A checklist of vascular plants of the Amatole Mountains, eastern Cape Province/Ciskei

A checklist of vascular plants of the Amatole Mountains is presented. The physical environment, climate and vegetation of the study area and the history of its botanical exploration are described. The mountains form part of the Winterberg Range in the eastern Cape/Ciskei region of south-eastern Africa, and cover an area of approxi­ mately 900 km2. The altitude ranges from about 700 m to 2 000 m above sea level, and the topography is very varied. The climate is warm temperate and supports various vegetation types including forest, sclerophyllous shrubland, grassland and marshland. The checklist records the occurrence of 1 215 taxa. The largest families and genera in the area contain predominantly grassland herbs. Many of the characteristic families of the Cape Floristic Region and of the arid areas of southern Africa are poorly represented in the Amatole Mountains.


INTRO DUCTIO N
The A m atole M ountains in the south-east of southern A frica are of particular botanical and eco logical interest for a num ber of reasons. The M oun tains lie in a region where six m ajor African phytochoria m eet. These are the Indian Ocean Coastal Belt, the Sudano-Zam bezian Region, the Karoo-Namib Region, the Cape Region and the Afro-montane archipelago with its associated Afro-alpine areas (W erger 1978). The M ountains receive a rela tively high rainfall, and act as an im portant drainage sponge for the neighbouring lower lying semi-arid areas. The indigenous forests and marshlands are believed to be particularly im portant in this respect.
State forestry plantations and residential areas are responsible for the introduction of many exotic species, some of which have become naturalized. The establishm ent of forest plantations and the en croachm ent of exotics into natural vegetation have had a very significant effect on the indigenous flora and on the ecology of the area as a whole.
The A m atole M ountains have been known to bot anists since the early nineteenth century, and have gradually becom e relatively thoroughly explored. They have long been recognized as an area with a high species diversity, but little precise inform ation has been available about their flora.
The aim of this work is to provide a reliable and com prehensive checklist of the vascular plants of the A m atole M ountains which can serve as a basic refer ence for taxonom ic, floristic and ecological research, and for educational purposes in the future.

Physical Environm ent
The name A m atole (or A m atola) M ountains has been applied to a vaguely-defined section of the W interberg Range, centred on the well known Hogsback Ridges. In the present study they are d e fined as bounded by the Kat and Esk Rivers in the north-w est and the Thom as and Keiskamma Rivers in the east. The bottom edge of the escarpm ent forms the southern edge, while an arbitrary line across the African surface plateau connecting the Esk and Thom as Rivers forms the northern bound ary (Figure 1). Defined in this way the A m atole M ountains form an area of about 900 km 2, lying within the latitudes 32° and 33° S, and longitudes 26° and 28° E.
The A m atole M ountains are part of a long outly ing spur of the high interior plateau of southern Africa. The spur extends south-east and then east from the G reat Escarpm ent, gradually loosing height and disappearing near the town of Stutterheim. It has been breached by the Fish River, which separates the A m atoles and other m ountains of the W interberg Range to the east from the B ankberg, B ruintjeshoogte and Tandjesberg Ranges to the west.
The W interberg Range has a steep, irregular es carpm ent facing south, which rises above the 'Post-A frican' erosion surface. To the north of the escarp m ent, the land, which forms part of the older 'A fri can' erosion surface, slopes gradually into the basins of the Fish and Kei Rivers. Rem nants of the still older 'G ondw ana' erosion surface remain as scat tered peaks, ridges and mesas above the African surface plateau.
The escarpm ent of the Am atole M ountains falls from the African surface plateau at about 1 500 m to between 700 and 1 000 m, broken in many places by an interm ediate platform at about 1 250 m. Above the plateau the highest m ountain peaks reach about 2 000 m. The most prom inent of the peaks are shown in Figure 1.
The W interberg Range consists of dolerite sheets, dikes and sills intruded into weak shales and sand stones of the Karoo sequence (Beaufort G roup). The resistant dolerite has strongly influenced the landscape, helping to m aintain the prom inent es carpm ent and the G ondw ana remains, and also caus ing a num ber of less im portant features. The geo m orphology of the Hogsback area was described in more detail by Agnew (1958).

