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Lists the paper and books published by South African Association of Botanists members in 2001.

• South Africa is not spared from the adverse effects of climate change which alters the ecosystem and have a ripple effect on food security. • This paper reviewed the impacts of climate change on the phenology, physiology, and economic benefits of wild fruits and vegetables in South Africa. • The possible productivity of wild fruits and vegetables was evaluated with spatial-based data through land use/land cover which showed that South Africa had varied vegetation and land cover dynamics. • There is a need to develop cultivation strategies for edible wild fruits and vegetables to expand knowledge and create options in utilizing the wild species. • This will boost the country's economy, help to improve diet, and can play a crucial role in food security. Overdependence on exotic plant species constitutes a major setback for the consumption of wild fruits and vegetables among South Africans. The country is not spared from the adverse effects of climate change which play a substantial role in altering the ecosystem and have a ripple effect on food security. Wild fruits and vegetables have been identified to be underutilized despite the country's struggle in nourishing its population. This paper reviewed the impacts of climate change on the phenology, physiology, and economic benefits of wild fruits and vegetables in South Africa. Furthermore, spatial-based data was used to evaluate the possible productivity of wild fruits and vegetables through land use/land cover (LULC) assessment. The result showed that South Africa had varied vegetation and land cover dynamics. For example, Northern Cape and Western Cape Provinces are dominated by shrubland and barren land, thus unsuitable for fruit and vegetable production. In contrast, Limpopo, North-West, Mpumalanga, Gauteng, Free State, some parts of KwaZulu-Natal and Eastern Cape Provinces are covered with grassland and cultivated areas which made them good for vegetable farming and potential ground for wild fruit and vegetable cultivation. Thus, there is a need to develop cultivation strategies for edible wild fruits and vegetables with known nutritional characteristics to expand knowledge about nutritional benefits and options in utilizing the wild species. This will boost the country's economy, help to improve diet, and can play a crucial role in food security. [ABSTRACT FROM AUTHOR]

• Cowpea is a highly valued fruit and leafy vegetable crop contributing to food, nutrition, and health security. • Low cowpea production and productivity in sub-Saharan Africa and globally are due to a lack of improved cultivars with multiple disease, and insect pest resistance and drought tolerant; moreover, there is a lack of seed system research in cowpea. • The extensive phenotypic and genotypic variation found in cowpea genetic resources is useful for the development of cultivars with enhanced grain yield, leafy yield and nutritional values as well as drought tolerant. Despite the contribution of cowpeas to food security and the crop's numerous nutritional and health attributes, consumers in South Africa have labelled cowpeas, among other leguminous crops as a "poor people's food" ; this contributed to the gradual decline in the cultivation and use of the crop. This, in turn, resulted in the observed high reliance on limited number of plant based protein crops and excessive consumption of livestock products. In this paper, three aspects are interrogated, i.e., genetic resource management, production constraints as well as the trade performance and consumption of cowpeas in South Africa. A clear understanding of these aspects renders an informed decision upon which recommendations for the necessary practical interventions that are needed to be put in place to spur the development of target products and cowpea's value chain. The assessment of genetic resource management and seed production constraints of cowpeas was based on a review of relevant literature, while descriptive analysis of secondary data spanning a period of 10 years (2010-2019) obtained from Trade Map and FAOSTAT databases was used to interrogate the trade performance and consumption of cowpeas. Findings reveal that seed production constraints are largely anchored on the limited attention government and policy making institutions have accorded to the seed system of orphaned crops, thereby compromising their potential by failing to supply affordable good quality seeds to smallholder and commercial farmers. However, South Africa has one of the largest and most diverse collections of cowpea germplasm housed at the Agricultural Research Council. With regard to trade performance and consumption, results show that South Africa is a net exporter of cowpeas, with a 10 years' period annual average worth R2.9 million. Given that South Africa does not re-export cowpeas, yet on average 4848 tonnes are produced annually, it is a clear indication that the country produces lightly more than what is consumed domestically – on average 4634 tonnes per annum. Therefore, recommendation is made to bolster cowpea production and productivity through mainstreaming the legume seed system towards boosting local and export markets as well as strongly enhancing local consumption by creating awareness of the nutritional and health benefits of cowpeas. Furthermore, there is a need to increase awareness about the nutritional and health benefits of cowpeas and other leguminous crops, among other socio-economic benefits. This is important in spurring cowpeas consumption domestically, while countering the over reliance on animal products as protein sources and the associated risks such as such as high greenhouse gas emissions and obesity for people. [ABSTRACT FROM AUTHOR]

• The highly invasive Nassella neesiana, N. tenuissima and N. trichotoma are naturalised in high altitude mountain grasslands of South Africa. • The current knowledge of Nassella invasion dynamics is based on limited research mainly done before the 1990s or research being done in Australia and New Zealand. • Current control methods are not coping with invasions. • There's a potential to use biological agents to control Nassella invasions. • There are many knowledge gaps that require urgent research in order to effectively manage invasions. Three species of Nassella have naturalized in South Africa. Nassella trichotoma and N. tenuissima are declared weeds under category 1b of the National Environmental Management: Biodiversity Act (NEM:BA) and occur mainly in the montane grasslands of the Western and Eastern Cape provinces. Nassella neesiana is not listed in NEM:BA but is naturalized in the Eastern Cape, Western Cape and Free State provinces. Research conducted in the 1970s and 1980s led to vigorous government-funded awareness and control campaigns which ended in 2000. No research on Nassella distribution or control has been undertaken since then. Despite this hiatus, Nassella remains a dangerous genus in southern Africa, given the serious impacts of these species in similar social-ecological systems in Australia and New Zealand. This paper presents a synthesis of available information about Nassella invasions in South Africa and identifies research gaps. It specifically addresses these questions: What identification issues exist? What is the current spatial distribution of Nassella ? What is the autecology of the genus? What are the social-ecological impacts of Nassella ? What control measures are currently applied and what are their strengths and limitations? What do we know about Nassella distribution and its response to climate change? This paper highlights many knowledge gaps about Nassella, such as the species' current distribution range, field identification and detection difficulties, and the uncoordinated control efforts that require urgent research to inform an effective management response. [ABSTRACT FROM AUTHOR]

