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Bothalia 36,2: 175-189(2006)

Patterns of diversity and endemism in

P. CRAVEN* and P VORSTER**

Keywords: Namibia, phytogeography, plant endemism

ABSTRACT

Species richness, endemism and areas that are rich in both species and endemic species were assessed and mapped for Namibia. High species diversity corresponds with zones where species overlap. These are particularly obvious where there are altitudinal variations and in high-lying areas. The endemic flora o f Namibia is rich and diverse. An estimated 16% of the total plant species in Namibia are endemic to the country. Endemics are in a wide variety o f families and sixteen genera are endemic. Factors that increase the likelihood o f endemism are mountains, hot deserts, diversity o f substrates and microclimates. The distribution of endemic to Namibia was arranged in three different ways. Firstly, based on a grid count with the phytogeographic value of the species being equal, overall endemism was mapped. Secondly, range restricted plant species were mapped individually and those with congruent distribution patterns were combined. Thirdly, localities that are important for very range-restricted species were identified. The resulting maps of endemism and diversity were compared and found to correspond in many localities. When overall endemism is compared with overall diversity, rich localities may consist o f endemic species with wide ranges. The other methods identify important localities with their own distinctive complement of species.

INTRODUCTION (1994). It was based on distributional data per magiste­ rial district following Merxmiiller (1966-1972), as well Species diversity was traditionally measured by count­ as other literature. Species diversity was re-assessed for ing the number of different species recorded in a specific the Biodiversity Country and mapped on half-degree grid area or grid (Linder 2001). The ‘weight’ of the species squares (Maggs 1998; Maggs et al. 1998). This study was not taken into consideration. Today various measures updates the underlying data used in Maggs (1998) on a of diversity have been proposed that give greater value to finer scale. species that are taxonomically, geographically, ecologi­ cally or economically distinct, but no “best' method for A taxon is endemic if confined to a particular area mapping species diversity has yet been found (Craven (Major 1988) which may be large or small. Clearly, data 2002b). The development of floristic databanks allows on endemism would be more useful if given by floristic quick and efficient retrieval of phvtogeographic data province rather than political divisions (Major 1988; that can produce computerized distribution maps. This Van Wyk & Smith 2001), but datasets between different study used the computerized data of specimens housed countries are seldom compatible in quality’ or quantity. in the National Herbarium of Namibia (WIND) and the Due to the fact that Namibia is home to a considerable National Herbarium in Pretoria (PRE) to survey distribu­ number of endemics with adequate data, this assessment tion patterns of plant diversity, overall endemism and only reviews species limited to Namibia (Figure 1). centres of endemism and diversity on a quarter-degree An endemic is therefore defined here as a taxon that is scale in Namibia. The endemic flora were also analysed restricted to within the political borders of Namibia. Taxa and factors that may have contributed to the resulting that extend marginally into another region, i.e. beyond distribution patterns were discussed briefly when evi­ the political borders of Namibia are referred to as near­ dent from the use of map overlays. Known centres of endemic. endemism were not redefined, only species with similar patterns of distribution were recorded. Centres of outstanding species diversity and endemism such as the Kaokoveld and Gariep have long attracted Caldecott et al. (1996) separated the current knowl­ attention, but their boundaries, floristic elements and edge of biodiversity into global, regional, national, origins remain fairly sketchy. Different approaches and ecoregional and site information. Patterns of diversity in methodologies have also contributed to the centres Namibia have been shown on continental-scale diversity (sometimes with the same name) not being compatible maps (Mutke et al. 2001) and included in region-based or comparable (Van Wyk & Smith 2001: Craven 2002b). studies such as those of Goldblatt (1978), Cowling et al. Stott (1981) suggested that the process consists of stages (1989) and Gibbs Russell (1985, 1987). The account of i.e. after taxonomic study (essential for elucidating Linder (2001) on patterns of plant species endemism and closely related taxonomic units) using specimens, spe­ richness for the African flora does not include arid areas cies distributions are plotted and areas of congruence such as most of Namibia, identified. The plants are then arranged into recognizable The first national assessment and map of relative groups, which on further analysis would identify phyto­ species richness in Namibia was that of Maggs et al. geographic centres determined by a high concentration of taxa with restricted distributions. This approach was pioneered in southern by Weimarck (1941) and is * To whom correspondence should be addressed: P.O. Box 399, found in taxonomic literature, for example in Nordenstam Omaruru, Namibia. ** Botany Department. University of Stellenbosch. Private Bag XI. (1969) and Hilliard (1994). The approach looks at the 7602 Matieland, Stellenbosch. geographical ranges of species regardless of their growth MS. received: 2004-07-29 form or other factors such as topography and present 176 Bothalia 36,2 (2006)

FIGURE 1.— Namibia, its neigh­ bours, capital city and some important mountains and towns. climate, and identifies particular geographical areas were variously arranged and mapped: 1, endemic fami­ inhabited by species that are restricted to these ranges. lies, genera and species individually; 2, the number of Once such a centre is recognized, explanations are sought endemic species per quarter-degree square; 3, the number on how they may have arisen (e.g. past climate) and how of quarter-degree squares in which species occurred; and they are being maintained. This knowledge is fundamen­ 4, areas where species restricted to only one or two quar­ tal to understanding the origin, migration, and speciation ter-degree squares were found. of plants and is essential for developing strategies for biological conservation. This study did not attempt to Degree scale redefine the centres presently known for Namibia, but attributes a number of new species to the centres. Quarter-degree squares were chosen for the grid scale in order to show patterns of distribution on as fine Maps presenting overall patterns of diversity and a resolution as possible and allowing small or more endemism in Namibia have been used to identify regions localized centres of diversity to be apparent. Sufficient of importance for conservation (Simmons et al. 1998; information at that scale is available for Namibia and Mendelsohn et al. 2002). This paper shows two other the total area or number of quarter-degree square grids methods of mapping important areas for endemics, which is manageable. Where no or few records were recorded should also be taken into consideration. in a quarter-degree square, the grids were ‘revisited' and any such ‘empty’ square individually rechecked and improved. Records from keyword searches and literature MATERIALS AND METHODS sources, i.e. checklists for specific areas such as those of Rodin (1985), Giess & Snyman (1986), Hines (1992) and Database Clarke (1999) as well as collections of the first author, Georeferenced specimens on the specimen database were incorporated. (SPMNDB) in WIND provided the grid-diversity count. This database has ± 120 000 specimens and includes GIS data specimens housed in PRE that were collected in Namibia. Shapefiles produced in ArcView [Environmental Sys­ All specimens of higher plants were used in the evalua­ tems Research Institute (ESR1) 2000] of Namibian fea­ tion. A sizable proportion was georeferenced following tures such as soils, topography and rainfall by the Agro- the quarter-degree square system of Edwards & Leistner Ecological Zoning Programme (1996-ongoing) and (1971). Gaps in coverage due to collecting biases and Atlas of Namibia Project (2002), as well as the positions database input errors were corrected where possible of important mountains (adapted from Irish 2002) were (Craven 2002b). The number of species present in each superimposed onto the grid-based plant data. They were quarter-degree square was calculated and mapped. used to draw accurate borders, define localities and help Distribution data for endemic species were obtained pinpoint possible reasons for the variations in diversity. from the specimen dataset as well as literature sources. Profiles showing altitude change across the country that Records for endemic species were found in 722 out of were taken at selected latitudes to cut through various over 1 200 quarter-degree squares in Namibia. These notable topographic features (Atlas of Namibia Project Bothalia 36,2 (2006) 177

2002) were also overlaid. The vertical scales have been Van Wyk & Smith (2001) point out, such areas will have exaggerated to highlight the changes in altitude. their own distinctive complement of species.

