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Identification guide to southern African grasses: an identification manual with keys, descriptions and distributions.

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This identification guide relies primarily on the use of keys and descriptive information to aid the use in identifying a grass species. It contains some of the best information needed to identify southern African grasses. Keys to grass genera and species are provided, and in some instances also keys to easily confused taxa. For each species, a combination of useful characters is provided, and where applicable, line drawings of the spikelet or parts thereof accompany the identification keys. Species descriptions and distribution maps are hugely important and add to the identification of grasses.
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... This species differed, at once, from all the other known congeners in India with its fragile rhachis disarticulating into spiculated segments-a character found in Afro-Arabian species. On perusal of literature and articles available on this genus from India and Africa, such as, (Hooker 1897, Hutchinson & Dalziel 1972, Phillips 1975, Clayton et al. 2006, Fish et al. 2015 it became evident that it shared many similarities with a few, chiefly Afro-Arabian, species viz. O. minimum, O. capense and O. aristatum. ...
... The detailed comparative study in all the species of this genus in the world has been provided in Table 1. *The information has been taken from (Hooker 1897, Hutchinson & Dalziel 1972, Phillips 1975, Clayton et al. 2006, Fish et al. 2015. The three Indian species have been studied at BLAT and the observations are also included in this study. ...
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Oropetium almeidanum, a new species has been described from Thar Desert, Jaisalmer, Rajasthan based on the specimens collected recently from Jaisalmer and a specimen present in the Blatter Herbarium (BLAT). The new grass is allied to three African species viz.,O. minimum, O. capense and O. aristatum. Detailed description, photo plate and illustration of a new species along with a brief discussion on its close affinities are given. Key to distinguish all the species of Oropetium in the world along with the table of their detailed morphological comparison is provided to facilitate their proper identification.
... These two species are common in South African grasslands and are frequently used for restoration, but are different in their morphology and ecology. For example, E. curvula is a relatively shadeintolerant densely tufted pioneer grass, producing large numbers of small seeds with a high germination potential, while M. maximus is a shade-tolerant broad-leaved late seral grass, with a creeping rhizome, producing fewer, larger seeds with lower viability (Meredith 1955;Adkins et al. 2011;Fish et al. 2015). These two species can be used to predict the response of other South African species that are useful for restoration. ...
... Even though we did not measure these factors (soil moisture, temperature and light), it is fair to assume that vetiver tufts altered these factors, because emergence in native grasses was enhanced. Megathyrsus maximus is a shade-tolerant grass; hence its seeds could be adapted to germinate in relatively shady, moist areas (Fish et al. 2015;Van Oudtshoorn 2016). This might explain why the presence of a neighbouring plant boosted seedling emergence. ...
Article
Species-rich grasslands provide important ecosystem services, and in South Africa, approximately 40% of these grasslands are degraded. Vetiver grass (from India) is often used during rehabilitation efforts to restore soil function without a thorough understanding of the potential negative ecological impacts. Hence, a study was initiated to investigate vetiver’s ecological impacts during grassland rehabilitation. Firstly, a field survey was conducted using a contiguous quadrat method to evaluate the extent of grass secondary succession in these rehabilitated sites. Secondly, the effect of vetiver competition and seed sowing method on the recruitment of two native grasses (Eragrostis curvula and Megathyrsus maximus) was examined using pot trials. The field survey results showed no evidence of grass secondary succession, but rather the abundance of bare ground around vetiver, and a marked increase in grass species richness with increasing distance from planted vetiver. Subsequently, in the pot trial, vetiver facilitated emergence in both native grasses, and soil surface sowing of indigenous grass seeds showed greater emergence than other sowing methods. However, vetiver inhibited native grass seedling establishment, even when root competition was excluded. This study suggests that areas rehabilitated using vetiver are unlikely to become productive grasslands with good grazing, because vetiver inhibits colonisation by native grasses.
... At least 15 species are known from a single collection; 18 species have not been found in the field in spite of dedicated searches ; Sartidia perrieri and Chasechloa egregia are likely extinct (Vorontsova et al. 2015;Silva et al. 2017). Malagasy grasses are poorly known compared to those in neighboring areas where complete treatments are available: Flora Zambesiaca (Launert 1971;Clayton 1989;Cope 1999Cope , 2002, southern African grasses (Fish et al. 2015), and Flora of the Mascarenes (Renvoize 2019). ...
