Article

Satyrium liltvedianum : A newly discovered orchid species from the Kogelberg Mountains of the Cape Floristic Region (South Africa)

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  • University of KwaZulu-Natal, South Africa, Pietermaritzburg
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Abstract

Individuals of plant populations with traits which are inconsistent with any existing species description may represent intraspecific variants, products of hybridisation, or a novel species. To distinguish among these possibilities for a population of unusual Satyrium individuals from the Kogelberg Mountains in the Cape Floristic Region (CFR), morphological traits and floral scent were documented, and phylogenetic analyses implemented. Plants from the Kogelberg population were characterised by long-spurred white flowers and a bifid rostellum. Floral scent was dominated by the common floral monoterpene volatile β-linalool. Although these traits characterise several southern African members of the genus, DNA sequences from the nuclear and plastid genomes of an accession from the Kogelberg population were highly distinct from other Satyrium species. The Kogelberg accession occupied an isolated phylogenetic position within the ‘Satyrium clade’ and was not sister to any other species with similar traits. There was weak support for membership of a clade of species with which plants from the Kogelberg population share the possession of lateral sepals that project at a perpendicular angle to the median sepal, and cover the side of the labellum, and which also produce β-linalool as dominant scent compound. Given the congruence of phylogenetic relationships inferred from plastid and nuclear DNA sequences respectively, a hybrid status of the Kogelberg population was rejected. Based on these results, the new species, Satyrium liltvedianum, which is uniquely characterised by the size, shape and orientation of sepals and lateral petals, is described in this study. Other Satyrium species with similar floral traits are pollinated by crepuscular moths, which therefore can also be inferred for the new species. A dichotomous key to the white-flowered, long-spurred Satyrium species of South Africa is provided. The restricted distribution range, a typical phenomenon for many CFR plant species, in combination with the isolated phylogenetic position, suggests that S. liltvedianum represents a palaeoendemic species.

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... For instance, species can be morphologically similar, but phylogenetic analysis of these species with congeners can reveal whether this similarity is due to convergence or homology (e.g. van der Niet, 2017;Salazar et al., 2018). Furthermore, analysis of geographical distributions can shed light on the level at which taxa under dispute should be formally recognized; divergent allopatric populations may represent early stages of divergence and be recognized at the subspecies level (e.g. ...
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Superficial similarities among unrelated species are often a result of convergent evolution and can cause considerable taxonomic confusion. A case in point is Satyrium eurycalcaratum, described here as a new species, which has been confused with several other Satyrium spp. with similar long-spurred, white flowers. A phylogenetic analysis, based on molecular data, indicated that S. eurycalcaratum is not closely related to any of the species with which it has been previously confused. A comparative analysis of morphological characters in the seven South African Satyrium spp. with long-spurred, white flowers showed that each of these, including S. eurycalcaratum, is characterized by a unique combination of traits. Despite the similarity in pollination syndrome characters, such as spur length and flower colour, variation in rostellum structure was particularly pronounced and four distinctive forms were present. There was no phylogenetic signal in patterns of interspecific rostellum variation, as some closely related species had different rostella, whereas some distantly related species shared similar rostellum structures. We therefore conclude that the use of rostellum traits in conjunction with phylogenetic evidence can resolve species delimitations among orchid species that share the same pollination syndrome. © 2011 The Linnean Society of London, Botanical Journal of the Linnean Society, 2011, 166, 417–430.
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Plants are expected to emit floral scent when their pollinators are most active. In the case of long-tubed flowers specialised for pollination by crepuscular or nocturnal moths, scent emissions would be expected to peak during dawn. Although this classic idea has existed for decades, it has rarely been tested quantitatively. We investigated the timing of flower visitation, pollination and floral scent emissions in six long-spurred Satyrium species (Orchidaceae). We observed multiple evening visits by pollinaria-bearing moths on flowers of all study species, but rarely any diurnal visits. The assemblages of moth pollinators differed among Satyrium species, even those that co-flowered, and the lengths of moth tongues and floral nectar spurs were strongly correlated, suggesting that the available moth pollinator fauna is partitioned by floral traits. Pollinarium removal occurred more frequently during the night than during the day in four of the six species. Scent emission, however, was only significantly higher at dusk than midday in two species. Analysis of floral volatiles using gas chromatography coupled with mass spectrometry yielded 168 scent compounds, of which 112 were species-specific. The scent blends emitted by each species occupy discrete clusters in two-dimensional phenotype space, based on multivariate analysis. We conclude that these long-spurred Satyrium species are ecologically specialised for moth pollination, yet the timing of their scent emission is not closely correlated with moth pollination activity. Scent composition was also more variable than expected from a group of closely related plants sharing the same pollinator functional group. These findings reveal a need for greater understanding of mechanisms of scent production and their constraints, as well as the underlying reasons for divergent scent chemistry among closely related plants.