The methodology and tables used, and examples of Endemic species not included by previous authors all stages of the process, is described in more detail in were assigned to known centres, i.e. Kaokoveld. Gariep, Craven (2002b). Waterberg-Otavi and Namibia Central and Southern Highland Centres, where possible. This required looking Inventory at locality data of collected specimens for the last two centres, as elements occur at higher elevations or on a The inventory of species endemic to Namibia, taxo­ specific substrate. The large data set of georeferenced nomic limits and nomenclature of species follows Craven specimens was also used to find subcentres or more (1999). The numerous sources for endemic status and localized areas of significance. updates are listed in Craven (2002b). Genera listed as endemic follow Leistner (2000). Over 600 species

(Appendix 1) were investigated and eventually, records RESULTS for ± 540 endemic spermatophyte species were avail­ able for the analysis and maps. Not all endemics were Overall patterns of species richness and endemism included in the analysis because endemism in some genera appears inflated due to numerous infraspecific Species diversity is higher in localities where one veg­ taxa (Maggs et al. 1998), whereas other genera e.g. Cras- etation type shifts to another. Variations in altitude and sula (Crassulaceae), Euphorbia (Euphorbiaceae), Salsola the maximum altitude in any grid are also significantly (Chenopodiaceae), Tetragonia () and some in related to grid diversity (Figure 2). Only two localities in the family Mesembryanthemaceae need to be revised. the northeast region can attribute high species richness Species that are known to occur just over the border of to high rainfall. Where summer rainfall species overlap the country were not included, e.g. a number of species with winter rainfall species, however, there is an increase in the Commiphora (Burseraceae) and family in diversity, e.g. the Rosh Pinah area. Another influenc­ Acanthaceae, particularly the genus Petalidium. ing factor is mist that occurs along the Namibian coast, which may be responsible for more favourable micro­ Maps climates and increased species richness inland, e.g. the Namukluft near Rosh Pinah and Aus areas. Arcview (ESRI 2000) was used to produce the maps. Overall species richness and overall endemism could Namibian endemics were not found in the northeast, therefore be superimposed to find possible geographical which forms part of the Zambezian Domain of Wrhite correlation. Similarly, the shapefiles of the ± 540 species (1983) as this domain continues into countries further endemic to Namibia for Craven (2002b) were overlaid north. The southeast is part of the Kalahari Desert, which and the resulting maps scrutinized for congruent patterns. extends into , and no endemics were found Areas were identified and their species listed, because as there because of the general paucity of species and the

FIGURE 2.—Gnd-di\ersity for Na­ mibia depicted in five classes with altitude profiles showing correlation between changes in altitude and diversity. 178 Bothalia 36.2 (2006)

FIGURE 3.— Distribution and num­ ber of Namibian endemic gen­ era per quarter-degree grid. artificial definition of endemic used here. In the rest Genera endemic to Namibia of Namibia, the map of overall distribution of endemic species does not show any particular spatial pattern. The natural ranges of sixteen genera fall with­ Localities where the quarter-degree squares with the most in Namibia (Figure 3). They are listed in Table 1 endemics occur, are often associated with mountains in with an indication of the number of quarter-degree square grids in which they have been found. With the Namibia. The best example is the Brandberg, which also exception of the genus Ondetia (), most confirms that endemism increases when mountains are of the endemic genera occur in the central and west­ located in deserts. Substrate-specific endemic plants are ern parts of Namibia. Arthraerua (Amaranthaceae), well known and in Namibia, four Jamesbrittenia species Marlothiella (Apiaceae), Eremothamnus (Asteraceae), occur only in the limestone of the Waterberg-Otavi area Namibia, Synaptophyllum (Mesembryanthemaceae) (Hilliard 1994). Hot deserts have very high endemism and Neoluederitzia (Zygophyllaceae) occur along the in spite of their limited flora and vegetation and this has coast, whereas Baynesia () and Namacodon been shown in Namibia by the number of endemic spe­ (Campanulaceae) grow at higher altitudes. Manuleopsis cies confined to the Namib (Craven 2002b). ArcView shapefiles for physical features of Namibia, e.g. soils, TABLE 1.— Genera endemic to Namibia and the number o f quarter- aspects of climate, did not show marked patterns of simi­ degree squares in which they occur larity at this level of resolution. Family Genus No. QDS Geographical comparison of the overall pattern of Asteraceae Ondetia 42 diversity and that of endemism, as well as areas of Manuleopsis 28 importance for localized endemics and that of overall Amaranthaceae Arthraerua 18 endemics, show a degree of congruence. Important local­ Poaceae Kaokochloa 16 ized areas however, do not always coincide. Because Scrophulariaceae Chamaegigas 12 the count is based purely on the number of species or Campanulaceae Namacodon 9 endemics within that square, areas of richness cannot be Asteraceae Eremothamnus 8 distinguished by a particular combination of plant spe­ Apiaceae Phlyctidocarpa 6 cies or endemics. In addition, squares with associated Apiaceae Marlothiella 5 floral elements cannot be identified. Thus a particularly Mesembryanthemaceae Synaptophyllum 5 rich area may consist of very widespread species. Mesembryanthemaceae Namibia 3 Apocynaceae Baynesia 1 Families endemic to Namibia Mesembryanthemaceae Jensenobotrya 1 Mesembryanthemaceae Ruschianthus 1 There are no families of higher plants restricted to the Scrophulariaceae Dintera 1 political borders of Namibia. The most well-known fam­ Zygophyllaceae Neoluederitzia 1 ily that occurs only in southwest and Namibia is Welwitschiaceae. QDS. quarter-degree square. Bothalia 36,2 (2006) 179

FIGURE 4.— Distribution and num­ ber o f Namibian endemic spe­ cies per quarter-degree grid.

(Scrophulariaceae) is fairly widespread, but generally The most important families are the Mesembryan­ found on higher ground. Chamaegigas (Scrophulariaceae) themaceae. Asteraceae and Acanthaceae. The genera Aloe is a hydrophyte that inhabits pools in granite outcrops in (Asphodelaceae), Euphorbia (Euphorbiaceae). Herman- central Namibia. nia (Sterculiaceae), Jamesbrittenia (Scrophulariaceae), Petalidium (Acanthaceae), Salsola (Crassulaceae), All four genera in family Mesembryanthemaceae Stipagrostis, Eragrostis (Poaceae) and Zygophyllum occur in the winter rainfall region of southwest Namibia. (Zygophyllaceae) have the most endemic species besides Family Apiaceae, with two endemic genera, is of par­ Conophytum and (Mesembryanthemaceae), ticular interest as it has very few representatives in spe­ which have numerous infraspecific taxa. Distributions cies and number of individuals in Namibia. A recently of about 600 endemic species and certain families and described genus, Baynesia (Bruvns 2000), attests to genera are mapped in Craven (2002b). Two examples the fact that new genera may still be described in showing distinctive patterns are illustrated here. Family Namibia, especially in certain families that require revi­ Mesembryanthemaceae (Figure 5) is mainly restricted sion, e.g. Mesembryanthemaceae. Ondetia occurs close to the southwestern comer of Namibia which is also the to Botswana and may eventually be found there (Craven only area with winter rainfall. Figure 6 shows endemism & Klaassen 1998). It is very closely related to in Commiphora which occurs more commonly in the (which is presently under revision) and often mistaken north with few plants in the winter rainfall zone. Some for a Geigeria species in the field. species have very widespread distributions and are well represented in the collection, whereas others are limited There are also four near-endemic genera, i.e. they occur to one locality and one collection. One endemic was in Namibia and southwestern Angola, namely Antiphiona recorded in 195 different quarter-degree squares, and (Asteraceae), Marcelliopsis (Amaranthaceae), and nine quarter-degree squares had more than 40 endemics. Welwitschia (Welwitschiaceae). Volkiella (Cyperaceae) The quarter-degree square with the highest number of has been recorded once in Zambia. Ruschianthemum species were tabulated (Table 2) and the grid in which (Mesembryanthemaceae), which occurs just over the the Brandberg occurs is shown to have the most endemic border in the northern Cape, has been included in species, followed by the Windhoek area. Stoeberia (Chesselet & Van Wyk 2002). Species endemic to localized areas are found mainly Species endemic to Namibia in western Namibia, but also in the central regions associated with high elevations. A number of localities Approximately 600 of the nearly 4 000 indigenous were found to house four or more very restncted-range species recorded for Namibia are considered endemic species. to within the borders of the country (Figure 4) and are found in many different families and genera; 62 of the The dominant life form of the endemics of the south­ 157 families in Namibia have endemic species, whereas west winter rainfall region is succulents, whereas further 231 genera out of 958 genera have endemic species. inland, i.e. east of the Hunsberg. dwarf shrubs are more 180 Bothalia 36.2 (2006)

common. The only region with endemic trees is the have six localized endemics each. Four endemics are Kaokoveld. The distribution of endemic grasses shows found in the Sesfontein area. The family with the most them to be widespread. endemics is the Acanthaceae with five representatives and the other endemics are from a w ide variety of fami­ Namibian near-endemic species lies.