... In the same visit, another locality ( Fig. 4) was discovered where this species was flourishing on a slippery basalt slope in a distinct spatially segregated colonies. After critical study of relevant literature (Roxburgh 1832, Hackel 1889, Hooker 1897, Cooke 1908, Blatter & McCann 1928, 1935, Bor 1940, Fischer 1957, Bor 1960, Cope 1982, Mistry 1988, Sreekumar & Nair 1991, Lakshminarasimhan 1996, Sur 2001, Clayton et al. 2005, Singh & Rao 2008, Srivastav & Nair 2010, Simon & Alfonso 2011, Potdar et al. 2012, Kabeer & Nair 2009, Fish et al. 2015, Lakshminarasimhan et al. 2019, Chorghe & Prasanna 2021) the species could not be ascertained with any known species in the genus, chiefly because of the characters such as: dioecy, four larger stamens, 1-flowered sessile spikelet and lodicules lacking in the upper floret of female plant. Thus, we described it as a new species after extensive literature survey and communication with numerous experts in the field across the globe. ...
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Ischaemum dioecum, a new strange species from Northern Western Ghats, Maharashtra, India is described and illustrated. The most spectacular and unusual feature of the species is its dioecious breeding system i.e. male and female plants are sexually separate entities, which is being documented first time in the tribe Andropogoneae. Other distinguishing features are such as: sessile spikelets 1-flowered (only upper floret developed), palea bi-dentate with an arista from the sinus and pedicelled spikelet reduced or absent; stamens four with unusually filiform and elongated filaments, ca. 15 mm long; peduncle of male plants glandular and with tubercle-based bristles; style and stigma extraordinarily long each may be up to 14 mm long and pedicel 1/2-4/5 of the sessile spikelet. A table of morphological comparison and detailed discussion with allied species from Africa, India and Australia is given along with the keys to close genera. A detailed discussion on the similar case of dioecism in grasses; habitat characteristics, distribution of the populations and inter-specific interaction, adaptation and morphological affinities of I. dioecum is discussed with African, Indian and Australian taxa. It is apparently a narrow endemic species. Based on IUCN Red List Categories and Criteria, the species is assessed here as Critically Endangered (CR).
... Within the quadrat, the overall vegetation cover per quadrat was estimated (using a modified Braun-Blanquet scale; . Plant species recorded in each quadrat sample were identified using existing knowledge, different plant field guides (e.g., Van Wyk and Van Wyk, 2013;Fish et al., 2015;Joffe and Oberholzer, 2012) and a South African database (www.plantzafrica.com). When positive field identification was not possible, plant species were assigned a nickname (e.g., unknown1), and both physical samples (e.g., leaves, flowers) and digital records were collected for further identification. ...
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The conservation gardens under South African Biodiversity Institute (SANBI) preserve biodiversity areas with unique and threatened vegetation types including national priority Critical Biodiversity Areas (CBA’s). The mandate of SANBI is to champion the exploration, conservation, appreciation, and enjoyment of South Africa’s exceptionally rich biodiversity for all people. Since the SANBI mandate emphasises sustainable biodiversity conservation, however, there were no studies that have quantitatively appraised the biodiversity conservation value and natural phenomena dynamics over time for different SANBI conservation gardens. This study determined the dynamics of the vegetation cover over a 30-year period (1987-2017) and potential environmental drivers of change in Free State National Botanical Garden (FSNBG). The FSNBG is located in the broader southern African grassland biome that is under huge conservation threats in South Africa. The FSNBG preserved national priority for biodiversity conservation (CBA1) in South Africa: the “Bloemfontein Karroid Shrubland”. The study applied the remote sensing technology and Geographical Information System (GIS) imagery to analyse the spatial vegetation cover changes that occurred over 30-years using 10 year’s intervals. Overall study results show that vegetation cover of the study area significantly increased (in term of woody biomass) over the 30-year period, partly attributed to the combination of factors, which include severe droughts and the rise of CO2 concentrations in the atmosphere. In addition, it was possible that absence of the biophysical disturbance such as fire and browsers in the natural vegetation to suppressed wood species has encourage encroachment of woody cover species. Using Normalized Difference Vegetation Index (NDVI) approach, the vegetation of FNSBG was divided into four categories, namely: Dense vegetation, Moderate vegetation, Sparse vegetation, and open soil. Overall, the sparse vegetation cover significantly decreased over time (R2 = - 0.29). Similarly, the moderate vegetation cover increased by 25.1 ha while dense vegetation also increased by 8.6 ha. However, the bare soil cover was found to be relatively consistent over the 30-year period. Since the use of the remote sensing and GIS imagery could not clearly validate the current ecological status of CBA1 vegetation type, the manual field sampling approach was used looking into documenting the typical plant species provided by Mucina and Rutherford (2006); and measuring the vegetation cover. Vegetation cover of CBA1 was relatively high (i.e., 79.6 ± 15.9%); and this was above the minimum threshold of 60% habitat intactness reported to represent the habitat functionality that is normal although overall integrity is reduced. The existence of CBA1 vegetation type was supported by a record of 27 plant species out of 77 species documented as typical in the key descriptions provided by Mucina and Rutherford (2006). Major conservation threats entailed of 27 invasive alien plant species, human settlement encroachment have