Food security is threatened in Southern Africa, because of unpredictable droughts and higher summer temperatures brought on by climate change and global warming. Durable and hardy plants that grow easily and quickly in such conditions must be adopted to ensure sustainable and reliable food supplies. The young cladodes (nopalitos) from the cactus pear plant, which adapts to hot and dry climates, is an underutilised alternative food source that can serve as a healthy vegetable. It thrives in many environments such as deserts, below sea level, high altitude regions and tropical regions with temperatures above 50°C. Nopalitos are a traditional staple vegetable and have been consumed in Mexico for over 9000 years. However, it is underutilised and unknown as an alternative vegetable in Africa. Research on the physiochemical and nutritional content has been conducted. However, the information on harvesting nopalitos from cultivars available in South Africa for optimal edible quality is not available. Good quality nopalitos are young, thin, bright green, soft, fresh and not too sour or slimy. This paper aims to identify the effect of and the interaction between size, cultivar and harvesting season to obtain optimal eating quality. Data were obtained for two cultivars (Morado and Fusicaulis) at 9 cm, 12 cm, 15 cm, 18 cm, 21 cm and 24 cm, which were harvested in spring (October) and autumn (March) over two years. The quality characteristics were translated into the measurable attributes of morphology (weight, width, diameter, volume and surface area), texture (firmness and compressibility), colour (L*, a*, b*, C*and h°), turgidity (moisture content, mucilage yield and viscosity) and gustatory (percentage titratable acidity, pH and total soluble solids). ANOVA and Principal Component Analyses were performed to determine significant differences and interactions between the length groups, two cultivars and two seasons. The results showed that the size, cultivar and season influenced the edible characteristics. Both cultivars were most tender at 15 cm and presented the best edible qualities in spring. Morado showed better colour, turgidity and gustatory qualities. Morado was thinner, a brighter green colour, less sour and less slimy compared to Fusicaulis nopalitos. • Nopalito quality is highly influenced by harvest size, cultivar and season. • At 15 cm, nopalitos from both Morado and Fusicaulis were the most tender. • Morado nopalitos was the preferred cultivar, but Fusicaulis also performed satisfactorily. • Spring harvest was preferable, but autumn harvest nopalitos were acceptable. • Morado was thinner, a brighter green colour, less sour and less slimy. [ABSTRACT FROM AUTHOR]

South Africa's unique flora and extensive use of African traditional medicines has created a unique research opportunity on medicinal plants for local and international scientists. In this paper, submitted to a special issue of South African Journal of Botany (SAJB) dedicated to "sub-Saharan Ethnobotany", we aim to explore the research landscape on medicinal plant research as published in SAJB. A bibliometric assessment (1982–2017) showed that medicinal plant research represents 24% of the published volume in SAJB and that contributions on this topic are increasing exponentially. Although most papers are broad-based invitro screening studies, the range of topics covered is impressive. Antimicrobial (41%) and anti-oxidant (21%) studies dominate the research space with fewer studies focusing on diseases highly relevant to the African continent, e.g. malaria (3%) and tuberculosis (2%). Although the SAJB has contributed greatly to disseminating knowledge on important species (e.g. Aspalathus and Cyclopia) several taxa of potential economic relevance remain poorly investigated (e.g. Adansonia , Bulbine etc.). The citation footprint and authorship networks which have been established attest the pivotal role the SAJB has played to build research capacity and create awareness in this important field of research. • Medicinal plant papers contributed 24% of papers published in SAJB (1982–2017). • The 629 papers considered attracted 6313 citations. • In vitro studies represented 89% of experimental papers. • Highest number of published papers were antimicrobial (41%) and anti-oxidant (21%). • Few studies focused on relevant diseases like tuberculosis (2%) and malaria (3%). [ABSTRACT FROM AUTHOR]

Moringa is widely distributed across the globe for its multiple uses as well as high nutritive content and great economic attributes; subsequently it has been highly commercialised. Even though moringa is fast becoming an important crop in several parts of the world, in South African context, it is not recognised for such, and is listed on the Species Under Surveillance for Possible Eradication or Containment Targets (SUSPECT) under National Environmental Management Biodiversity Act (NEM:BA), since it is not native to South Africa. Where it is established in South Africa, people perceive the numerous qualities of moringa as beneficial and this can result in conflict generation between communities and policy makers who have to safe guard against alien and invasive species spread and impact. In this paper, we review the ecological, social and legal status of moringa in South Africa, and highlight the importance of conducting research on non-native species with the focus of improving evidence base prior listing of species on national regulations. Moreover, we highlight the need to also focus on social aspects of invasive species, using a cost–benefit approach to assist in decision making regarding control, management and eradication of moringa and other non-native plants. • In South Africa, moringa is on the Species Under Surveillance for Possible Eradication or Containment Targets (SUSPECT). • Moringa has the potential to be a conflict-generating species, particularly between communities and policy makers. • Listing of non-native species under NEMBA should be guided by impact-based evidence to ascertain their risks and benefits. [ABSTRACT FROM AUTHOR]

