Yes NT MP, G Iridaceae Yes NT MP, G, FS Orchidaceae No NT G, MP Pontederiaceae No NT NP, G, NW Asphodelaceae Yes NT MP, G, NW, KZN, FS Poaceae Yes NT G, MP, NW, NP Buddlejaceae Yes NT NW, G Old status K K nt nt K R R R Not listed K K R Table 3: Taxa previously listed on the Red Data List (Hilton-Taylor 1996) which no longer qualify as ‘threatened with extinction’, and are therefore listed as Least Concern (LC). Provinces in South Africa (SA) from which species have been recorded are indicated, including Gauteng (G), North West (NW), Mpumalanga (MP), Northern Province (NP), Free State (FS), KwaZulu-Natal (KZN), Northern Cape (NC) and Eastern Cape (EC). Former conservation status (Hilton-Taylor 1996) is indicated, where former categories include Endangered (E), Vulnerable (V), Rare (R), Indeterminate (I), Insufficiently Known (K), not threatened (nt) and no information (?) Taxon name author Aristida recta Franch. Asclepias cultriformis Harv. ex Schltr. Asclepias eminens (Harv.) Schltr. Asclepias fallax (Schltr.) Schltr. Ceropegia mafekingensis (N.E.Br.) R.A.Dyer Cynanchum virens D.Dietr. Disperis concinna Schltr. Eragrostis patens Oliv. Eulophia cooperi Rchb.f. Habenaria kraenzliniana Schltr. Harveya pumila Schltr. Hyparrhenia nyassae (Rendle) Stapf Lophacme digitata Stapf Loudetia pedicellata (Stent) Chippind. Mossia intervallaris (L.Bolus) N.E.Br. Nervilia kotschyi (Rchb.f.) Schltr. var. purpurata (Rchb.f. & Sond.) Börge Pett. Panicum volutans J.G.Anderson Parapodium costatum E.Mey. Rhynchosia nitens Benth. Scirpus varius Boeck ex C.B.Clarke Tristachya biseriata Stapf Family Endemic to SA National status Province Poaceae No LC NP, MP, G Apocynaceae No LC MP, G, NP, KZN Apocynaceae No LC G, MP, FS, NW, NP, KZN Apocynaceae No LC G, NP, NW, MP Apocynaceae No LC G, NW, NP Apocynaceae No LC FS, G, NW, NC Orchidaceae No LC KZN, G, MP Poaceae No LC NP, MP, G Orchidaceae Yes LC FS, G, MP, NP Orchidaceae Yes LC KZN, G, NP Scrophulariaceae No LC G, MP, EC, FS Poaceae No LC NP, MP, G, NW Poaceae Yes LC MP, FS, NP, G, KZN Poaceae Yes LC G, NW, NP Aizoaceae No LC FS, EC, G, MP Orchidaceae No LC MP, G, NW, KZN Old status nt R R R R V R nt R K ? nt K K R nt Poaceae Apocynaceae Fabaceae Cyperaceae Poaceae K K K K K Cleome conrathii Burtt Davy (Capparaceae) This plant is known only from four small subpopulations, in the grasslands of North West, Gauteng and Northern Cape. It is threatened by overgrazing, trampling, urbanisation and has been recorded from the Suikerbosrand Nature Reserve. Status: EN B2ab(i,ii,iii,iv,v); C2a(i) (previously Indeterminate). Cucumis humifructus Stent (Cucurbitaceae) Although this species is distributed throughout tropical Yes No No No Yes LC LC LC LC LC G, NW, MP, KZN FS, KZN, G, MP, NP, NW KZN, G, MP, NP, NW NP, NW, G, MP, KZN NP, G, NW, MP Africa, it is particularly vulnerable because of its dependence on the aardvark for survival. The aardvark is the only known seed dispersal agent for this remarkable geocarpic cucurbit. It is known to occur in two regions of South Africa, namely the Waterberg and some areas of Gauteng. It is unlikely to still exist at the original locality near Cullinan in Gauteng, but may still occur at Dinokeng, a large conservancy initiative in the northeast of Gauteng. Destruction of the aardvark’s habitat is probably the greatest threat to its survival, and the fact that the aardvark is hunted for meat so their population numbers are declining. Status: EN B1ab(i,ii,iii,iv)+2ab(i,ii,iii,iv) (previously Insufficiently Known). South African Journal of Botany 2002, 68: 370–375 Delosperma gautengense H.E.K.Hartmann (Aizoaceae) Restricted to south facing slopes of the Magaliesberg and associated ridge systems, this species is threatened by trampling, habitat transformation (urban development), alien vegetation and too frequent burning. One subpopulation occurs within the Magaliesberg Protected Natural Environment. Status: EN A3cde+4cde; B1ab(i,ii,iii,iv,v) +2ab(i,ii,iii,iv,v) (previously unknown). Delosperma macellum (N.E.Br.) N.E.Br. (Aizoaceae) Only two subpopulations of this rare succulent are known, one near Vereeniging and another in Alice Glockner Nature Reserve south of Heidelberg. The species is threatened by urban development, agriculture and alien vegetation. Status: CR A3cde+4cde; C2a(i); D (not listed previously). Delosperma purpureum H.E.K.Hartman (Aizoaceae) This succulent is confined to the Witwatersrand quartzitic ridges. The main threat to its survival