Climate
The climate of the Am atole M outains is warm tem perate, characterized by high rainfall, cold win ters and m oderately warm summers relative to other parts of southern Africa.
Moist air from the south is forced upwards by the escarpm ent and results in rainfall of between 750 and 1 500 mm per annum, increasing from lower to higher altitudes (Story 1952). Behind the escarp ment and on north-facing slopes the rain shadow decreases the rainfall, while local topographic effects may increase it in certain places. Rainfall is more evenly spread throughout the year than is common in many parts of southern Africa, although it is high est in sum m er, with a peak in February. On the es carpm ent and south-facing mountain slopes fog is com m on, and mist gauges have recorded 20 -30% gains over the standard precipitation (S. Russell pers. com m .).
At the Hogsback settlem ent (about 1 250 m) the annual average tem perature is about 15 °C, with ab solute maxima and minima of 40° in sum m er and -6°3 2 4 5 1S 32°45'S in w inter respectively, with some snow falling in most years. Obviously altitude and topography influ ence tem peratures, and very much colder conditions are found at the summits of the main peaks.

Vegetation
The vegetation of the A m atole M ountains is pre dom inantly A fro-m ontane in affinity (W hite 1978, 1983), and many typical A fro-m ontane species reach their southern limit in this region. In addition the M ountains contain a significant Cape elem ent in their flora, together with many SE African endem ics. They fall within an area of Highland and Dohne Sourveld in the vegetation classification of Acocks (1975).
The high rainfall in the A m atole M ountains is able to support well developed high forest. These forests are floristically rich, containing both evergreen and deciduous species, with large specimens of Podocarpus falcatus being particularly prom inent. Well pre served forest is present on most of the escarpm ent slopes, and in some areas of the interm ediate plat form. On the m ountain peaks, above the plateau, some forest/w oodland patches are found in sheltered areas, mainly in south-facing positions. These patches are poor in species and are probably above the altitudinal limit for many forest tree species in this region.
The plateau areas and m ountain slopes are largely grass-covered. This 'sour' grassland has provided good grazing land for domestic stock, and this has given rise to the M ountains' nam e. Am atole (or A m atola) is derived from the Xhosa word amathole, the plural of ithole, m eaning calves. Oral history de scribes the large herds of cattle owned by pastoralists in the days of Param ount Chief Sandile. These herds thrived on the rich grassland and produced many calves, and the area eventually became known as the 'm ountains of calves' (iintabe zakwamathole) (Pahl pers. com m .). Excessive grazing by domestic stock can severely reduce grass cover, and this may lead to soil erosion. Serious erosion has occurred in some localities, particularly near the base of the escarp m ent. A t higher altitudes bare ground does not ap pear prone to excessive erosion, and is usually colo nized by unpalatable herbs and small shrubs which help to stabilize the soil surface. Helichrysum argyrophyllum, in particular, covers large areas that have been overgrazed, and once it is established, re growth of grasses appears to be very slow. Grassland in the A m atole M ountains contains a large num ber of herbs which are highly responsive to fire, being inconspicuous in m oribund grassland, but flowering prolifically after burning.
In many places the vegetation is dom inated by sclerophyllous shrubs growing up to about 3 m tall. Such areas are relatively poor in species, with Cliffortia spp., Erica brownleeae, Passerina spp. and Stoebe spp. predom inating. These communities are often referred to as 'false-m acchia' to distinguish them from the true macchia (fynbos) of the Cape region and can colonize grassland areas very rapidly. It is not certain w hether they represent a climax stage, or m erely a step in the succession from grass land to forest. In many localities old stands of falsem acchia may contain forest pioneer species such as Buddleja salvifolia, Halleria lucida and Rapanea melanophloeos, and probably in the more sheltered localities the succession could procede to forest, while in the more exposed areas a mixed false-macchia/woodland may result. The false-macchia com m unities are very sensitive to fire, and controlled burning program m es have been em ployed success fully in elim inating sclerophyllous shrubs and pro moting the re-establishm ent of pasture grasses. Overgrazing pratices may encourage the encroach m ent of false-macchia. The agricultural m anagem ent of vegetation in the A m atole M ountains has been discussed by Trollope (1973).
The summits of the highest peaks reach into the Sub-alpine Belt of the Afro-alpine Region (Killick 1978), where a m ontane m oorland vegetation oc curs. On rocky areas this consists of small sclero phyllous shrubs, growing to a height of about 0,5 m, often with scattered small trees of Protea subvestita. These shrubs may include Arrowsmithia styphelioides, Chrysocoma tenuifolia, Cliffortia paucistaminea, Erica spp., Euryops dyeri, Muraltia spp. and Passerina montana, with Restio sejunctus and Thamnocalamus tesselata also common. Elsewhere on the summits grassland may occur with Agrostis spp., Aristida junciform is subsp. galpinii and Festuca spp. predom inating. Little is known about the ecology of the summit vegetation.
D epressions in level areas may support patches of m arshland. These are usually dom inated by species of C yperaceae, although the invasion of some m ar shes near G aika's Kop by Phragmites australis has been noted. M an has certainly had a significant influence on the vegetation of the A m atole M ountains over a long period of time. Since about 1850 forestry activi ties and the developm ent of the Hogsback residen tial/recreational area have caused the introduction of a large num ber of exotic species. A num ber of eco nomically im portant forest trees have been planted in the region, and some of these have becom e natu ralized. The Hogsback settlem ent is well known as a place where tem perate garden plants will flourish, and some of these have also become naturalized. M ost of the naturalized exotics in the A m atole M ountains are confined to disturbed ground near plantations and cultivated ground, and most have failed to encroach significantly on the natural vege tation. Im portant exceptions are Acacia mearnsii, Pinus spp., Rubus fruticosus and certain grasses, no tably Stipa trichotoma, which have becom e wide spread.