Thesium L., section Hagnothesium is endemic to the Greater Cape Floristic Region (GCFR), South Africa. In the past there has been a propensity in revisionary work of the section Hagnothesium to split taxa into distinct species or vice-versa. Consequently, 15 different names exist although only 6 are accepted formally. Following recent molecular phylogenetic studies, the monophyly of the section Hagnothesium is now well-established but the circumscription of species within the section remains problematic given the complicated nomenclatural history which has added further confusion. In this paper we revise the section using a total evidence approach to propose a revised taxonomy. We studied both herbarium collections as well as plants in their natural populations to circumscribe species boundaries, determine their geographical ranges and estimate their conservation statuses. Species of the section Hagnothesium are dioecious, generally having four-merous campanulate flowers produced in spikes borne in bract axils and arranged along the length of branchlets, with valvate perianth lobes and a short to absent hypanthial tube. We recognise eight species, of which one is described in this study as new: T. fragile L.f., T. fruticulosum (A.W.Hill) J.C.Manning & F.Forest, T. hirtum (Sond.) Zhigila, Verboom & Muasya comb. nov., T. leptostachyum A.DC., T. longicaule Zhigila, Verboom & Muasya nom. nov. T. microcarpum A.DC., T. minus (A.W.Hill) J.C.Manning & F.Forest) and T. quartzicolum Zhigila, Verboom & Muasya sp. nov. We provide updated taxonomic keys, species descriptions, illustrations, distribution maps, new combinations, synonyms, and notes on the red list status for each species. • A review is given of Thesium section Hagnothesium (Santalaceae) an endemic clade to the GCFR. • Eight species are recognised, of which one, T. quartzicolum is described here as a new. • Key to the species in section Hagnothesium is provided • Species delimitations and nomenclatural changes are provided. • Species geographical ranges and the estimate of their conservation statuses are provided. [ABSTRACT FROM AUTHOR]

This paper reported for the first time the aroma profile and essential oil composition of eight species of Helichrysum endemic in South Africa but grown in Italy (CREA-Sanremo collection). The volatiles of all the studied Helichrysum were dominated by monoterpene hydrocarbons, except for H. basalticum , where sesquiterpene hydrocarbons was the main class of compounds with β-caryophyllene (13.7%) and α-guaiene (11.9%) as major components. Despite the great diversity of compounds obtained in the volatile emission (more than 130), only four compounds were responsible for at least 34% of the identified fraction. These compounds were: sabinene (16.0%), β-caryophyllene and α-guaiene in H. basalticum ; sabinene (57.7%) in H. foetidum ; (Z)-β-ocimene (34.6%), tricyclene (16.2%) and myrcene (10.0%) in H. incanatum ; myrcene (29.3%), tricyclene (21.5%) and limonene in H. indicum ; tricyclene (32.1%) and (E)-3-hexanol acetate (20.1%) in H. montanum ; limonene (10.3%), sabinene (8.9%), 1-decene (7.6%) and 1-hexanol (7.0%) in H. mutabile ; α- and β-pinene in H. patulum (27.6% and 44.9%, respectively) and α-pinene (36.3%) and α-fanchene(15.6%) in H. setosum. The EOs composition of these species was also different from each other with sesquiterpene compounds as the prevalent class. Valerianol (16.3%, os, in H. basalticum), ledol (16.3%, os, in H. foetidum), β-caryophyllene (11.0% and 13.4%, sh, in H. indicum and H. patulum , respectively), viridiflorol (18.3%, os, in H. montanum) and valerianol (30.1%, os in H. setosum) were found to be the main constituents. It is worthy to highlighting that the H. incarnatum EO showed a similar behaviour to that of the spontaneous emission with a predominance of monoterpene hydrocarbons (60.7% in EO vs 81.4% in VOC), both represented by (Z)-β-ocimene as main constituent. • First chemotaxonomic characterisation of eight South African Helichrysum spp. • These South African were grown in the same edaphic and climatic conditions. • Monoterpene hydrocarbons dominated VOC samples except for H. basalticum. • Sesquiterpenes had the highest percentage in seven EO samples. • Helichrysum incarnatum EO was characterised by high amount of monoterpenes. [ABSTRACT FROM AUTHOR]

Over the past decade, a series of controversies has arisen about equity and justice in the rooibos industry, centred both on the biological resource and on the traditional use and knowledge that fostered the growth of this lucrative trade. Accusations of biopiracy, meaning the misappropriation and patenting of genetic resources and knowledge without consent, have taken centre stage, leading to a reassessment of the conditions under which rooibos is traded. Claiming to be the primary holders of traditional knowledge relating to rooibos, indigenous San and Khoi have also launched demands—to date unmet—for a stake in rooibos benefits. Meanwhile, small-scale coloured rooibos producers, despite their involvement in fair trade, remain marginalized. All remain embedded in a political history of rooibos that is characterized by dispossession and adversity, having been propped up by the South African apartheid system. The melding of these issues with a complex and ambiguous legal framework has led to a situation described by some as “the mother” and “testing ground” of so-called access and benefit sharing. Such approaches stem in part from the Convention on Biological Diversity and its Nagoya Protocol, which lay down new and more equitable ways of treating trade in genetic resources and the use of traditional knowledge. With growing international interest in rooibos tea and its bioactive compounds, a surge of patents associated with the plant, the successful granting of geographical indication status, and threats to the industry of changing climates, ecologies and ecosystems, the stage is set for a reconceptualization and transformation of the industry. Drawing on longitudinal research over the past 20 years, this review paper aims to bring conceptual clarity and a holistic analysis to an often emotional, divided and, to date, narrowly framed debate. Through exploration of rooibos histories and traditional knowledge claims, bioprospecting and patent activities, and conservation imperatives, this paper reviews the spectrum of issues that require attention when considering access and benefit sharing in the rooibos industry and provides suggestions for a more integrative, environmentally responsive and just approach. [ABSTRACT FROM AUTHOR]

Abstract Rubus L. is a highly diverse and taxonomically complex genus with a worldwide distribution. Although southern Africa is not a major centre of Rubus diversity, a number of indigenous and naturalised taxa have been recorded from the region, although their taxonomy, nomenclature and evolution are either confused or poorly studied at best. This paper represents the first results of a wider project focusing on the biosystematics of the southern African Rubus flora, and presents a taxonomic revision of the brambles of the Cape Floristic Region, including an estimation of ploidy levels. A total of eight taxa are recognised, including the two indigenous taxa R. pinnatus and R. rigidus agg., the four introduced species R. armeniacus , R. bergii , R. rosifolius and R. titanus , and two hybrids between indigenous and introduced taxa. Rubus rigidus agg. is an unresolved and variable species complex with at least two ploidy levels (5x, 6x). The hybrid taxon R. bergii × R. rigidus appears to be widespread and behaves as an independent apomictic complex. In addition, hybridization between R. bergii and R. pinnatus is relatively common in the contact zones between the two species. The two introductions Rubus armeniacus and R. titanus are recorded from South Africa for the first time. The invasive potential of the introduced species is regarded as low but the potential for hybridization by R. bergii seems to be high. An identification key, morphological descriptions, and notes on nomenclature, distribution and ecology are provided, and all taxa are illustrated. Highlights • Rubus is revised for the CFR. • Eight native and naturalised taxa are recognised. • Rubus armeniacus and R. titanus are recorded from South Africa for the first time. • All taxa are described and fully illustrated. [ABSTRACT FROM AUTHOR]