Near-endemics are defined here as species that extend Gariep Centre marginally into another region, i.e. beyond the political borders of Namibia. Two noteworthy areas for endem­ Relatively numerous local endemics were found ics and near-endemics in Namibia have been identified around Aus, the Huib Hoch Plateau to Namus Mountains, under the auspices of the IUCN Plant Conservation the Hunsberg and a section of the Warmbad District. Programme. These centres of exceptional species rich­ Species limited to these subcentres come from a variety ness and endemism (Davis & Heywood 1994) are of families and vary from grasses and geophytes to suc­ the Kaokoveld in the northwest and the Gariep in the culent Euphorbiaceae and Mesembryanthemaceae. Life southwest. Further analysis of near-endemics is needed, form type shows a certain degree of uniformity in some including the species in this study. The number of species of the subcentres. Dwarf shrubs such as Caesalpinia per quarter-degree square in the northwest and south will merxmuellerana and Petalidium cymbiforme are charac­ be higher. teristic of the endemics of the Hunsberg, whereas more succulent species, including three in Euphorbia, are Taxon phytogeographic centres found on the western side of the Hunsberg in the Numas Mountains. Three succulent mesembs are also endemic Kaokoveld Centre to the Warmbad District, namely eendornensis, Schwantesia constanceae and S. succumbens. No spe­ Considering the topography and climate, it is no cific life forms are characteristic of the Aus area, which wonder that mapped plant distributions show two main is characterized by varying substrates, or the Huib Hoch subregions besides the Brandberg, namely the coastal Plateau areas. Although field work will probably result strip, which is affected by fog and cooler temperatures, in many of these species being recorded further afield, and the inland highlands. Endemics of the coast in­ some conspicuous plants such as Caesalpinia merxmuel­ clude Ectadium rotundifolium, Merremia multisect a, lerana and Zygophyllum giessii have not been found to Hermannia gariepina and grasses such as Chloris fla- be widespread despite intense searching. bellata and Sporobolus virginicus. Most of the endemic taxa occurring on the highlands will not be found on the Waterberg-Otavi Centre coastal plains. They are more numerous and often con­ fined to mountainous areas. Additional species restricted to this centre identified here, but not necessarily only occurring on limestone, are Subcentres of importance are the Baynes Mountains Heteromorpha papillosa (Apiaceae), Pentatrichia avas- and the area around Sanitatis and Orupembe. Both areas montana (Asteraceae). Plectranthus dinteri (Laniiaceae)

FIGURE 5.—Distribution of endem­ ic plants in Mesembryanthe­ maceae and diversity per quar­ ter-degree grid. Bothalia 36,2 (2006) 181

FIGURE 6.—Distribution of endem­ ic plants m Commiphora and diversity per quarter-degree grid.

which is also in the Windhoek region, and Thesium Namibia is mapped continentally (Mutke et al. 2001), xerophyticum (Santalaceae) also on the Gamsberg. In regionally (Rebelo 1994) or nationally (Maggs et al. addition, Thesium is in need of revision and although 1994). In spite of the finer resolution used here, the most both the genera Plectranthus and Heteromorpha have species-rich areas in Namibia do not differ much from been revised, little or no field work was carried out those first indicated (Maggs et al. 1994). The differ­ in Namibia. Pentatrichia is presently under revision. ences lie in better definition of the boundaries, additional Species reported to date only from the Waterberg are localities and important smaller localities. Examples are Dintera pterocaulis (Scrophulariaceae), Eriospermum the Naukluft. Windhoek and Aus regions. The inclusion citrinum and E. lavranosii (Eriospermaceae). of the Naukluft as an important area by Maggs et al. (1994) was suspected to be an artifact of high collecting Central Namibia and Southern Highland Centre intensity and this was proved here to be the case. On the other hand, species richness in the Windhoek area Fifteen Manuleae (Scrophulariaceae) were found to is not necessarily an artifact of good collecting, despite occur in a highland centre (Hilliard 1994) that includ­ being close to a high population of potential collectors. ed the Brandberg, Erongo, Khomashochland. Auas, It includes the second highest mountain in Namibia (Irish Gamsberg. Naukluft. Tiras, Karasberg and surround­ 2002), and a number of grasses (Klaassen & Craven ing high ground, usually above ± 900 m. It excludes 2003), and other species that are not known from else­ the limestone area of the Waterberg. but may stretch where in Namibia are found here. It indicates that this into Botswana. An analysis of mapped endemics and flora includes outliers from more distant areas and is in habitat data show that numerous range-restricted spe­ agreement with Major (1988). who considers mountains cies are confined to higher elevations, as prescribed by to be mesic refugial islands, which form ideal refuges in the definition of this centre by Hilliard (1994). The flo­ times of climate change. Another area of high diversity, ristic elements range from shrubs (Nicotiana africcma) near Aus, housed a concentration camp during World and dwarf shrubs (Corchorus merxmuelleri, Hermannia merxmuelleri) to geophytes (Haemanthus uvasmontanus, War II where the interned German citizens botanized to Lapeirousia avamontana) with a tew very localized suc­ culents (Ehracleola montis-moltkei. Euphorbia montei- TABLE 2. Quarter-degree squares (QDS) with the most endemic roi subsp. brandbergensis, Aloe viridiflora). species recorded