HISTORY OF BO TANICAL EXPLORATION IN THE AM ATO LE M OUNTAINS
The earliest known preserved botanical specimens from the A m atole M ountains are those collected by C. F. Ecklon and C. L. P. Zeyher in 1831/2. Their contem porary, J. F. D rêge, and earlier collectors such as W. J. Burchell and C. P. Thunberg collected in neighbouring areas, but did not actually visit the A m atole M ountains (G unn & Codd 1981). Ecklon and Z eyher collected on "Schum iberg', the m ountain now known as Juanasberg. While collecting in the area they probably stayed at Tyumie Mission, which had been founded by Rev. J. Brownlee in 1820. Brownlee was himself a keen am ateur botanist, but he only started preserving plant specimens after moving to King W illiam's Town in 1825 (G unn & Codd 1981). During this early period the Am atole M ountains must have been very inaccessible, and further botanical exploration was probably pre vented by the series of frontier wars which continued until 1847. In 1860 T. C ooper visited the area, and collected extensively, particularly on Elandsberg.
Soon a num ber of forest stations were set up along the W interberg, and gradually the mountains be came more accessible (Sim 1907). As botanical ex ploration of southern Africa proceeded, many im portant collectors of the late nineteenth century visi ted parts of the W interberg, but little m aterial was collected in the A m atole Mountains. The Pirie M ountains in the east, and the Boschberg to the west of the W interberg were extensively explored by T. R. Sim and P. Macowan respectively. J. Buchanan collected grasses and ferns in the Amatole M oun tains while he was stationed at Lovedale Mission from 1876 to 1877, and Sim and W. G. Bennie also made some collections in the area (Sim 1915;Gunn & Codd 1981). However, in general the flora of the area rem ained poorly known.
In the early part of the twentieth century G. R at tray made extensive collections in the Am atole M ountains, mainly at Hogsback, and some other im portant collectors visited the area at this time. In 1934 systematic botanical exploration of the M oun tains commenced with the appointm ent of M. H. Giffen as the lecturer in Botany at the nearby South African Native College (now the University of Fort H are). Giffen collected extensively during the 1930's and 1940's but unfortunately did not distribute du plicate specimens. His main interest was in diatoms and his collections of other plant groups did not re ceive the attention they deserved (M .H. Giffen pers. com m .).
In 1947 R. Story com m enced a botanical survey of the Keiskam m ahoek District, which includes a por tion of the Am atole M ountains, but also includes part of the Pirie M ountains and some lower lying areas (Story 1952). This work is im portant, not only with respect to the specimens collected, but also in providing a basic ecological account of the District.
Since the mid-1950's regular student field excur sions to the Hogsback area have been organized by A. R. A. Noel, A. Jacot Guillarmod and R. A. Lubke of Rhodes University, Graham stown, which formed the basis of an unpublished checklist. Speci mens collected on these visits are housed at R U H , but have not been critically identified. Since 1975 staff and students at the University of Fort Hare have continued collecting in the Am atole M oun tains, and a num ber of ecological research projects have been carried out. Field work undertaken for the present study was concentrated on the more poorly collected localities, habitats and taxa, in o r der to give a more thorough coverage of the flora of the area. The Giffen collections were finally identi fied and labelled ap.H his duplicate specimens and other collections were distributed by G. E. Gibbs Russell. By July 1986 nearly 3000 specimens of vas cular plants from the Am atole M ountains had accu mulated in the Herbarium of the D epartm ent of Plant Sciences at the University (U F H ), and these form the basis of the present checklist.
The A m atole M ountains have been visited by many botanists from other institutions during the past 20 to 30 years, and they have become botanically well explored in comparison with many areas of southern Africa.