Article
Closely related species (e.g., sister taxa) often occupy very different ecological niches and can exhibit large differences in geographic distributions despite their shared evolutionary history. Budding speciation is one process that may partially explain how differences in niche and distribution characteristics may rapidly evolve. Budding speciation is the process through which new species form as initially small colonizing populations that acquire reproductive isolation. This mode of species formation predicts that, at the time of speciation, sister species should have highly asymmetrical distributions. We tested this hypothesis in North American monkeyflowers, a diverse clade with a robust phylogeny, using data on geographical ranges, climate, and plant community attributes. We found that recently diverged sister pairs have highly asymmetrical ranges and niche breadths, relative to older sister pairs. Additionally, we found that sister species occupy distinct environmental niche positions, and that 80% of sister species have completely or partially overlapping distributions (i.e., are broadly sympatric). Together, these results suggest that budding speciation has occurred frequently in Mimulus, that it has likely taken place both inside the range and on the range periphery, and that observed divergences in habitat and resource use could be associated with speciation in small populations. This article is protected by copyright. All rights reserved.
Article
Electroantennograms (EAGs) from field-collectedHyles lineata moths were recorded in response to 10 individual floral volatiles identified fromClarkia breweri (Onagraceae), to 22 scent compounds produced by other moth-pollinated flowers and to eight ubiquitous "green leaf volatiles." Females' EAGs were generally 1.5- to 2-fold greater than those observed for male moths. Female:male EAG rank orders were significantly correlated, but marked differences in order were observed for some compounds (e.g., benzyl alcohol, cinnamic aldehyde, geraniol, and linalool). Linalool, benzyl acetate, methyl salicylate, and pyranoid linalool oxide elicited the largest EAG responses (-1.2 to -0.8 mV) among scent compounds fromC. breweri. EAG responses were significantly lower for monoterpenes as a pooled compound class than for aromatic esters, alcohols and aldehydes, fatty acid derivatives, N-bearing compounds and oxygenated terpenoids. EAG responses to structurally related scent compounds were not significantly different in most cases. Both male and femaleH. lineata were sensitive to mostC. breweri scent compounds at 10(-2) to 10(-4) µg/µl doses, and rank order in potency varied with the dose/concentration tested.H. lineata's olfactory sensitivity to diverse volatile compounds across a range of doses/concentrations suggests that a broad array of volatiles could function as floral attractants for foraging hawkmoths.
Article
ABSTRACT Comprising a land area of ca. 90,000 km,, less than one twentieth (5%) the land area of the southern African subcontinent, the Cape Floristic Region (CFR) is, for its size, one of the world’s richest areas of plant species diversity. A new synoptic flora for the Region has made possible an accurate reassessment of the flora, which has an estimated 9030 vascular plant species (68.7% endemic), of which 8920 species are flowering plants (69.5% endemic). The number of species packed,into so small an area is remarkable,for the temperate,zone and compares,favorably with species richness for areas of similar size in the wet tropics. The Cape region consists of a mosaic,of sandstone,and shale substrata with local areas of limestone. It has a highly dissected, rugged topography, and a diversity of climates with rainfall mostly falling in the winter months and varying from 2000 mm,locally to less than 100 mm. Ecological gradients are steep as a result of abrupt differences in soil, altitude, aspect, and precipitation. These factors combine to form an unusually large number of local habitats for plants. Sandstone-derived soils have characteristically low nutrient status, and many plants present on such soils have low seed dispersal capabilities, a factor promoting localized distributions. An unusual family composition includes Iridaceae, Aizoaceae, Ericaceae, Scrophulariaceae, Proteaceae, Restionaceae, Rutaceae, and Orchidaceae among the 10 largest families in the flora, following Asteraceae and Fabaceae, as the most speciose families. Disproportionate radiation has resulted in over 59.2% species falling in the 10 largest families and 77.4% in the largest 20 families. Twelve genera have more than 100 species and the 20 largest genera contribute some 31% of the total species. Species richness of the Cape flora is hypothesized to be the result of geographic and parapatric radiation in an area with a mosaic of different habitats due to local soil, climate, and altitudinal differences that combine,to produce steep ecological gradients. Also contributing to the diversity has been a relatively stable geological history since the end of the Miocene that saw the establishment,of a semi-arid and extreme seasonal climate at the southwestern,part of southern Africa. Key words: floristics, Mediterranean-type climate, phytogeography, plant diversity, southern Africa, speciation. Situated at the southwestern tip of the African
Article
Disa remota, a new species of Orchidaceae belonging to Disa Sect. Disella, is described from the South Western Cape, South Africa
Article
Morphological, geographical and ecological evidence suggests thatEncelia virginensis is a true-breeding diploid species derived from hybrids ofE. actoni andE. frutescens. To test this hypothesis, we examined the chloroplast and nuclear DNA of severalEncelia species. PCR amplification targeted three separate regions of chloroplast DNA:trnK-2621/trnK-11,rbcL/ORF106, andpsbA3/TrnI-51, which amplify 2600bp, 3300bp and 3200bp fragments respectively. Restriction fragment analysis of chloroplast DNA revealed no variation that could be used to discriminate between the parent species. A RAPD analysis using 109 dekamer primers was used to analyze the nuclear genome.Encelia actoni andE. frutescens were distinguished by several high-frequency RAPD markers. In populations ofE. virginensis, these markers were detected in varying proportions, and no unique markers were found. Evidence from the nuclear genome supports the hypothesis thatE. virginensis is of hybrid origin. ThatE. virginensis may have arisen by normal divergent speciation followed by later introgression remains a possibility, however, and is not formally ruled out here. Diploid hybrid speciation inEncelia differs from other documented cases in that there are no discernible chromosome differences between the species, and all interspecific hybrids are fully fertile. In addition, apparent ecological selection against backcross progeny provides an external barrier to reproduction between F1 progeny and the parental species. These characteristics suggest that hybrid speciation inEncelia may represent an alternative model for homoploid hybrid speciation involving external reproductive barriers. In particular, this may be the case for other proposed diploid hybrid taxa that also exhibit little chromosomal differentiation and have fertile F1s.