QDS Locality No. endemic DISCUSSION spp 2114BA Brandberg area 74 Numerous hypotheses have been proposed to explain 2217CA Windhoek Auas Mtn area 63 patterns of species diversity (Schmida & W ilson 1985), 2616CB Region around town of Aus 55 but none have been found to apply well to all bodies of 2416AB East of Naukluft Mtns Farm Bullspoort 49 data. Underlying datasets and resolution can also result 2716DD Namuskluft Farm. Namus Mtns 43 in different patterns of diversity. This is seen when 182 Bothalia 36,2 (2006) pass the time. Factors that contribute to the richness of richness in Namibia, however, are ‘transitional’ areas, this area include the diverse nature of the topography (the which Shmida & Wilson (1985) define as areas between start of the escarpment) and varying substrate (scattered different ecological regions, i.e. zones in which species granite outcrops in the area) as well as the fog coming overlap. Variations in altitude and the maximum altitude inland from the coast. in any grid are significant as reported for Africa as a whole (Linder 1999). Superimposing altitudinal profiles Although the plant species diversity map is the most onto the shapefile of species richness shows this clearly detailed map of its kind for Namibia, care should be (Figure 2). It is also substantiated by studies which show taken before using it for management purposes or predic­ variations in species diversity with altitude for specific tions. Both the delimited areas and the numbers of spe­ sites or localities (Moisei 1982: Rutherford 1992). cies predicted for the regions need further refinements. Two aspects of conservation value that it does indicate Centres of diversity and endemism in Namibia, such are: 1, that many areas are more diverse than may appear as the Kaokoveld and the Gariep Centre, although lacking during periods of harsh conditions, which may last for consistency in definition, have been discussed by numer­ years or decades; and 2, the relationship between areas ous authors. Volk (1964) proposed a Kaoko Element, set aside as formal conservation areas and diversity. It is which was elaborated on by Nordenstam (1974). Hilliard apparent that certain areas of high species richness are (1994) included two taxa, Jamesbrittenia eanescens var. not afforded any formal protection. laevior and J. heucherifolia (Scrophulariaceae), which are confined to southern Angola and northern Namibia. The first map to show the overall distribution of Other authors that recognized the Kaokoveld Centre are endemic species in Namibia (Maggs et al. 1994) was Hilton-Taylor (1994a), Maggs et al. (1994), Maggs et al. based on 145 species. Endemics of southern Africa, (1998), Van Wyk & Smith (2001) and Craven (2002a). including Namibia, were mapped by Rebelo (1994). Hilton Taylor (1994b) considers the Gariep to be essen­ Differences between the latter map (regional) and the tially a geographic rather than a phytogeographic centre, present one for Namibia (national) are noticeable because but both Nordenstam (1969) and Hilliard (1994) recog­ of the scale, definition of the word endemic, and datasets nize it as a taxon phytogeographic centre of importance used. Maps published in Simmons (1998) and Simmons for numerous species. et al. (1998) were based on updated data in Maggs et al. (1997) using half-degree squares, because accord­ Mapping all Namibian endemics has shown that ing to Simmons et al. (1998), bird data show that this the distributions of many elements need to be reas­ scale reduces collecting bias. The results presented here sessed. Species presently regarded as e.g. Kaokoveld justify the use of quarter-degree, because working on a elements, ( Welwitschia mirabilis, Acanthosicyos hor- national level, more quality control of the data is pos­ ridus, Cyphostemma currorii, Acacia robymiana and sible and other sources such as literature, field work and Moringa ovalifolia) may stretch far beyond what is shapefiles of physical features can be used. An undefined generally regarded as the centre. Another example is ‘escarpment’ area was said to be the main centre for the Brandberg, which is considered an outlier of the endemic plants by Simmons et al. (1998). Overlaying a Kaokoveld Centre by Nordenstam (1974) and Hilton defined escarpment developed by the Atlas of Namibia Taylor (1994a). Provisional results of the floristic ele­ Project (2002) onto the endemic data indicates that this ments of the Brandberg (Craven & Craven 2000) show is only partially correct. Although there is an association that numerous range-restricted species also occur on between increased numbers of endemic species and the other highlands further south and it is rather a part of the escarpment, the area between the northern and southern Highland Centre as suggested by Hilliard (1994). escarpments also show localities of importance, not only in general, but also for those with limited ranges. The Kaokoveld and the Gariep Centres are basically geographic regions, so inclusion of species within the The maps resulting from this study are published by centres was based on presence or absence in the area. This the Atlas of Namibia Project (2002), where they are also is not possible with the Namibia Central and Southern combined with maps of Namibian fauna. Mendelsohn Highland Centre and the Waterberg-Otavi Centre as they et al. (2002) conclude that the most notable zones of are identified by determinants such as habitat or substrate high diversity for fauna and flora occur in the northeast, specificity. These centres do not show a clear geographic in the Karstveld around Tsumeb. in highland areas in pattern of distribution on a map until altitude contours or the centre of Namibia, and in various scattered areas of outlines of mountains are included. More endemic spe­ higher ground further west. Plant endemism was also cies will probably be included in these centres once more combined with that of animals, and Mendelsohn et al. is known about such habitat requirements. (2002) conclude that the overall patterns of endemism in Namibia are quite different from those of overall diver­ The name, Gariep, has also been used in large-scale sity. The greatest majority of endemics are found in the mapping by Jurgens (1991) despite a different approach, dry, western and northwestern regions of Namibia. On i.e. including life form and climate in the analyses. Such a regional scale of plants only (and lower resolution), approaches must not be confused with that of taxon phy­ Rebelo (1994) reports a stronger correlation between togeography as discussed here. species richness and endemicity. In general, the variable nature of most aspects of Namibian endemic plants, as in other parts of the Namibia's rainfall, as well as the paucity of overall cli­ world, are usually associated with altitude, substrate, matic data, precludes using climate at this level of resolu­ or variations in geography, which provide numerous tion. It is, however, true to say that Namibia differs from microhabitats. The most important areas for species Africa as a whole, because the most species-rich areas Bothalia 36,2 (2006) 183 are in the wetter parts of the continent (Linder 1999). http:/Vwww.dea.met.gov.na. This study highlighted the need for the microclimatic BRENAN, J.P.M. 1978. Some aspects of the phytogeography of tropical Africa. Annals of the Missouri Botanical Garden 65: conditions in which so many endemics thrive, to be stud­ 437-478. ied and documented in a systematic way. Defining these BRUYNS. PV. 2000. Baynesia. a new genus o f stapeliad from the habitats is essential to understanding the distributions of northwestern-most comer of Namibia (Apocynaceae). Novon endemic plants. The same can be said for peculiar or iso­ 10: 354-358. lated substrata (serpentine, limestone, quartzite, calcare­ CALDECOTT. J.O., JENKINS. M.D., JOHNSON, T.H. & GROOMBRIDGE. B. 1996. Priorities for conserving global ous sands) which is a widespread phenomenon in some species richness and endemism. Biodiverity & Conservation 5: areas (Major 1988; Cowling et al. 1992), and Namibia is 699-727. no exception. CHESSELET. P. & VAN WrYK. A.E. 2002. Mesembs with nut-like schizocarpic fruit and Ruschianthemum Friedrich sunk under Although distribution of endemics among life form Stoeberia. Bothalia 32: 187-190. classes was not studied here in detail, it is evident that CLARKE. N.V. 1999. Flora o f the Cuvelai wetlands, northern Namibia. Cimbebasia 15: 99-115. life forms change with locality as recorded for endemic COWLING, R.M.. GIBBS RUSSELL. G.E.. HOFFMAN. M.T. & species in general (Major 1988). This is ascribed to HILTON-TAYLOR. C. 1989. Patterns of plant species diversity climate, history of the flora and competition with the in southern Africa. In B.J. Huntley, Biotic diversity' in southern associated flora (Major 1988). Africa: concepts and consenation: 19-50. Oxford University Press. Cape Town. COWLING, R.M.. HOLMES, P.M. & REBELO. A.G. 1992. Plant Certain taxa require floristic study and field work, but diversity and endemism. In R.M. Cowling. The ecology> o f a provisional assessment suggests that a locality may fy nbos: nutrients, fire and diversity". 62-112. Oxford University be home to a variety of species from various taxonomic Press. Cape Town. groups as suggested by Cowling et al. (1992). CRAVEN, P. 1999. Checklist of Namibian plant species. Southern African Botanical Diversity Network Report No. 7. SABONET, Knowledge of local endemism will help create a bet­ Windhoek. CRAVEN, P 2002a. Plant species diversity in the Kaokoveld. ter basis for future policy (Brenan 1978). This study Namibia. In M. Bollig. E. Brunotte & T. Becker. Kaokoland— does provide sufficient information on certain aspects of Interdisziplindre Perspektiven zu Kultur- und Landschaftswandel Namibia’s endemic plants to start formulating conserva­ im ariden und semi-ariden Nordwesten Namibias: 75-80. tion strategies, but there is still a need for satisfactory Kolner Geographische Arbeiten 77. Cologne. taxonomic knowledge as well as more distribution data. CRAVEN. P. 2002b. Phytogeography of the Namibian flora: a taxon approach. M.Sc. thesis. University of Stellenbosch. It is also imperative that the information is used correctly. Stellenbosch. Simmons et al. (1998) concluded that another 11% of CRAVEN, P. & CRAVEN. D. 2000. The flora o f the Brandberg. the land area would be required to protect Namibia's Namibia. In A H. Kirk-Sprigs & E. Marais. Biodiversity o f the endemic plants. If the endemic plants already found Brandberg Massif. Namibia. Cimbebasia Memoir 9: 49-67. CRAVEN. P. & KLAASSEN. E. 1998. Ondetia, the problematic within protected areas had been removed from the data­ cousin o f vermeerbos. Spotlight on Agriculture. Ministry' of set prior to the analysis, the resulting value would be Agriculture. Water and Rural Development. Windhoek. much lower. No matter how highly a species is regarded, DAVIS. S.D. & HEYWOOD. V.H. 1994. Centres of plant diversity: as soon as it is adequately conserved, it is no longer used a guide and strategy? fo r their consen ation. Oxford University as an argument to conserve another area (Kirkpatrick Press. Oxford. EDWARDS. D. & LEISTNER. O.A. 1971. A degree reference system 1983). Because species are not spread evenly around the for citing biological records in . Mitteilungen aus world and unique concentrations may occur in relatively der Botanischen Staatssammlung. Munchen 10: 501-509. small areas, i.e. within the political borders of a country’ ENVIRONMENTAL SYSTEMS RESEARCH INSTITUTE (ESRI). like Namibia, the onus is on Namibia to protect these 2000. ArcView 3.2a Software Redlands. USA. GIBBS RUSSELL. G.E. 1985. Analysis of the size and composition of species. the southern African flora. Bothalia 15: 613-629. GIBBS RUSSELL, G.E. 1987. Preliminary floristic analysis o f the major biomes in southern Africa. Bothalia 17: 213-227. ACKNOWLEDGEMENTS GIESS. W. & SNYMAN, J.W. 1986. The naming and utilization of plant life by the Zu'hoasi Bushmen o f the Kau-Kauveld. In R The National Herbarium of Namibia, especially the Vossen & K. Keuthmann. Contemporary studies on Khoisan 1: database manager, Esmerialda Klaassen are thanked for 237-246. GOLDBLATT. P 1978. An analysis o f the flora o f southern Africa: its the use of SPMNDB. John Mendelsohn and the Atlas characteristics, relationships and origins. Annals of the Missouri team are also thanked for the final maps on diversity and Botanical Garden 65: 369 436. endemism produced for the Atlas o f Namibia. The Agro- HILLIARD, O.M. 1994. The Manuleae. A tribe of Scrophulariaceae. Ecological Zoning Programme is thanked for the use of Edinburgh University Press. Edinburgh. HILTON-TAYLOR. C. 1994a. Centres of plant diversity: Karoo-Namib shapefiles. The unpublished plant lists of Craig Hilton- region: the Kaokoveld. In S.D Davis & V.H Heywood. Centres Taylor for the Kaokoveld and Gariep Centres is greatly of plant diversity: a guide and strategy for their consenation appreciated. The contribution made by SABONET, i.e. 201-203. Oxford University Press. Oxford. the database and funding for further study, is greatly HILTON-TAYLOR. C. 1994b. Centres o f plant diversity: Karoo-Namib appreciated. region: Western Cape domain (Succulent Karoo). In S.D Davis & V.H. Heywood. Centres of plant diversity: a guide and strat­ egy fo r their consenation 204-217. Oxford University Press. Oxford. REFERENCES HINES. C.J.H 1992. An ecological study of the vegetation of eastern Bushmanland (Namibia) and its implications for de\ elopment. AGRO-ECOLOGICAL ZONING PROGRAMME. 1996-ongoing. M.Sc. thesis. Institute o f Natural Resources. University o f Natal. Directorate o f Agricultural Research and Training. Ministry of Pietermaritzburg Agriculture, Windhoek. IRISH. J 2002. Namibian mountains biodiversity potential based on ATI.AS OF NAMIBIA PROJECT. 2002. Directorate o f Environmental topography Report for the Mountain Ecosytem Working Group Affairs. Ministry o f Environment and Tourism. Windhoek of the National Biodiversity Task Force. Windhoek 184 Bothalia 36,2 (2006)