Abstract The purpose of this paper is to give an ecological description of the vegetation of the Jurisdam-Seekoegat section of the Mountain Zebra National Park in the Eastern Cape Province, South Africa. The effect of different land use practices on the vegetation composition was also investigated. Vegetation classifications and descriptions are of immense value to scientists and land managers and provide information on the composition, structure, diversity and effect of management on the different ecosystems present. The Braun-Blanquet approach was used to classify the different plant communities, while the veld condition was determined using the Ecological Index Method. Plant community data was analysed using the JUICE software package while diversity of the different plant communities was determined using the Shannon–Wiener and Gini–Simpson Indices. From a TWINSPAN analysis eight plant communities that can be grouped into six major communities were identified. Two plant communities not previously described for the Park were identified. The different plant communities can all be related to topography and effect of previous land use. Grasses and dwarf shrubs are the most prominent species. The plant communities of the rocky midslope areas achieved the highest species richness and diversity for the study area. The areas least affected by heavy grazing had a higher veld condition score than those heavily grazed by domestic animals in the past. The results of this study also emphasises the importance of resting overgrazed veld, while it seems that heavily grazed areas will not recover without further human intervention. A vegetation map of the different plant communities was produced using ArcGIS. Highlights • Vegetation classification improves our knowledge and understanding of complex ecosystems. • Rocky hilly areas act as refuge areas for vegetation with the highest diversity of plant species. • Resting of overgrazed veld in arid areas assists in veld condition recovery. • Wildlife has less of an impact on veld condition than domestic animals with continued grazing. • Overgrazing seems to alter nutrient structure of soil thereby altering vegetation composition. [ABSTRACT FROM AUTHOR]

The common wetland vegetation types categorized as temperate grassy wetlands have tall or medium tall graminoids that are found in the Highveld and other grassland areas in South Africa, but can extend into other biomes. The data on temperate grassy wetlands were extracted from a nationwide wetland vegetation database, consisting partly of historical vegetation data and partly newly collected data. A classification of these vegetation types took place using cluster analysis. Some of the vegetation data contained detailed soil parameters, which were used in canonical ordination to illustrate which environmental variables have the most impact on these vegetation types. Temperate grassy wetlands consist of twenty-five communities, which have been summarized in this paper into thirteen community groups. These wetlands occur over a wide altitudinal range as many of the species occurring in them have broad ecological amplitudes and are competitive even outside of their optimum range. The environmental variables that were the most important in explaining both the variation in the dataset and the vegetation types were wetness and altitude. [ABSTRACT FROM AUTHOR]

This paper presents the first detailed assessment of the invasive potential of Melaleuca hypericifolia Sm. in South Africa. This woody, fire-adapted shrub, native to Australia, is considered a high risk invader which could potentially occupy 4% of the country if allowed to spread. As such, it is a listed invader under South African legislation. Melaleuca hypericifolia is known to have naturalised at five sites in the Western and Eastern Cape of South Africa and several introduced but non-spreading populations represent a further risk of invasion. An integrated management approach involving mechanical and chemical control was tested on an invasive population (20.4 ha extent) on Chapman's Peak in Cape Town, Western Cape Province. Management interventions began in 2012 and were repeated annually. The number of reproducing individuals was reduced over the four year period reported on here. The treatment used was shown to be effective as no re-sprouting occurred although some plants were overlooked during clearing operations owing to the density of the surrounding native vegetation. Low detectability presents a major impediment to extirpation of the population despite the distinctive flowers and leaf arrangement of this species. We recommend the use of fire where feasible to increase visibility and stimulate seed germination. We estimate that extirpation of M. hypericifolia from the Chapman's Peak site will be possible with an annual investment of ZAR 10000 over the next 10 years. Uncertainty around the extent of plantings of Melaleuca hypericifolia around the country limits the suitability of the species as a national eradication target. However, based on the invasive risk it poses and given encouraging results from the extirpation effort as shown in this study, we conclude that site-specific extirpation is a feasible management goal for this species. [ABSTRACT FROM AUTHOR]

The South African rocky subtidal and intertidal habitats are rich in diversity and abundance of non-geniculate coralline red algae. Despite their ubiquity, they are still a comparatively poorly known group of marine organisms. Ongoing taxonomic changes have meant that the classification and characterisation of these algae have been in constant flux. In light of these ongoing changes, the aim of this paper was to reconcile the most recent publications with previous consolidated records to produce the most up-to-date keys to the non-geniculate coralline red algae of South Africa. As a consequence of ongoing taxonomic changes and additional, more focused collections, currently 45 species of non-geniculate coralline red algae, belonging to three orders (Corallinales, Hapalidiales, Sporolithales), three families (Corallinaceae, Hapalidiaceae, Sporolithaceae), seven subfamilies (Choreonematoideae, Hydrolithoideae, Lithophyloideae, Mastophoroideae, Melobesioideae, Metagoniolithoideae, Neogoniolithoideae) and 18 genera are now recognised to occur along the South African coast. South Africa has representative species from more than half of the currently recognised extant genera of non-geniculate coralline red algae, with the order Corallinales best represented. Nearly one in four species are endemic to the South African coastline and nearly one in three species are endemic to the region. Recent molecular evidence has pointed to a large number of cryptic species, suggesting that the true diversity for South Africa is substantially greater than what is currently recognised based solely on morphology and anatomy. [ABSTRACT FROM AUTHOR]