reduced the ecological buffer zone of FSNBG by 18% (119.07 ha) in the past 18 year; and 10 pests and pathogens that were interspersed in different vegetation patches of the study site. The observed changes suggested a need for regular vegetation monitoring of CBA1 vegetation type to manage the prevailing conservation threats that could have impact to ecological integrity. Animal-plant mutualisms are important for the maintenance of both animal and plant population since both participating partners’ benefit. The phenology of seed dispersal is critical to the successful recruitment of species since dispersed seeds require conducive conditions for germination. Having noted the increasing bush encroachment in FSNBG in the past 30 years, the study also investigated the seed dispersal phenology and the potential influencing factors for the encroaching tree/shrub species of FSNBG focusing on biotic interaction of flesh fruits resource foraged by birds as study model. During fieldwork sampling for the seed deposited by birds in the 17 roosting sites, I collected a total of 22 161 seeds belonging to 14 native and non-native tree/shrub species. It was found that black and red fruits were more preferred by birds since most of the dispersed tree/shrub species had those colours and attracted 22 resident and colonial migratory frugivorous birds. I found that 80% of the bird-ingested and dispersed seeds of many tree/shrub species were collected between March and July. Two species: Ehreta rigida and Searsia lancea, displayed relatively short fruiting peak times between August and December when other fruits were scarce. Whereas the observed two fruiting patterns could reduce the competition for seed dispersal services between two groups of tree/shrub species, the resident and wintering birds are also likely to benefit substance in food resources. In addition, it was found that frugivorous birds adapt to localised foraging patterns and to limited fruit diversity. It was concluded that the highly preferred tree/shrub species are likely drivers of the reported bush encroachment in FSNBG. Frugivorous birds disperse seed away from parent plant to new microsites that have relatively lower competition for the resources, and ingested seeds get scarified during feeding on fruits and ingestion by birds. Therefore, the study also investigated whether bird-dispersed seeds benefit from improved germination after their passage through the bird’s gut and the potential impact of seed density on competition at the microsites. On the germination trail results of bird-ingested seeds versus manual depulped seeds, Ziziphus mucronata displayed the highest germination rate of all trees/shrubs yet frugivorous birds did not improve its seed germination. However, only S. lancea seeds had significantly high seed germination after passage through the avian digestive tract. The test experiments for seed competition during germination at the microsite showed that only Z. mucronata and Olea europaea subsp. africana displayed significant positive performance with increasing seed density. The study concluded that the tree/shrubs species with high germination could account for the observed bush encroachment in FSNBG. It was recommended that adaptive conservation management plan of FSNBG should include monitoring and prioritised bush encroachment control of those species.
... Some invasive alien grasses that appear in large wilderness areas, such as the Drakensberg in South Africa, may appear in this category; an example is the grass Deschampsia cespitosa (L.) P.Beauv. 39 Even so, these species may impact such a wetland to such an extent that its functioning within the catchment as a whole is compromised and eventually seeds or clonal fragments can spread further downstream. ...
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An inventory of wetland vegetation across the country generated a list of the most common invasive alien plants across South Africa. Many of the plants on that list do not correspond with the priorities in the programmes for alien control across the country, as they are not listed on a government produced list that guides the priorities for alien control. We explore the reasons for this situation. We argue that because wetlands are such important parts of the landscape, invasive aliens in wetlands are of special concern, and there should be more alignment between alien control programmes and wetland rehabilitation programmes. This alignment starts by considering the full number of species that form a threat to wetland habitats, but also considers which pesticides to use, erosion and recolonisation in wetlands, planting indigenous vegetation after aliens have been removed, and strategising by working from upstream to downstream. Existing alien control programmes for specific grasses (some relatively new to the country and in the phase of early detection) and floating aquatic plants may guide how to tackle the invasions of grasses and forbs that have been established in South African wetlands for an extended period of time. Significance: • Wetlands have a distinct set of alien invasive plants that affect their ecology and functioning and many of these plants are not listed as priorities in alien control programmes. • Many restoration projects have an element of removing invasive plants and revegetating. Wetland restoration and alien control need to be integrated to preserve water resources.
... However, further host range testing found attack on Austroderia fulvida (Buchanan) NP Barker et HP Linder in one replicate, which has halted further research on the planthopper until wild populations of C. selloana closely related to New Zealand populations can be located in Chile. Given that no native Cortaderia or Austroderia species (the closest relatives of Cortaderia) occur in South Africa (Fish et al. 2015), this non-target attack by S. subandina is unlikely to render it insufficiently host specific for South Africa, and can be considered a promising candidate if the source population/s of South African C. selloana can be located in South America. ...