JURGENS, N. 1991. A new approach to the Namib region. I. 21-26. Phytogeographic subdivision. Vegetatio 97: 21-38. MUTKE. J.. KIER. G., BRAUN, G., SCHULTZ, C. & BARTHLOTT, KIRKPATRICK, J.B. 1983. An iterative method for establishing pri­ W. 2001. Patterns o f African diversity— a GIS- orities for the selection o f nature reserves: an example from based analysis. Systematic Geography of Plants 71: 1125- Tasmania. Biological Conservation 25: 127-134. 1136. KLAASSEN, E. & CRAVEN, P. 2003. Checklist of grasses in Namibia. NORDENSTAM, B. 1969. Phvtogeography of the genus Euryops Southern African Botanical Diversity Network Report No. 20. (Compositae). Opera Botanica 23: 1-77. SABONET, Pretoria & Windhoek. NORDENSTAM, B. 1974. The flora o f the Brandberg. Dinteria 11: LEISTNER. O.A. (ed.). 2000. Seed plants of southern Africa: families 3-67. and genera. Strelitzia 10. National Botanical Institute. Pretoria. REBELO. A.G. 1994. Iterative selection procedures: centres of ende­ LINDER. H.P 1999. Phytogeography of African plants—symposium mism and optimal placement o f reserves. In B.J. Huntley. overview. In J. Timberlake & S. Kativu. African plants: bio­ Botanical diversity in southern Africa. Strelitzia 1: 231-257. diversity, and uses: 129. Proceedings o f the 1997 National Botanical Institute, Pretoria. AETFAT Congress Harare. Zimbabwe. Royal Botanic Gardens, RODIN, R.J. 1985. The ethnobotany of the Kwanvama Ovambos. Kew. Monographs in Systematic Botany 9: 1-165. LINDER. H.P. 2001. Plant diversity and endemism in sub-Saharan RUTHERFORD. M.C. 1992. Notes on the flora and vegetation of the tropical Africa. Journal of Biogeographv 28: 169-182. Omuverume Plateau-Mountain. Waterberg, South West Africa. MAGGS, G.L. 1998. Plant diversity in Namibia. In P Bamard. Dinteria 8: 3-55. Biological diversity in Namibia: a country study: 116-122. The SCHMIDA, A. & WILSON, M.V. 1985. Biological determinants of Namibian National Biodiversity Task Force. Windhoek. species diversity. Journal of Biogeography 12: 1-20. MAGGS. G.L., CRAVEN, P. & KOLBERG. H.H. 1998. Plant spe­ SIMMONS, R E. 1998. Areas of high species endemism. In P. Bamard. cies richness, endemism and genetic resources in Namibia. Biological diversity in Namibia: a country study '. 72-74. The Biodiversity & Conservation 7: 435—446. Namibian National Biodiversity Task Force, Windhoek. MAGGS, G.L., CRAVEN, P., KUBIRSKE, R.. KLAASSEN, E.S., SIMMONS, R.E.. GRIFFIN, M„ GRIFFIN. R.E.. MARAIS, E. & MANNHEIMER, C.A. & UIRAS. M.M. 1997. Flora of Namibia. KOLBERG, H. 1998. Endemism in Namibia: patterns, proc­ Report for the Annual Research Reporting Conference. Ministry esses and predictions. Biodiversity & Conservation 7: 513-530. o f Agriculture. Water and Rural Development, Windhoek. STOTT, P. 1981. Historical plant geography: an introduction. Allen & MAGGS, G.L., KOLBERG, H.H. & HINES, C.J.H. 1994. Botanical Unwin, London. diversity in Namibia— an overview. In B.J. Huntley, Botanical VAN WYK. A.E. & SMITH. G.F. 2001. Regions offloristic endemism diversity in southern Africa. Strelitzia 1: 93-104. National in southern Africa. A review with emphasis on succulents. Botanical Institute, Pretoria. Umdaus Press, Pretoria. MAJOR, J. 1988. Endemism: a botanical perspective. In A.A. Myers & VOLK. O H. 1964. Die afro-meridionale-occidentale Floren-Region PS. Giller, Analytical biogeography. An integrated approach to in Sudwestafrika. Beitrdge zur Phytologie zu Ehren Prof. H the study of animat and plant distributions: 117-146. Chapman Walters 65 Geburtatages. Ulmar, Stuttgart. & Hall. London. WEIMARCK, H. 1941. Phytogeographical groups, centres and inter­ MENDELSOHN, J„ JARVIS. A., ROBERTS, C. & ROBERTSON, A. vals within the Cape flora. Lunds Universitets Arsskrift N.F.Afd. 2002. Atlas of Namibia: a portrait of the land and its people. 2,37: 1-143. David Phillip Publishers, Cape Town. WHITE, F. 1983. The vegetation of Africa: a descriptive mem­ MERXMULLER. H. (ed.). 1966-1972. Prodromus einer Flora von oir to accompany the UNESCO/AERFAT/UNSO vegetation Sudwestafrika. Cramer, Lehre. map of Africa. United Nations Educational Scientific Cultural MOISEL, L. 1982. Wanderungen im Brandbergmassiv. Dinteria 16: Organization, Paris.

APPENDIX 1.— List of Namibian endemic plants used in the evaluation

= Species name in italics indicates a synonym used in the original evaluation. * Endemic species not used in the evaluation due to lack of data or species described since the evaluation. • Species that have been collected outside Namibia since the evaluation. Unless otherw ise stated, species indicated by • are near-endemic and mainly based on collections of Craven or Bruyns, particularly from Angola.