Abstract: Working for Water forms part of the Expanded Public Works Programme of the South African Government, aimed at the sustainable management of natural resources through the control and management of invasive alien plants while enhancing socio-economic empowerment in South Africa. The programme''s name was taken from one of the original motivations: namely, reducing the impacts of invasive alien trees on water resources. A number of studies have looked at the potential impacts of the programme but only one or two have used actual management data to quantify its costs and benefits. This paper is the first, in hopefully a series of papers, on the costs and impacts of the programme over recent years. The paper focuses on the extent, costs and impacts of clearing invasive alien plants from riparian areas. Data were extracted from the Working for Water Information Management System (WIMS) and analysed to assess clearing costs and estimated impacts of clearance on water resources. Some of the most significant findings of the study again illustrate the need to treat invasions as early as possible. Very scattered (1–5%) invasions of selected species for example were between 3 and 25 times cheaper to clear than closed canopy stands (75–100%). On the other hand, unit reference values, used to compare clearing operations in terms of cost efficiency in generating extra water yield, were much higher for low levels of invasion than denser invasions, to the extent that the former''s viability could be questioned by the uninformed. However, this was only assessed in terms of extra water generated and not in terms of volumes of water secured, as invasive alien plants spread and become denser if not actively controlled. If left unchecked, water losses increase, which makes the clearing of light infestations much more viable. Overall, it is estimated that around 7% of riparian invasions have been cleared, resulting in significant yield increases. The increased estimated yield of 34.4 million m3 is about 42% of the yield of the new Berg River Scheme in the Western Cape (81 million m3). The investment in clearing species known for excessive water use from riparian areas, at a cost of R116 million, was found to be a very good investment. However, it is important to note that the clearing of invasive alien plants will seldom result in the total elimination of shortfalls in water supply and should be seen as part of a package of water resource options to optimize supply, aimed at minimizing wastage of water. [Copyright &y& Elsevier]

John Acocks' ideas on the recent and future changes of vegetation in South Africa occupy an important conceptual position in the first and subsequent editions of Veld Types of South Africa. Arguably the most prominent idea embodied in his discussion of vegetation changes is the hypothesis that various Karoo veld types were expanding eastwards and northwards into areas that would otherwise be occupied by grassland, and that this process was a direct result of mismanagement of the semi-arid rangelands. The invasion of Karoo vegetation amounts to a systematic consideration in South Africa of what would ultimately become known as desertification. This paper examines Acocks' interpretation of the vegetation changes associated with expanding Karoo and desert veld types and his evidence that this was indeed occurring. It places the apparent degradation into an appropriate historical context in relation to the evolving views of other South African and international scientists. The paper shows how Acocks' understanding of vegetation dynamics influenced agricultural policy, both immediately following publication of Veld Types and subsequently. Finally, a critique of the spreading Karoo hypothesis is developed in relation to current theory on desertification and its implications for management of the semi-arid rangelands of South Africa today. [ABSTRACT FROM AUTHOR]

Knowledge and understanding of wetland vegetation is an important component of sound wetland ecosystem management as vegetation represents a link between biota and ecosystem processes. In this paper, the saline wetlands of the arid inland regions of South Africa are discussed. Even though these wetlands contain water only occasionally they are among the largest wetland ecosystems in the country and their ecosystem processes are mostly determined by hydrological processes and particularly clay and salt deposition. These wetlands are dominated by three different groups of plants: salt-tolerant lawn grasses, sedges (occasionally) or halophytic shrubs. A subset of data from the South African National Wetland Vegetation Database, representing these vegetation types was used for analysis by means of clustering and ordination techniques. Twenty-nine saline wetland communities are described and these are further summarized into 15 community groups. Of the environmental variables used to explain the variation in the vegetation patterns, wetness appears to have the most important effect as it is also negatively correlated with electrical conductivity. Among the cations, it is sodium that has the greatest influence on species composition. Most of the types of saline wetlands are restricted to the Northern Cape and Free State Provinces, but plots with salt-tolerant grasses are found in all provinces except Gauteng. [ABSTRACT FROM AUTHOR]

This paper describes grass lawn wetlands, which are wetlands subjected to dynamic conditions, particularly highly fluctuating water tables that regularly drop deep below the ground surface. This occurs mostly in floodplain wetlands, as well as in wetlands in semi-arid regions or coastal plains. These wetlands are often dominated by short lawn grasses, particularly Cynodon dactylon , while other life forms, from taller tufted sedges to trees and shrubs, occur less frequently. A subset of data from a nationwide survey of wetland vegetation representing these grass lawn wetlands was selected for analysis using clustering and ordination techniques. Thirty-seven wetland communities are described and are further summarized into 13 community groups. Wetland communities on the coastal plains were associated with sandy soils whereas most of the other communities had a high clay fraction. Grass lawn wetlands are commonly found in a zone along the central, semi-arid part of the country and for this reason will likely play an important role in wetland monitoring in the long term. [ABSTRACT FROM AUTHOR]

In this paper, the wetland vegetation types of subtropical wetlands occurring in South Africa are discussed. The South African National Wetland Vegetation Database targeted the collation of all available wetland vegetation data consisting of species composition, Braun-Blanquet cover-abundance data and the relevant environmental parameters. A subset of this database that represented subtropical wetlands, was used for analysis by means of clustering and ordination techniques. Forty-nine wetland communities are described and these are summarized into sixteen community groups. The most important factors that account for the variation among these wetlands are the soil clay percentage and associated soil electrical conductivity. Some communities are associated with peaty or sandy soils with a very low soil electrical conductivity on the coastal plain while others that occur more in loamy soils with a high soil electrical conductivity are associated with drainage channels, at the foothills of mountains or the escarpment. A specific group of wetlands is associated with nutrient-poor substrates of the Msikaba group Sandstones in Pondoland or on coastal sands of Maputaland. Subtropical wetlands are particularly vulnerable to degradation due to cultivation as they are found in some of the most densely inhabited rural areas of South Africa. [ABSTRACT FROM AUTHOR]