Article
Field observations showed that three South African orchid species,Satyrium carneum, S. coriifolium andS. princeps, are pollinated by sunbirds. Foraging sunbirds insert their bills into the labellum chamber of the flowers and suck nectar from the labellum spurs with their tongues. The column overarches the entrance to the labellum and pollinaria become affixed to the upper mandible of the bill. Birds often attempt to remove pollinaria by rubbing their bills against a branch, but are mostly unsuccessful due to the large plate-like viscidia which attach the pollinaria very firmly to the bill. Other modifications for bird pollination in theseSatyrium species may include the red, carmine or orange colour of the flowers, sturdy inflorescence stems used for perching and large amounts of dilute nectar in the spurs. EachSatyrium species was pollinated by several species of sunbird, and despite some differences in flowering time, occasional hybrids occur at a site whereS. carneum andS. coriifolium share the same sunbird pollinators.
Article
Intraspecific variation in floral traits may reflect adaptive shifts in the pollination system of a plant. This idea was tested by examining the pollination biology of Satyrium hallackii H. Bolus., an orchid which has spurs varying from 8 to 36 mm among populations in southern Africa. Field observations showed that the short-spurred form (S. hallackii subsp. hallackii) in coastal fynbos habitats is pollinated by bees, while the long-spurred form (S. hallackii subsp. ocellatum) in grassland habitats is pollinated primarily by hawkmoths and, secondarily, by long-tongued flies. The shift between hawkmoths and bees as pollinators may have been promoted by an ecological gradient in South Africa: carpenter bees are common in coastal fynbos habitats, but rare in grassland habitats where there are few available nesting sites. On the other hand, hawkmoths are common in grassland habitats, but rare in fynbos where there are few palatable host-plants. The formation of pollination ecotypes across pollinator gradients has probably been a major factor in the diversification of South African plants with specialized pollination systems.
Article
Peer Reviewed http://deepblue.lib.umich.edu/bitstream/2027.42/31361/1/0000273.pdf
Article
Two spectacular new orchid species from the semi-arid Karoo region of South Africa are described here. Both have been confused with Satyrium erectum Sw. in the past, yet have clear diagnostic characters which justify their recognition as distinct species. Satyrium pulchrumS. Johnson & Kurzweil sp. nov., known only from an isolated granite inselberg in Namaqualand, appears to be the sister taxon to S. erectum, whereas Satyrium pallensS. Johnson & Kurzweil sp. nov., known from several populations along the southern margins of the Karoo, has closer affinities to Saprium longicolleLindl. These four species form a distinct monophyletic group characterized by several synapomorphies. The allopatric distribution pattern and considerable divergence in floral characters of the sister species suggest that speciation involved shifts in the pollination system of geographically isolated populations.