is habitat transformation and fragmentation through urbanisation. Status: EN A3cde+4cde; B1ab(i,ii,iii,iv,v)+2ab(i,ii,iii,iv,v); C1 (previously unknown). Delosperma vogtsii L.Bolus (Aizoaceae) This succulent herb has often been confused with D. leendertziae in the past. The species occurs on the ridges of the Magaliesberg, Sterkfontein and Krugersdorp, occupying steep south facing quartzitic slopes in grassland. The Krugersdorp subpopulation is threatened by trampling, habitat transformation, invasive vegetation, unnaturally high fire frequency and erosion. Delosperma vogtsii occurs in the Blougat Nature Reserve (Krugersdorp) and Kings Kloof Natural Heritage Site, Sterkfontein/Swartkrans/Kromdraai & Environs World Heritage Site (WHS) and Magaliesberg Protected Natural Environment. Status: EN B1ab(iii,v) +2ab(iii,v) (not listed previously). Encephalartos middelburgensis Vorster, Robbertse & S.van der Westh. (Zamiaceae) This cycad is confined to Witbank and Middelburg districts of Gauteng and Mpumalanga, where it grows in open grassland and sheltered valleys. The population numbers are estimated to have been reduced by more than 80% over the last 100 years, most of the damage being done in the 1960s by over-enthusiastic collectors. Currently threatened by illegal collecting and reproductive failure. Plants have been recorded from various private nature reserves. Status: CR A2acd+3cd (previously Endangered). Eulophia coddii A.V.Hall (Orchidaceae) This terrestrial orchid is restricted to steep slopes, growing on sandstone-derived soils in grassland or bushveld in the Waterberg (Northern Province) and in Gauteng at Heidelberg and the Magaliesberg east of Pretoria. It is 373 threatened by habitat transformation and fragmentation due to urbanisation and agriculture, as well as plant collectors. The species does occur in a provincial nature reserve. Status: EN B2ab(ii,iii,iv,v) (previously Indeterminate). Eulophia leachii Greatrex ex A.V.Hall (Orchidaceae) This orchid is distributed as far as tropical Africa, and in South Africa occurs in bushveld of Gauteng, Northern Province and KwaZulu-Natal. Very rare throughout its range, and is only known from a few localities in each country, mostly in habitats that have been transformed. Status: VU A2c (previously Indeterminate). Frithia humilis P.M.Burgoyne (Aizoaceae) Restricted to an area between Bronkhorstspruit (Gauteng) and Witbank (Mpumalanga), these succulent plants grow in very shallow soils derived from coarse sediments. The species is threatened mainly by invasive alien vegetation, trampling, overgrazing and plant collectors. The species has been recorded from a private nature reserve. Status: VU B1+2bcd (previously unknown). Frithia pulchra N.E.Br. (Aizoaceae) Confined to the Magaliesberg in the North West and Gauteng provinces west of Hartebeestpoort Dam, this species is threatened by unscrupulous succulent collectors. The species occurs within the Magaliesberg Protected Natural Environment as well as a provincial nature reserve. Status: VU D2 (previously Rare). Habenaria mossii (Williamson) J.C.Manning (Orchidaceae) This terrestrial orchid is apparently endemic to Gauteng and found growing in open grassland on dolomite or black sandy soil. Recorded from Johannesburg, Pretoria and Krugersdorp, H. mossii is threatened by urban development, but does occur in a number of Heritage sites and nature reserves. Status: EN C1+2a(i) (not listed previously). Holothrix micrantha Schltr. (Orchidaceae) This orchid is endemic to Gauteng where it grows on grassy cliffs. Threatened by urban development and related habitat degradation, the species has however been recorded from a provincial nature reserve. Status: EN A3c; B1ab(i,ii,iii,iv,v) +2ab(i,ii,iii,iv,v) (previously Insufficiently Known). Holothrix randii Rendle (Orchidaceae) This rare orchid grows on grassy slopes and rocky ledges in Gauteng and Northern Province, but also other African countries. Although not threatened on a global scale, a significant proportion of its population in South Africa is under threat from urban development. In Gauteng, the species does occur in a few small nature reserves. Status: VU B1+2ab(i,ii,iii,iv) (previously Insufficiently Known). 374 Khadia beswickii (L.Bol.) N.E.Br. (Aizoaceae) This species is endemic to Gauteng, where it grows in open areas on shallow soil over rocks in grassland. It is predominantly threatened by imminent informal urban settlement and related development, but also by alien vegetation, mining and perhaps collectors. Status: CR C1+2a(i,ii) (not listed previously). Lotononis adpressa N.E.Br. subsp. leptantha B.