This paper aims to characterise and describe the species composition of serpentine sites of the Barberton Greenstone Belt as compared to surrounding non-serpentine areas. A floristic analysis of seven serpentine (serpentinite) outcrops of the Barberton Greenstone Belt, in the eastern part of South Africa, recorded 744 species and subspecies, 319 genera and 94 families. 18 taxa remain undescribed. The Barberton Greenstone Belt flora includes 32 taxa endemic to serpentine soils and six taxa considered to be hyperaccumulators of nickel. The taxa considered to be endemic to serpentine outcrops make up 39% of the number of endemics found within the Barberton Centre of Endemism. The serpentine vegetation is characterised by fewer trees than the surrounding vegetation and the dominance of grass species such as Themeda triandra , Heteropogon contortus and Loudetia simplex . The species composition of each outcrop is relatively unique with only about 30% of species shared between any pair of outcrops. The flora of the serpentine outcrops of the Barberton Greenstone Belt is found to be different to the surrounding non-serpentine vegetation in terms of number of species per family, the ratios of dicotyledons to monocotyledons and familial composition. [ABSTRACT FROM AUTHOR]

Abstract: The exceptionally high plant diversity in the Cape region of southern Africa continues to attract considerable attention. In a recent paper Linder et al. (2010) concluded that diversification has been promoted by the physical complexity of the Cape environment and by certain biotic interactions, such as those between bees and flowering plants. Although these authors acknowledge the potential role of seed dispersal by ants, they suggested that there were no tests which would demonstrate whether rates of diversification were higher in myrmecochorous lineages versus those with other biotic or abiotic dispersal mechanisms. Here we argue that a set of recent papers by Dunn et al. (2007) and Lengyel et al. (2009, 2010) provide compelling evidence that myrmecochory may have resulted in a doubling of plant diversification, largely due to the greater likelihood of genetic isolation and also of the increased survival rate of plants possessing this dispersal mode. Here, we suggest that myrmecochory, which may be favoured in low nutrient soils, could be a key contributor to the high floristic biodiversity in the Cape region, as well as in other old, climatically stable landscapes such as those of southwest Australia. [Copyright &y& Elsevier]

Abstract: This paper presents a hierarchical system of forest communities of Mpumalanga Province (South Africa) compatible with the existing South African National Forest Classification (NFC). It describes and interprets floristic and physiognomic differences between the communities and the relevant higher-rank vegetation unit. A total of 434 relevés (rectangular plots, each 0.04ha; listing all species in the plots in Braun-Blanquet cover-abundance scale), sharing 619 species, served as the basis of the classification. The data were classified using the Flexible beta clustering (β=−0.25) in combination with the Bray–Curtis similarity measure. The proposed forest subtypes are described in terms of dominant plant families and genera, growth forms, seasonality or leaf retention characteristics, and the proportion of forest dependent species. Fourteen forest subtypes are distinguished within three national forest types, with no subtypes being recognised within the Lowveld Riverine Forest Type. We propose that the Wakkerstroom Midlands Forest Subtype be embedded within the Northern Highveld Forest Type, and not the Low Escarpment Mistbelt Forest Type as is currently recognised in the NFC. A total of 125 plant families and 375 genera were identified to occur in the Mpumalanga forests, with the most abundant species per family being Rubiaceae, Fabaceae, Celastraceae, Orchidaceae, Euphorbiaceae and Aspleniaceae. 76% of all forest plant species were obligate forest species and 80% of all tree cover is evergreen. [Copyright &y& Elsevier]

Abstract: Sixty-three percent of the world''s cycad taxa are threatened with extinction. In South Africa, 25 of the 38 indigenous species are categorised as Threatened on the IUCN Red List, primarily due to illegal collecting. Three of the country''s Encephalartos species are already Extinct in the Wild, while 10 Critically Endangered endemic Encephalartos species are undergoing rapid local extirpations across their ranges. Nearly two-thirds of South Africa''s Encephalartos species are used for traditional medicine, some of which are sold in traditional medicine markets in the form of bark strips and stem fragments. The leafless Encephalartos stems encountered in the medicinal and horticultural trades are generally difficult to identify to species and, since species identification of South African Encephalartos using DNA barcoding is not yet feasible, alternative methods of identification are required. To determine the identity of the species sold in South Africa''s two largest traditional medicine markets in KwaZulu-Natal (KZN) and Gauteng, surveys were conducted in the Warwick and Faraday markets respectively. Stem fragment samples purchased from the vendors in the markets were identified to species using stem and leaf base morphological characters in tandem with harvesting locality records. Six KZN Encephalartos species were successfully identified viz. E. ferox, E. ghellinckii, E. natalensis, E. ngoynaus, E. senticusos and E. villosus. Photographs of stem fragments and leaf bases of each species are presented here with supplementary quantitative and descriptive stem anatomical data. This paper therefore presents an identification guide to assist researchers and law enforcement officers in the identification of Encephalartos species unlawfully harvested for the traditional medicine and horticultural trades. The guide is thus also useful in the emerging discipline of wildlife forensics, and offers a unique approach to determining difficult-to-identify Encephalartos stem material. [Copyright &y& Elsevier]

Abstract: Arctotis sect. Anomalae was originally circumscribed to include three annual species (A. dregei, A. setosa and A. sulcocarpa) endemic to South Africa. Subsequently, discrimination of A. dregei and A. sulcocarpa became confused and application of the names has varied. In this paper, the circumscription of the two species is clarified and lectotypes designated for both names. The identity of A. setosa is less certain. The type of A. setosa, likely to have been lodged in the Berlin-Dahlem herbarium, has not been traced and no duplicates have been located. However, from the description and illustration of an achene in the original publication, A. setosa was almost certainly based on an element of the Arctotheca calendula species complex and is excluded from Arctotis sect. Anomalae. During examination of herbarium specimens in the course of this study, it became clear that an additional, previously unnamed species belonging to A. sect. Anomalae should be recognized, which is formally described here. The new species, Arctotis dimorphocarpa, differs from A. dregei and A. sulcocarpa in possessing pistillate ray florets, but is placed in sect. Anomalae based on the correspondence in vegetative, style and achene morphology and filament ornamentation. It is unusual among Arctotidinae in possessing heteromorphic ray and disc floret achenes. Additional information on the distribution and conservation status of A. dimorphocarpa and A. sulcocarpa is needed. [ABSTRACT FROM AUTHOR]