Acanthaceae grandiflorum Schinz Barleria leucoderme (Schinz) C.B. Clarke •damarensis T.Anderson serotinum P. G. Mey. dinteri Oberm. tonsum P.G.Mey. jubata S. Moore Peristrophe kaloxytona Lindau grandibracteata Lindau lanceolata (Schinz) Oberm. hereroensis (Schinz) K.Balkwill meeuseana P. G. Mey. namibiensis K Balkwill merxmuellen P.G.Mey. subsp. brandbergensis K Balkwill solitaria P.G.Mey. subsp. namibiensis Blepharis Petalidium ferox P. G. Mey. canescens (Engl.) C.B.Clarke fleckii P.G.Mey. cymbiforme Schinz gigantea Oberm. giessii P.G.Mey. meyeri Vollesen lanatum (Engl.) C B.Clarke pruinosa Engl. linifolium T.Anderson spinifex Merxm. luteo-album A.Meeuse Hygrophila gracillima (Schinz} Burkill *ohopohense PG.Mey. Justicia pilosi-bracteolatum Merxm & Hainz cuneata Vahl subsp. hoerleiniana (P.G.Mey.) Immelman guerkeana Schinz ramulosum Schinz •platysepala (S.Moore) P.G.Mey rautanenn Schinz Monechma subcnspum PG.Mey. calcaratum Schinz Rhmacanthus kaokoensis K Balkwill & S. Williamson callothamnum Munday Ruellia crassiusculum P.G.Mey. aspera (Schinz) E. Phillips desertorum (Engl.) CB. Clarke brandbergensis Kers Bothalia 36,2 (2006) 185

Aizoaceae Stapelia Aizoanthemum kwebensis N.E.Br. = Stapelia longipedicellata (A.Berger) N.E.Br., dinteri (Schinz) Friedrich not endemic galenioides (.Fenzl ex Sond.) Friedrich pearsonii N.E.Br. rehmannii (Schinz) H.E.K.Hartmann = Aizoanthemum membrum- *remota R.A.Dyer connectens Dinter ex Friedrich schinzii A.Berger & Schltr. Aizoon giessii Friedrich *var. bergeriana (Dinter) L.C.Leach Tetragonia var. schinzii rangeana Engl. •Stapeliopsis umiflora Lavranos •schenckii (Schinzj Engl. Stigmatorhynchus hereroensis Schltr. Trianthema hereroensis Schinz Tridentea marientalensis (Nel) L.C.Leach subsp. albipilosa (Giess) L.C.Leach Alliaceae •pachyrrhiza (Dinter) L. C. Leach Tulbaghia calcarea Engl. c& K.Krause. insufT. known Tromotriche ruschiana (Dinter) Bruyns Amaranthaceae •Tylophora fleckii (Schltr.) N.E.Br. Arthraerua leubnitziae (Kuntze) Schinz Aponogetonaceae Calicorema squarrosa (Schinz) Schinz Aponogeton azureus H.Bruggen Hermbstaedtia spathulifolia (Engl.) Baker Marcelliopsis splendens (Schinz) Schinz Asphodelaceae Aloe Ammocharis nerinoides (Baker) Lehmiller argenticauda Merxm. & Giess Crinum asperifolia A.Berger paludosum I. Verd. corallina I. Verd. rautanenianum Schinz dewinteri Giess Haemanthus avasmontanus Dinter •dinteri A Berger *Namaquanula bruynsii Snijman erinacea D.S. Hardy * pusilla Dinter * hereroensis Engl. var. lutea A Berger Strumaria namibensis Giess hardyana D.Mull.-Doblies & U.Mull.-Doblies omavandae Van Jaarsv. phonolithica Dinter pachygaster Dinter sladeniana Pole Evans Anacardiaceae viridiflora Rey nolds Rhus Bulbine problematodes Merxm. Roessler caput-medusae G. Will. volkii Suess. francescae G. Will. & Baijnath namaensis Schinz Apiaceae praemorsa = Bulbine tetraphvlla Dinter. not endemic Anginon streyi (Merxm.) I.Allison & B -E van Wyk *rhopalophvlla Dinter Heteromorpha papillosa C.C. Towns. Trachyandra Marlothiella gummifera H. Wolff ensifolia (Solch) Roessler Phlyctidocarpa flava Cannon & W.L. Theob. glandulosa (Dinter) Oberm. Polemanniopsis sp. = Merxmuller & Giess 32010 lanata (Dinter) Oberm. peculiaris (Dinter) Oberm Apocynaceae •Australluma peschii = Carallumapeschii Nel Asteraceae Baynesia lophophora Bruyns thuja (Merxm.) Koekemoer Brachystelma Anisopappus blepharanthera H. Huber pinnatifidus (Klatt) O.Hoffm. ex Hutch codonanthum Bruyns pseudopinnatifidus S.Ortiz & Paiva recurvatum Bruyns Antiphiona schinzii (K.Schum.) N.E.Br. fragrans (Merxm.) Merxm schultzei (Schltr.) Bruyns pinnatisecta (S. Moore) Merxm. •C'eropegia dinteri Schltr. Arctotis frutescens T.Norl. Cynanchum meyeri (Decne.) Schltr. Aspilia eenii S. Moore Ectadium Berkheya schinzii O.Hoffm latifolium (Schinz) N.E.Br marlothiana O.Hoffm. rotundifolium (H.Huber) Venter & Kotze ^Chrysocoma puberula Merxm. •Gomphocarpus semiplectens K.Schum Crassocephalum coeruleum (O.Hoffm.) R E.Fr Dauresia alliariifolia (O.Hoffm.) B Nord & Pelser = Senecio alliari- juttae Dinter ifolius O.Hoffm. officinalis (N.E.Br.) Plowes subsp. delaetiana (Dinter) Bruyns Dicoma ruschii Dinter cuneneensis H 'ild triebneri (Nel) Bruyns dinteri S.Moore Huemia ’ obconica S. Ortiz <£ Pulgar hallii E.Lamb dï B M.Lamb Eremothamnus marlothianus O Hoffm. plowesii L C.Leach Eriocephalus Larryleachia tirasmontana Plowes Lavraniapicta (N.E.Br.) Plowes dinteri S. Moore subsp pan ipunctata Bruyns giessii M A N.Muller haagnerae Plowes kingesii Merxm <£• Eberle M icroloma k 1 inghardtensis M A N. Muller hereroense Wanntorp pinnatus O Hoffm penicillatum Schltr Euryops Orbea mucosus B.Nord albocastanea (Marloth) Bruyns walterorum Merxm maculata (N.E.Br.) L.CLeach Felicia •subsp kaokoensis Bruyns alba Grau subsp. rangeana (Dinter <& A.Berger) Bruyns gunillae B.Nord. Raphionacme smaragdina (S Moore) Merxm haeneliae Venter A R.L.Verh. •(iaruleum schinzii O.Hoffm subsp cnmtum (Dinter/ Merxm namibiana Venter & R.L.Verh. Gazania thermalis Dinter Bothalia 36,2 (2006) 186