Article
Historically, invasive alien grasses have not been considered a major threat in South Africa, and as a result, very few resources are allocated to their management. However, there is an increasing awareness of the severe environmental and socio-economic impacts of invasive grasses and the need for appropriate management options for their control. South Africa has a long history of successfully implementing weed biological control (biocontrol) to manage invasive alien plants, however much like the rest of the world, invasive grasses do not feature prominently as targets for biocontrol. The implementation and early indicators of success of the few grass biocontrol programmes globally and the finding that grasses can be suitable targets, suggests that biocontrol could start to play an important role in managing invasive alien grasses in South Africa. In this paper, we evaluated the prospects for implementing novel grass biocontrol projects over the next ten years against 48 grasses that have been determined to represent the highest risk based on their current environmental and economic impacts. The grasses were ranked in order of priority using the Biological Control Target Selection system. Five grasses were prioritised Arundo donax L., Cortaderia jubata (Lem.) Stapf, Cortaderia selloana (Schult & Schult) Asch. & Graebn., Nassella trichotoma (Hack. ex Arech.), and Glyceria maxima (Hartm.) Holmb., based on attributes that make them suitable biocontrol targets. Arundo donax has already been the target of a biocontrol programme in South Africa. We reviewed the progress made towards the biocontrol of this species and discuss how this programme could be developed going forward. Moreover, we outline how biocontrol could be implemented to manage the remaining four high-priority targets. While biocontrol of grasses is not without its challenges (e.g. unresolved taxonomies, conflicts of interest and a lack of supporting legislation), South Africa has an opportunity to learn from existing global research and begin to invest in biocontrol of high-priority species that are in most need of control.
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The genus Phragmites includes taxa that are very difficult to distinguish macroscopically, and even genetically. To better discriminate these taxa, microscopic traits, such as the epidermis of floral bracts and leaves, and leaf anatomy, were investigated. In the Old World, four distinct giant reeds species (> 3 m) were delineated: two tropical species, P. karka and P. mauritianus, and two Mediterranean species, P. altissimus and P. frutescens. Previously included within P. australis sensu lato, the rehabilitation of P. altissimus and P. frutescens is supported by relevant distinctive characteristics. Conversely, the small reeds (< 3 m) from temperate to cold regions form a distinct group. Although this group is still difficult to subdivide with epidermis traits, three taxa can be separated using leaf anatomy: both the Afro-European and the Australian-E. Asian P. australis sensu stricto, and P. japonicus. Using iodine green solution, we link our morphological analyses with previous genetic clustering, the green coloration of floral bracts and margin leaf teeth matches with the presence of nuclear waxy gene bands in P. frutescens and P. mauritianus (100 bp), and P. altissimus (200 bp), while P. karka, P. australis subsp. australis and P. japonicus have no coloration nor waxy band. While leaf anatomy features seem to be correlated with eco-climatic conditions, the epidermal traits delimited other clades. For leaf epidermis P. karka, P. mauritianus, and P. frutescens present the more ancestral characters, whereas P. australis, P. japonicus, and P. altissimus possess derived traits. Lastly, floral bract epidermis traits separate two divergent evolutionary lineages from the basal P. karka.
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We used a long-term herbivore removal experiment where paired exclosure–open treatments were established at the Mpala Research Centre, Laikipia, Kenya, in 1999 to examine changes in soil nitrogen (N) at nutrient-rich glades and adjacent nutrient-poor bushland sites after almost two decades of herbivore removal. Glades in this landscape are created by large inputs of dung and urine from previous long-term corralling of cattle in an otherwise nutrient-poor matrix of woodland (bushland). We predicted (1) a net gain of soil nutrients at bushland sites (that is, inputs of nutrients > losses) and (2) a net loss of soil nutrients at glade sites (that is, inputs of nutrients < losses) following herbivore exclusion. As expected, soil N increased (by 28% after 17 years) with herbivore removal, but remained largely unchanged in the presence of herbivores at low-nutrient bushland sites. However, contrary to our expectations, soil total N in nutrient-rich glades also increased (+ 18%) when herbivores were removed, but declined when grazed (− 11%). Although the underlying mechanisms are unclear, we suggest that increased N fixation by Acacia spp., combined with increased canopy cover and associated tree leaf litter, resulted in elevated soil N following browser removal in low-nutrient bushland sites, while grazer-induced increases in the rate of N transformations between organic and mineral forms resulted in a more “open” N cycle (as evidenced by higher N mineralization rates and foliar N), with increased potential for N loss in gaseous forms, in grazed nutrient-rich glade sites. Grazers and browsers thus appear to affect the N cycle and create and reinforce heterogeneity in unique ways.
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