Abstract: Quality assessment of natural raw materials and derived consumer products is often done using conventional analytical techniques such as liquid and gas chromatography which are expensive and time consuming. This paper reports on the use of vibrational spectroscopy techniques as possible alternatives for the rapid and inexpensive assessment of the quality of ‘buchu oil’ obtained from two South African species; Agathosma betulina and Agathosma crenulata belonging to the Rutaceae family. Samples of A. betulina (55) and A. crenulata (16) were collected from different natural localities and cultivation sites in South Africa. The essential oil was obtained by hydrodistillation and scanned on Near infrared (NIR), mid infrared (MIR) and Raman spectrometers. The spectral data obtained was processed using chemometric techniques and orthogonal partial least squares discriminant analysis (OPLS-DA) was used to clearly differentiate between A. betulina and A. crenulata. The OPLS-DA technique also proved to be a useful tool to identify wave regions that contain biomarkers (peaks) that contributed to the separation of the two species. The three spectroscopy techniques were also evaluated for their ability to accurately predict the percentage composition of seven major compounds that occur in A. betulina ‘buchu’ oil. Using GC–MS reference data, calibration models were developed for the MIR, NIR and Raman spectral data to predict/profile the major compounds in ‘buchu oil’. A comparison of the three spectroscopy techniques showed that MIR together with PLS algorithms produced the best model (R2X=0.96; R2Y=0.88 and Q2Ycum=0.85) for the quantification of six of the seven major oil constituents. The MIR model showed high predictive power for pseudo-diosphenol (R2 =0.97), isomenthone (R2 =0.97), menthone (R2 =0.90), limonene (R2 =0.91), pulegone (R2 =0.96) and diosphenol (R2 =0.85). These results illustrate the potential of MIR spectroscopy as a rapid and inexpensive alternative to predict the major compounds in buchu oil. [Copyright &y& Elsevier]

Abstract: This paper evaluates the history of fire management in the Bontebok National Park (3435ha) over a period of almost four decades. A GIS database was compiled of all fires between 1972 and 2009 and the fire regime was analysed in terms of the frequency, season, size and cause of fires. Since the early 1970s, short interval burning was implemented to promote grazing for bontebok, but from 2004 the fire interval was lengthened to favour plant species diversity, an increasingly urgent conservation priority for the park. In total, 43 fires were recorded, ranging in size from 9 to 1007ha, collectively spanning 14013ha. The majority of fires were large (100–500ha), with fires of >100ha accounting for 96% of the area burnt. The overall mean fire return period (FRP) for the park was 7.2years, which is short judged by fynbos standards. FRPs under the old and new management regimes were 6.7 and 10.9years respectively. Under the old regime, FRPs in renosterveld and fynbos were 5.8 and 8.0years respectively. Large parts of the park repeatedly experienced fires at immature vegetation ages resulting in the elimination of slow-maturing seed-regenerating plant species such as Protea repens. Post-fire age distribution was highly skewed towards young vegetation, with 75% of fire-prone vegetation burning at post-fire ages of ≤7years, and <10% of fire-prone vegetation surviving beyond 10years of age. Prescribed and accidental fires respectively accounted for 70% and 30% of the total area burnt. Prescribed burning was mostly done in March–April, and only 8% of the total area burnt, burnt outside of the ecologically acceptable fire season. This study identified areas which have been subject to ecologically appropriate and inappropriate fire return intervals, providing a basis for informed future management and research. [Copyright &y& Elsevier]

Abstract: Three new species of the genus Trachyandra are described, T. hantamensis Boatwr. & J.C.Manning, T. kamiesbergensis Boatwr. & J.C.Manning and T. sanguinorhiza Boatwr. & J.C.Manning. These species form part of a group of morphologically similar species referred to here as the T. thyrsoidea group and are distinguished by their generally small stature, filiform leaves (except for T. tortilis), and simple or shortly branched racemes of patent flowers with maculate tepals. Many of the species in the group have roots that contain abundant anthraquinones, visible as a red substance below the outer skin of the roots, and which is soluble in alcohol, thus often staining herbarium papers purple. A synopsis of the eight species that comprise the T. thyrsoidea group is presented, with maps of each species and illustrations of those described as new. [Copyright &y& Elsevier]

Abstract: Oxalis L. is the largest and most diverse genus in the family Oxalidaceae. Within southern Africa, Oxalis is represented by ca. 270 taxa, the majority occurring in the Cape Region. Although many of the species are widespread, ca. 25% are considered rare. The aim of this paper is to assess the degree of genetic differentiation between two rare and highly localized species (Oxalis hygrophila Dreyer and Oxalis oligophylla Salter) and the more widespread Oxalis tomentosa L.f. For comparative purposes, we also include Oxalis purpurea L., one of the most widely distributed species in South Africa. Chloroplast sequences of the trnH/psbA spacer revealed low genetic diversity for O. oligophylla and O. tomentosa compared to the widespread O. purpurea. High genetic diversity in O. purpurea might, in combination with other ecological and reproductive factors, account for the success of this species. In contrast, low variation might contribute to rarity in O. oligophylla and ultimately ground O. tomentosa to become rare. The latter two species were not monophyletic with a shared haplotype. Coalescent modelling revealed low levels of gene flow (<1 migrant per generation) between them and we argue that the genetic pattern is the result of the retention of ancestral polymorphism following a recent divergence. [Copyright &y& Elsevier]

Abstract: This paper addresses phenotypic variation among Paterson''s Curse (Echium plantagineum L.) populations in four different habitat types (tar road verges, dirt road verges, abandoned fields and natural areas) in the Western Cape region of South Africa. The species showed significant differences in plant height, seed size and seed weight with varying habitats. The reproductive index (Ri), comprising a ratio of total number of seeds to the height of the plant, demonstrated the plastic behavior of E. plantagineum in the various habitats. Results indicate that plastic responses to different habitat types contribute to E. plantagineum invasiveness, allowing range expansion and establishment through production of lighter and heavier seeds, respectively. [Copyright &y& Elsevier]