Geigeria kraeuseliana Heine odontoptera O.Hoffm. •saxicola Engl. omativa O.Hoffm. subsp. omativa var. filifolia (Mattf.) S.Ortiz & •virgata Engl. Rodr.Oubina = G. englerana Muschl. & Geigeria otaviensis (Merxm.) Merxm. Campanulaceae pilifera Hutch. Namacodon schinzianum (Markgr.) Thulin plumosa Muschl. Wahlenbergia *subsp. angustifolia S. Ortiz & Rodr. Oubifia densicaulis Brehmer subsp. brachycephala S.Ortiz & Rodr.Oubina = G. brachvcephala erophiloides Markgr. Muschl. *intricata (Dinter <£ Markgraf) P.Craven. ined. = Lightfootia dinteri rigida O.Hoffm. Engl, ex Dinter Gorteria diffusa Thunb. subsp. parviligulata Roessler subumbellata Markgr. Helichrysum amboense Schinz Capparaceae deserticola Hilliard Cleome erubescens Hilliard camosa (Pax) Gilg & Gilg-Ben. marlothianum O.Hoffm. foliosa Hook.f. var. namibensis (Kers) Codd Lasiopogon labumifolia Roessler ponticulus Hilliard suffruticosa Schinz volkii (B.Nord.) Hilliard Myxopappus hereroensis (O.Hoffm.) Kállersjó Chenopodiaceae *Chenopodium amboanum (Murr) Aellen heterophylla S. Moore Salsola subsp. affinis (S.Moore) Merxm. albisepala Aellen subsp. heterophylla arborea C.A.Sm. ex Aellen Nidorella nordenstamii Wild *aroabica Botsch. tenuifolia Mattf. campyloptera Botsch. ♦Norlindhia aptera B.Nord. cauliflora Botsch. Ondetia linearis Benth. columnaris Botsch. Osteospermum cryptoptera Aellen montanum Klatt muricatum E.Mey. ex DC. subsp. longiradiatum T.Norl. denudata Botsch. dinteri Botsch. Othonna brandbergensis B.Nord. dolichostigma Botsch. clavifolia Marloth etoshensis Botsch. •graveolens O.Hoffm. •garubica Botsch sparsiflora (S.Moore) B.Nord. gemmata Botsch. Pegolettia giessii Botsch. pinnatilobata (Klatt) O.Hoffm. ex Dinter hoanibica Botsch. plumosa M.D.Hend. hottentottica Botsch. Pentatrichia huabica Botsch. avasmontana Merxm. kleinfonteini Botsch. rehmii (Merxm.) Merxm. koichabica Botsch. *Philyrophyllum brandbergense P.P.J.Herman marginata Botsch. tomentosa B.Nord. mirabilis Botsch. Pteronia namibica Botsch. eenii S. Moore okaukuejensis Botsch. polygalifolia O.Hoffm. *omaruruensis Botsch. pomonae Merxm. *parviflora Botsch. rangei Muschl. procera Botsch. spinulosa E. Phillips ptiloptera Botsch. Rennera eenii (S. Moore) Kállersjó robinsonii Botsch. Senecio engleranus O.Hoffm. *schreiberae Botsch. giessii Merxm. scopiformis Botsch hermannii B.Nord. seminuda Botsch. windhoekensis Merxm. *seydelii Botsch. Sphaeranthus wattii Giess ex Merxm spenceri Botsch. Tripteris nervosa Hutch. swakopmundi Botsch Ursinia frutescens Dinter ugabica Botsch Vemonia unjabica Botsch. obionifolia O.Hoffm Suaeda subsp. dentata Merxm articulata Aellen subsp. obionifolia salina B.Nord.

Boraginaceae Colchicaceae *Ehretia namibiensis Retief A.E.van Wyk subsp. kaokoensis Retief & Androcymbium exiguum Roessler subsp. exiguum A.E van Wyk Omithoglossum calcicola K. Krause & Dinter Heliotropium albiflorum Engl. •Trichodesma angustifolium Harv. subsp. argenteum Retief <£ A.E.van Convolvulaceae Wyk Convolvulus argillicola Pilg Merremia Brassicaceae bipinnatipartita (Engl.) Hallierf. Heliophila * deserticola Schltr. var. micrantha A.Schreib. guerichii A Meeuse obibensis Marais Crassulaceae Burseraceae Adromischus Commiphora schuldtianus (Poelln.) Poelln ’ dinten Engl •subsp. brandbergensis B.Nord. cS Van Jaarsv giessii J.J.A.van der Walt subsp. juttae (Poelln ) Toelken *kaokoensis WSwanepoel subsp. schuldtianus Bothalia 36,2 (2006) 187

Crassula Eriosema harmsiana Dinter aurusbergensis G. Will. Erythrina decora Harms ausensis Hutchison Haematoxylum dinteri (Harms) Harms subsp. ausensis Indigofera subsp. giessii (Friedrich) Toelken acanthoclada Dinter *subsp. titanopsis Pavelka anabibensis A.Schreib. elegans Schdnland & Baker f subsp. namibensis (Friedrich) giessii A.Schreib. Toelken hochstetteri Baker subsp. streyana (Merxm.) A.Schreib. luederitzii Schdnland merxmuelleri A.Schreib. numaisensis Friedrich pechuelii Kuntze Tylecodon rautanenii Bakerf. aridimontanus G. Will. Lebeckia ""aurusbergensis G. Will. & Van Jaarsv. dinteri Harms obovata Schinz Cucurhitaceae Lessertia Citrullus rehmii De Winter acanthorhachis (Dinter) Dinter Cucumella clavipetiolata J.H.Kirkbr. cryptantha Dinter eremicola Dinter Cyperaceae Lotononis •Bulbostylis mucronata C.B Clarke bracteosa B.-E.van Wyk Cyperus rehmii Merxm. mirabilis Dinter pachvcarpa Dinter ex B.-E.van Wyk Ebenaceae Euclea asperrima Friedr.-Holzh. pallidirosea Dinter & Harms schreiberi B.-E.van Wyk Eriospermaceae Sesbania pachycarpa DC. subsp. dinterana J.B.Gillett Eriospermum Tephrosia buchubergense Dinter, insufT. known gnseola H.ML.Forbes citrinum P.L.Perry monophylla Schinz flexum PL.Perry pallida H.M L.Forbes *graniticolum Dinter ex Poelln., insuff. known halenbergense Dinter Frankeniaceae lavranosii P.L.Perry’ Frankenia pomonensis Pohnert volkmanniae Dinter Geraniaceae Monsonia Euphorbiaceae deserticola Dinter ex R.Knuth Euphorbia drudeana Schinz angrae N.E.Br ignorata Merxm. á A.Schreib. baliola N.E.Br. trilobata Kers caperonioides R. A.Dyer & P.G.Mey. Pelargonium chamaesycoides B.Nord. cortusifolium L Her. •cibdela N.E.Br mirabile Dinter damarana L.C.Leach otaviense R.Knuth friedrichiae Dinter paniculatum Jacq. giessii L.C.Leach insarmentosa P. G. Mey. Sarcocaulon inerme Rehm juttae Dinter marlothii Engl. kaokoensis (A C. White. R.A.Dyer & B.Sloane) L.C.Leach lavrani L.C.Leach peniculinum Moffett leistneri R.H.Archer Hyacinthaceae mauritanica L. var. foetens Dinter ex A C. White, R. A.Dyer & Albuca B.Sloane amboensis (Schinz) Oberm. monteiroi Hook.f. subsp. brandbergensis B.Nord *englerana K Krause & Dinter namibensis Marloth hereroensis Schinz namuskluftensis L.C.Leach *karasbergensis PE.Glover otjipembana L.C.Leach *reflexa Dinter <5 K.Krause pergracilis P.G.Mey’. Drimia *pseudoduseimata A C. White, R.A.Dyer