-E.van Wyk (Fabaceae) Endemic to Gauteng, where it is found in grassland, this species is threatened by urban and tourism-related development. Although not yet confirmed, the species may occur in the WHS and a municipal nature reserve. Status: EN B1ab(ii,iii,v)+2ab(ii,iii,v); C1+2a(i); D (previously listed as Insufficiently Known). Melolobium subspicatum Conrath. (Fabaceae) This species is endemic to Gauteng, where it grows in grassland. Melolobium subspicatum has recently been destroyed by urban development at Cornwall Hill in Irene and is assumed extinct at a second urban location, but has been confirmed from the WHS. Status: EN B1ab(i,ii,iii,iv,v) +2ab(i,ii,iii,iv,v); C1+2a(i) (not listed previously). Nerine gracilis R.A.Dyer (Amaryllidaceae) This plant grows in Mpumalanga and Gauteng in damp areas in grassland. Agricultural activities have had the most impact on this species in the past, although tourism-related development on the banks of the Vaal Dam may also threaten the species. Status: VU B2ab(ii,iii) (previously Rare). Trachyandra erythrorrhiza (Conrath) Oberm. (Asphodelaceae) This species grows in black turf marshes mainly in Gauteng but also Free State and Mpumalanga. It is threatened by habitat transformation and fragmentation through urbanisation, agriculture and invasive plant species. It is conserved in the Suikerbosrand Nature Reserve and has been recorded from the Dinokeng conservancy. Status: VU A3ce+4ce; B2ab(ii,iii,iv,v); C1+2a(i); D2 (previously listed as Insufficiently Known). Discussion There are nine taxa in Gauteng for which there is insufficient information for an assessment to be made, seven of which are new additions to the southern African Red Data plant List (Hilton-Taylor, 1996). All are listed as Data Deficient because of taxonomic uncertainty and for four of the taxa, plants are known only from their type specimens, which may be dubious species or locality records. Thirty-three Gauteng taxa that were previously listed on the Red Data List are not in danger of going extinct in the near future (of which 21 are LC and 12 NT). Twenty-three Pfab and Victor taxa were found to be threatened with extinction (of which four are CR, 12 are EN and seven are VU), with nine new additions to the Red Data List. Taxa listed on the Red Data List (Hilton-Taylor 1996) as not threatened (nt) in the former Transvaal, e.g. Eucomis autumnalis subsp. clavata, Gladiolus pretoriensis and Protea roupelliae subsp. roupelliae, are automatically classified as LC and are not considered unless there is any reason to suspect a change in status. Habitat destruction/transformation and fragmentation through urbanisation is clearly the most serious threat posed to the survival of the threatened plants of Gauteng, a trend also reported in the United States (Schemske et al. 1994, Flather et al. 1998, Foin et al. 1998). As such, stopping or reversing this habitat loss is essential (Foin et al. 1998). There is little chance that development which threatens to overwhelm subpopulations of threatened plants will cease, so it is imperative that a provincial policy is compiled to evaluate development proposals that threaten Red Data plant species and their habitat. The Gauteng Department of Agriculture, Conservation and Land Affairs (DACEL) is currently compiling such a policy. To ensure that the genetic diversity and evolutionary potential of Gauteng threatened plant species are conserved, it is vital that all subpopulations (Lammi et al. 1999) are protected from development and further fragmentation. With management and monitoring, rare plant species are able to survive and persist in large urban areas, therefore urban open spaces play an important role in biodiversity conservation (Stalter et al. 1996), provided such areas are appropriately managed. At least 74% of the 23 threatened plant taxa occur on the crests and slopes of the ridges and hills of Gauteng. The Bronberg, Magaliesberg (Pretoria) and Klipriviersberg (Johannesburg) are particularly important, together forming habitat for at least 40% of the Gauteng threatened plant taxa. In support of a multiple-species or ecosystem-level approach to threatened species conservation, it is essential that these ‘hot spot’ (Dobson et al. 1997, Flather et al. 1998) areas are protected from development, again requiring