CHECKLIST
The present checklist of vascular plants was com piled from a num ber of sources. The specimens at UFH have been examined and identified using the relevant Floras and monographs. In problematic cases com parison of material with authentically de term ined specimens in other herbaria has been made. In many cases, specimens of taxa currently under revision have been seen by or discussed with the taxonom ists concerned. Specimens at U FH thus form the basis of the checklist. Duplicate material has been distributed to many other herbaria, but the main duplicate sets are held at K, MO and PRE.
Records of additional taxa have been obtained directly from taxonomic literature where a locality within the study area has been specifically m en tioned. An extensive search of the available litera ture was made for such records, and these have been cited in full in the checklist.
No attem pt has been made to systematically search for m aterial from the Am atole M ountains in other herbaria, however a comparison was made with the com puterized record (PRECIS) of the col lections at PR E . Duplicates of the historically im portant C ooper, Sim and Rattray collections, to gether with many recent collections, are listed and these were checked against the present checklist. In a sample section of about a sixth of the PRECIS record no additional taxa were found.
In the course of field work for the present study a few sight records of additional taxa were m ade, and these are given in the checklist. N om enclature follows the list of accepted taxa at PRE (Gibbs Russell et al. 1984, 1985, except where more recent treatm ents are available. Every effort has been made to ensure that the checklist was taxonomically and nomenclaturally up-to-date on com pletion in D ecem ber 1986.
Most of the largest families and genera are groups containing predom inantly grassland herbs, notably the A steraceae and the Poaceae, and this reflects the high diversity of species found in this habitat in the Am atole M ountains. T here is also a large num ber of species of C yperaceae, a family characteristic of marshland habitats. Taxa typical of forest habitats are only represented, in these figures, by the rela tively small genera A splenium and Cheilanthes (both Pteridophytes), and the sclerophyllous vegetation only by the genus Erica.
Com parison of the figures given above with those given by G oldblatt (1978) for the whole of southern Africa show some similarities in the relative propor tions of many taxa. The most noticeable differences in the flora of the A m atole M ountains is the low num ber of species of Ericaceae, Proteaceae and R estionaceae, characteristic families of the Cape Floral R egion, and of M esem bryanthem aceae (in cluded in A izoaceae by G oldblatt), which are con centrated in arid areas.
Some specim ens belonging to genera which are currently in a state of taxonom ic confusion or cur rently under revision could not be identified, these include Alchem illa, Erica, Harveya, Hypoxis, Indigofera, Lotononis, Pentaschistis, Senecio and W ah lenbergia. O th er genera contain probable new species, these include Cliffortia, Cineraria, Conium, Crassula, Fuirena, Helichrysum, Passerina, Pentzia, Stoebe and Watsonia. Some naturalized exotics re corded in the A m atole M ountains, but lacking voucher specim ens, were not identified to species level, and the record of Othonna sp. is based on an unsubstantiated literature reference. In some cases, specimens of species divided into varieties or subspe cies could not be assigned to these taxa with cer tainty.