Moraea Fenestraria rhopalophylla (Schltr. & Diels) N.E.Br subsp. rhopalo- garipensis Goldblatt phylla *graniticola Goldblatt Jensenobotrya lossowiana A.G.J.Herre hexaglottis Goldblatt Juttadinteria namibensis Goldblatt attenuata Walgate rigidifolia Goldblatt •ausensis (L.Bolus) Schwantes deserticola (Marloth) Schwantes Kirkiaceae simpsonii (Dinter) Schwantes dewinteri Merxm. & Heine Lithops dinteri Schwantes Lamiaceae subsp. dinteri Acrotome fleckii (Giirke) Launert •subsp. multipunctata (de Boer) D.T.Cole Aeollanthus namibiensis Ryding Hemizygia floccosa Launert * franc i sc i (Dinter & Schwantes) N.E.Br. ♦gracilidelineata Dinter subsp. brandbergensis (de Boer) D.T.Cole Plectranthus dinteri Briq. *hermetica D. T. Cole unguentarius Codd julii (Dinter & Schwantes) N.E.Br. subsp. julii Stachys dinteri Launert karasmontana (Dinter & Schwantes) N.E.Br. •Tetradenia kaokoensis Van Jaarsv. & A.E.van Wyk *subsp. bella (N.E.Br.) D.T.Cole •subsp. eberlanzii (Dinter & Schwantes) D.T.Cole Lobeliaceae •optica (Marloth) N.E.Br. Lobelia hereroensis Schinz pseudotruncatella (A.Berger) N.E.Br •subsp. archerae (de Boer) D.T.Cole Loranthaceae •subsp. dendritica (Nel) D.T.Cole Agelanthus discolor (Schinz) Balle •subsp. volkii (Schwantes ex de Boer & Boom) D.T.Cole Lythraceae •ruschiorum (Dinter & Schwantes) N.E.Br. Nesaea luederitzii Koehne var. hereroensis Koehne schwantesii Dinter •subsp. gebseri (de Boer) D.T.Cole M alvaceae subsp. schwantesii Hibiscus •vallis-manae (Dinter & Schwantes) N.E.Br dinteri Hochr. wemeri Schwantes ex H. Jacobsen discophorus Hochr. •Malephora engleriana (Dinter & A.Berger) Schwantes fleckii Giirke Mesembryanthemum pellitum Friedrich merxmuelleri Roessler Namibia sulfuranthus Ulbr. cinerea (Marloth) Dinter & Schwantes = Namibia ponderosa Pavonia rehmannii Szyszyl. (Dinter & Schwantes) Dinter & Schwantes pomonae (Dinter) Dinter & Schw antes ex Walgate Mesembryanthemaceae Psammophora Amphibolia saginata (L.Bolus) H.E.K. Hartmann •nissenii (Dinter) Dinter & Schwantes Antimima •saxicola H.E.K.Hartmann argentea (L.Bolus) H.E.K.Hartmann Psilocaulon aurasensis H.E.K.Hartmann gessertianum (Dinter & A Berger) Dinter & Schwantes buchubergensis (Dinter) H.E.K.Hartmann dolomitica (Dinter) H.E.K.Hartmann •salicomioides (Pax) Schwantes eendomensis (Dinter) H.E.K.Hartmann modesta (L.Bolus) H.E.K.Hartmann deminuta L.Bolus quarzitica (Dinter) H.E.K.Hartmann •namusmontana Friedrich Astridia hallii L.Bolus •odontocalyx (Schltr. & Diels) Schwantes Brownanthus •pollardii Friedrich •arenosus (Schinz) Ihlenf. & Bittrich •ruschiana (Dinter) Dinter & Schwantes namibensis (Marloth) Bullock vulvaria (Dinter) Schwantes pubescens (N.E.Br. ex Maasss) Bullock Ruschianthus falcatus L.Bolus Cephalophyllum Schwantesia •compressum L.Bolus constanceae N.Zimm confusum (Dinter) Dinter & Schwantes succumbens (Dinter) Dinter Cheiridopsis caroli-schmidtii (Dinter & A Berger) N.E.Br. Synaptophyllum juttae (Dinter & A Berger) N.E.Br. Conophytum •Titanopsis schwantesii (Schwantes) Schwantes halenbergense (Dinter & Schw antes) N.E Br. •Trichodiadema littlewoodii L.Bolus klinghardtense Rawe subsp. baradii (Rawe) S.A.Hammer Molluginaceae subsp. klinghardtense •Corbichonia rubriviolacea (Friedrich) Jeffrey quaesitum (N.E.Br.) N.E.Br subsp. densipunctum (L Bolus) Hypertelis caespitosa Friedrich S. A. Hammer Mollugo walteri Friedrich ricardianum Loesch & Tischer Suessenguthiella caespitosa Friedrich subsp. ricardianum subsp. rubiflorum Tischer Nyctaginaceae taylorianum (Dinter & Schwantes) N.E Br Boerhavia deserticola Codd subsp. emianum (Loesch & Tischer) de Boer ex S.A.Hammer Commicarpus subsp. taylorianum •decipiens Meikle klinghardtianum Schwantes fruticosus Pohnert microspermus (Dinter & Derenb.) Schwantes subsp. impunctatus N.Sauer Orobanchaceae •Dracophilus delaetinus (Dinter) Dinter & Schw antes Alectra Drosanthemum pseudobarleriae (Dinter) Dinter nordenstamii L.Bolus schoenfelden Dinter & Melch pauper (Dinter) Dinter á Schw antes Eberlanzia clausa (Dinter) Schwantes Oxalidaceae Ebracteola Oxalis derenbergiana (Dinter) Dinter & Schw antes ausensis R.Knuth montis-moltkei (Dinter) Dinter & Schwantes hunsbergensis ined. Bothalia 36,2 (2006)

Oxalis (cont.) Jamesbrittenia luederitzii Schinz acutiloba (Pilg.) Hilliard pseudo-cemua R.Knuth barbata Hilliard schaeferi R.Knuth bicolor (Dinter) Hilliard chenopodioides Hilliard dolomitica Hilliard • pechuelii (Engl.) Harms fimbnata Hilliard fleckii (Thell.) Hilliard Rogeria bigibbosa Engl. fragilis (Pilg.) Hilliard Sesamothamnus leistneranus, ined. = De Winter <£ Leistner 5504 giessii Hilliard Sesamum hereroensis (Engl.) Hilliard abbreviatum Merxm. lyperioides (Engl.) Hilliard marlothii Engl. pallida (Pilg.) Hilliard pilgeriana (Dinter) Hilliard Plumbaginaceae primuliflora (Thell.) Hilliard Limonium dyeri Lincz. sessilifolia (Diels) Hilliard Plumbago Manulea pearsonii L. Bolus dubia (Skan) Oxerkott ex Roessler wissii Friedrich namibensis (Roessler) Hilliard Poaceae tenella Hilliard "■Brachiaria schoenfelden C.E.Hubb. A Schweick. Manuleopsis dinteri Thell. Eragrostis Nemesia aristata De Winter karasbergensis L Bolus kingesii De Winter violiflora Roessler omahekensis De Winter •Phyllopodium hispidulum (Thell.) Hilliard pygmaea De Winter Selago sabinae Launert amboensis Rolfe scopelophila Pilg. lepida Hilliard stenothyrsa Pilg. walteri Pilg. nachtigalii Rolfe •Kaokochloa nigrirostris De Winter Solanaceae Merxmuellera rangei (Pilg.) Conert *Panicum pearsonii F. Bolus Lycium grandicalyx Joubert A A.M. Venter Pennisetum foermeranum Leeke Nicotiana africana Merxm. Pogonarthria leiarthra Hack. Solanum Setaria finita Launert damarense Bitter Sporobolus nebulosus Hack, (endemic to southern Africa) dinteri Bitter Stipagrostis rigescentoides Hutch. •damarensis (Mez) De Winter garubensis (Pilg.) De Winter Sterculiaceae gonatostachys (Pilg.) De Winter Dombeya rotundifolia (Hochst.) Planch, var. velutina I. Verd. •hermannii (Mez) De Winter Hermannia lanipes (Mez) De Winter amabilis Marloth ex K.Schum namibensis De Winter *complicata Engl. pellytronis De Winter elliottiana (H an.) K.Schum •ramulosa De Winter engleri Schinz sabulicola (Pilg.) De Winter glandulosissima Engl. seelyae De Winter juttae Dinter A Engl. Polygalaceae merxmuelleri Friedr.-Holzh •Polygala guerichiana Engl. minimifolia Friedr.-Holzh solaniflora K.Schum. Portulacaceae Anacampseros filamentosa (Haw.) Sims subsp. tomentosa (A.Berger) Tecophilaeaceae Gerbaulet •Eremiolinon amboensis = Cyanella amboensis Schinz Avonia dinteri (Schinz) G.D Rowley = Anacampseros dinteri Schinz •Ceraria longipedunculata Merxm A Podlech Tiliaceae Corchorus merxmuelleri Wild Kubiaceae Amphiasma Turneraceae divaricatum (Engl.) Bremek Tumera oculata Story var. paucipilosa Oberm merenskyanum Bremek. Kohautia amboensis (Schinz) Bremek Priva auricoccea A Meeuse azurea (Dinter t£ K Krause) Bremek Vitaceae Santalaceae Cyphostemma Thesium xerophyticum A. W.Hill bainesii (Hook.f) Desc. Scrophulariaceae •juttae (Dinter A Gilg) Desc Anticharis omburense (Gilg A M. Brandt) Desc ebracteata Schinz Zygophyllaceae imbncata Schinz inflata Marloth A Engl Neoluederitzia senceocarpa Schinz Aptosimum Zygophyllum arenarium Engl. applanatum Van Zyl suberosum FE Weber cylindnfolium Schinz C'hamaegigas intrepidus Dinter ex Heil giessii Merxm A A.Schreib C'romidon pusillum (Roessler) Hilliard hirticaule Van Zyl Diclis tenuissima Pilg. longistipulatum Schinz Dintera pterocaulis Stapf •stapffii Schinz. previously known as Z orbiculatum in Angola