a policy for the evaluation of development applications falling within these sensitive areas. Such a policy is currently being compiled by DACEL. The Magaliesberg is already declared a Protected Natural Environment in terms of Section 16 of the Environment Conservation Act of 1989. Efforts should be concentrated on similarly protecting the Bronberg and Klipriviersberg. However, from experience the proclamation of an area as a Protected Natural Environment does not necessarily provide adequate environmental protection (Eber 2000). Therefore other legislative options should be examined such as provided for in sections 35 (formation of environmental management co-operation agreements) and 36 (expropriation of sensitive land) of the National Environmental Management Act of 1998. At least 78% of the threatened plant taxa of Gauteng occur within some sort of conservation area, ranging from fully protected provincial nature reserves to neglected municipal reserves and land under private ownership, the latter including heritage sites, private nature reserves and protected natural environments, all of which are afforded varying degrees of legislative protection. However, as the persistence of a rare species within a conservation area South African Journal of Botany 2002, 68: 370–375 cannot be taken for granted (Foin et al. 1998, Pfab and Witkowski 1999), it is imperative that the subpopulations that do grow within reserves are appropriately managed to ensure their survival. Thirty-nine percent of threatened plant species in the United States require some form of management to ensure their persistence (Foin et al. 1998). It has been noted that some consultants involved in the EIA (Environmental Impact Assessment) process, compulsory for all development projects in terms of the Environment Conservation Act of 1989 (Department of Environmental Affairs and Tourism 1998), suggest translocation as a mitigation measure when developments are impeded by the presence of threatened plants. However, translocation of threatened species is an unacceptable measure since the translocated species may disturb the ecology of its new habitat and translocation may result in rapid genetic changes of the species itself (Conant 1988, Hodder and Bullock 1997). Re-introduction of a rare plant species to a site where it historically occurred is in itself complex (Guerrant 1992, Hodder and Bullock 1997) and seldom successful as introduced populations often fail to produce the seeds and seedlings essential for recruitment of subsequent generations (Primack 1993). As such, translocations of threatened plants to previously unoccupied sites will be met with the same, if not greater, difficulties, as is the case for translocation of rare animals (Griffith et al. 1989). Of the evaluated species, 35% are collected and traded to a greater (e.g. Aloe peglerae and Encephalartos middelburgensis) or lesser degree (actual and potential) for horticultural purposes. Of these 63% are protected by legislation (the Gauteng Nature Conservation Ordinance of 1983), with Khadia beswickii and Frithia humilis currently not protected, the latter due to its very recent description as a new species. These species need to be added to the relevant schedules of the ordinance. Furthermore, it is essential that a provincial law enforcement strategy be devised and implemented to apprehend illegal collectors while they are active and to investigate local and international traders advertising these species for sale. Ex situ cultivation programmes should be established to satisfy the trade demand. We have provided the status quo as far as we know it, but would greatly encourage further contributions to our knowledge of rare plants in Gauteng. Further research would always be necessary because the conservation status of the species changes as their populations fluctuate and the full distribution ranges of some taxa may be poorly recorded. Taxonomic research (especially for Data Deficient species) would contribute to a better understanding of the conservation status of the taxa. This paper will hopefully instigate conservation action and encourage researchers and consultants to be more aware of the threatened plant taxa of Gauteng. Edited by B-E van Wyk 375 Acknowledgements — The National Botanical Institute is thanked for the use of data from the National Herbarium, Pretoria (PRE) Computerised Information System (PRECIS). 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