Abstract: Non-geniculate coralline red algae are common in all of the world''s oceans, where they often occupy close to 100% of the primary rocky substratum. The South African rocky subtidal and intertidal habitats in particular, are rich in diversity and abundance of non-geniculate coralline red algae. Despite their ubiquity, they are a poorly known and poorly understood group of marine organisms. Few scattered records of non-geniculate coralline red algae were published prior to 1993, but these should be treated with caution since many taxa have undergone major taxonomic review since then. Also, generic names such as Lithophyllum and Lithothamnion were loosely used by many authors for a host of different non-geniculate coralline algae. A series of taxonomic studies, based mainly on the Western Cape Province of South Africa, published particularly between 1993 and 2000, has significantly extended our knowledge of these algae from southern Africa. References to these latter papers and the older records are now gathered here and a list of the well delimited families (3), subfamilies (4), genera (17) and species (43) are presented. A catalogue with keys to the various taxonomic categories is also provided. A marked reduction in the number of real taxa has been found largely because many earlier recorded taxa have been reduced to synonymy, or have not been verified, or examined in a modern context and so their placement is considered dubious, particularly because the Corallinales have undergone major taxonomic revisions in recent years. [Copyright &y& Elsevier]

Presents several abstracts of papers and posters presented at the 31st Annual Congress of the South African Association of Botanists on January 10-14, 2005. "Reactive oxygen species often lie at the heart of plant stress," by C.H. Borman; "Defense against aphids in crop plants," by G. Delp et al.; "Sink: source transition in relation to plastochron index in Pisum sativum," by O.E. Ade-Ademilua and C.E.J. Botha.

Indigenous leafy vegetables can play an important part in alleviating hunger and malnutrition in sub-Saharan Africa, but they are often neglected in research. They are important sources of micronutrients including vitamins A and C, iron and other nutrients and are sometimes better nutritional sources than the modern vegetables. The leaves of cultivated plants, such as pumpkins, melons and cowpeas are used as a leafy vegetable, as well as leaves from wild and weedy species from farmers' fields and the veld. These wild and weedy species include amaranth species, Corchorus species and Cleome gynandra amongst others, and all have the potential to be cultivated. The harvested leafy vegetables are perishable, but can be processed and preserved by partial cooking, blanching or drying. This paper provides ecogeographical information and some botanical descriptions; we discuss the importance of leafy vegetables in food security, the monetary value of some of these crops and report on some of the research carried out at ARC-Roodeplaat (Pretoria), South Africa. [ABSTRACT FROM AUTHOR]

Following a recent announcement by the Minister of Arts, Culture, Science and Technology, Dr B.S. Ngubane, that 'We will support only the top general science journal and we will provide medium-term seed funding for the development of one or two journals in niche research publication areas', an in-depth analysis of the current state of funding of South African Journal of Botany and of the mechanisms according to which it is produced became necessary. This paper reports on the results of this analysis. Proposals are made that will ensure the continued publication of the Journal.Keywords: Bureau for Scientific Publications, finances, publication and production mechanisms, South African Journal of Botany.[sup*]To whom correspondence should be addressed. [ABSTRACT FROM AUTHOR]

Received 2 July 1999; revised 5 October 1999The aim of this paper is to identify, classify and describe plant communities on abandoned, formerly cultivated, old fields in the former Transkei (Eastern Cape Province) and to derive hypothetical succession pathways. Forty two releves, made in representative areas with abundant old-field lots, were classified and ordinated using standard methods of numerical vegetation data analysis. Three new associations were recognised, namely the Richardio brasiliensis-Eragrostietum planae, the Trichoneuro grandiglumis-Aristidetum congestae and the Tageto minutae-Cynodontetum dactyli. Within the Tageto minutae-Cynodontetum dactyli, two new sub-associations were recognised, namely cyperetosum esculenti and typicum. The most important coenocline spanning the young Tageto minutae-Cynodontetum dactyli and the old Richardio brasiliensis-Eragrostietum planae, correlated with the age of old-fields. We postulate that this coenocline might represent the main succession trend within the mesic old fields in Transkei. The Trichoneuro grandiglumis-Aristidetum congestae characteristic of dry sandy soils does not participate in this cline.Keywords: abandoned land, associations, ordination, plant communities, succession syntaxa. [ABSTRACT FROM AUTHOR]

Received 17 December 1998; revised 17 September 1999The principle aim of this paper is to ascertain the relationship between plant biomass, vessel size and vessel frequency in relation to soil type and available water. Inherent within this primary determinant is an attempt to provide information on the mechanisms attributing to the high species diversity within the Fynbos Biome and the forces controlling the boundaries between communities. To achieve this objective two treatments tested fynbos and forest plants for the effects of available water and nutrients on xylem vessel morphology and plant biomass. In the watering treatment mean vessel diameters and vessel frequencies for Protea nitida and Cunonia capensis do not significantly differ between the wet and dry treatments. This suggests that neither Protea nitida nor Cunonia capensis are able to adapt vessel morphology to changes in available water. The results for the nutrient treatment show that for the two Protea species Protea neriifolia and Protea nitida there is no significant difference in vessel diameters and frequencies between the two soil types. These results suggest that fynbos and forest species are probably genetically adapted to the environments in which they live, as a result of which vessel morphology of these woody species lack the plasticity to adapt to changes in soil type and soil moisture. We propose that this is because soil type and water availability play important roles in maintaining boundaries between plant communities in the fynbos.Keywords: Fynbos, soil moisture, soil nutrients, vessel frequency, vessel diameter, Protea neriifolia, Protea repens, Protea nitida, Kiggelaria africana, Cunonia capensis. [ABSTRACT FROM AUTHOR]

Profiles Kenyan-born Chris H. Bornman, recipient of the 2003 South African Association of Botanists Gold Medal. Education and career background; Participation in international courses in plant biotechnology; Number of primary research papers published; Fellowships in Germany and Sweden; Work in Sweden for a biotechnology firm; Work with the United Nations Educational, Scientific & Cultural Organization.