Article
Aim To evaluate the role of habitat heterogeneity on species richness and turnover in the mega species‐rich Cape Floristic Region (Cape), the mediterranean region of southern Africa. Location The Cape and Drakensberg regions of southern Africa. Methods Bioclimatic data were used to estimate habitat amount and habitat heterogeneity in the Cape and Drakensberg regions; these data were then used to explain the patterns of species diversity in the Pentaschistis clade (Poaceae) in these two regions. Habitat variables were used to create ‘bioclimatic units’ to characterize 1′× 1′ cells in southern Africa and to describe the niches of species. Using these bioclimatic units, the niche and range sizes of species in the two regions were compared. A phylogram was used to test for age and lineage effects. Results Pentaschistis species diversity and turnover are higher in the Cape than the Drakensberg. There is no significant difference in the habitat amount and heterogeneity between the two regions. Species occupy the same range of estimated niche sizes, yet there are significantly more range‐restricted Pentaschistis species in the Cape. Main conclusions The roles of age‐ and lineage‐related effects are rejected; biodiversity differences lie in the regions. Current macrohabitat does not explain the differences in biodiversity between the two regions. The larger number of range‐restricted species in the Cape cannot be explained by dispersal mechanism or the occupation of range‐restricted habitats. Species of Pentaschistis and other Cape clades share characteristics associated with species from historically climatically stable areas, and palaeoclimatic and palaeontological evidence indicates the Cape climate has been more stable than the Drakensberg climate throughout the Pleistocene. We conclude that the corresponding lack of extinction might have allowed an accumulation of species in the Cape. Similar climatic and biological evidence for the south‐west Australian Floristic and Mediterranean regions indicate that the same mechanism might explain the high species richness of these mediterranean regions.
Article
Taxon cycles are sequential phases of expansion and contraction of the ranges of species, associated generally with shifts in ecological distribution. The important contribution of the taxon cycle to biogeographical analysis is its emphasis on evolutionary and ecological interactions among colonizing and resident species, which influence their extinction dynamics and establish patterns of geographical distribution. Taxon cycles were inferred originally from the distribution of species across island archipelagos, where a correlation was noted between gaps in island occupancy and the degree of phenotypic differentiation. This pattern implied that phases of colonization were followed by range contraction, while endemic Antillean species that were undifferentiated between islands suggested secondary expansion and the beginning of a new cycle. This interpretation was met with scepticism, but reconstruction of phylogenetic relationships from gene sequences has now permitted us to characterize taxon cycles in Lesser Antillean birds. The relative timing of phases of the cycle can be deduced from genetic divergence between island populations. We have found that taxon cycles have periods in the order of 106 years and that cycles in different lineages occur independently of each other and independently of Pleistocene climate cycles. Individual island populations may persist for several millions of years on the larger islands of the Lesser Antilles; occasional expansion phases lead to the replacement of island populations that have disappeared, thus reducing the archipelago-wide rate of extinction to nil. What drives taxon cycles is unknown, but we speculate that they may be caused by co-evolution with enemy populations, and a probable mechanism would involve infrequent mutations influencing parasite virulence and avian host disease resistance. Taxon cycles undoubtedly occur on continents, but the geographical configuration of island archipelagos reveals more clearly their presence and invites their study.
Article
Clarkia breweri (Onagraceae) is the only species known in its genus to produce strong floral fragrance and to be pollinated by moths. We used gas chromatography-mass spectrometry (GC-MS) to identify 12 abundant compounds in the floral headspace from two inbred lines ofC. breweri. These volatiles are derived from two biochemical pathways, one producing acyclic monoterpenes and their oxides, the other leading from phenylalanine to benzoate and its derivatives. Linalool and linalool oxide (pyran form) were the most abundant monoterpenoids, while linalool oxide (furan form) was present at lower concentrations. Of the aromatic compounds detected, benzyl acetate was most abundant, whereas benzyl benzoate, eugenol, methyl salicylate, and vanillin were present as minor constituents in all floral samples. The two inbredC. breweri lines differed for the presence of the additional benzenoid compounds isoeugenol, methyleugenol, methylisoeugenol, and veratraldehyde. We also analyzed floral headspace fromC. concinna, the likely progenitor ofC. breweri, whose flowers are odorless to the human nose. Ten volatiles (mostly terpenoids) were detected at low concentrations, but only when headspace was collected from 20 or more flowers at a time. Trans--ocimene was the most abundant floral compound identified from this species. Our data are consistent with the hypothesized recent evolution of floral scent production and moth pollination inC. breweri.
Article
The morphologically diverse flowers in the genusSatyrium reflect adaptations to a wide range of pollinators. Several recently discovered pollination systems inSatyrium are described and illustrated here; these include pollination by solitary bees, carrion flies, butterflies and moths. Two basic types of floral mechanism are recognised inSatyrium: (1) Species pollinated by lepidoptera and birds have long floral spurs and plate-like viscidia seated in lateral rostellum notches; these viscidia become attached to the proboscis or bill of the pollinator. (2) Species pollinated by flies and bees have relatively short floral spurs and globose viscidia seated in terminal rostellum notches; these viscidia become attached to the face, thorax or eyes of the pollinator.
Article
Plant species have accumulated in the Cape region of southern Africa to a much greater degree than in areas of equivalent size in the rest of the subcontinent. Although this could be a consequence simply of lower extinction rates in the Cape, most researchers have invoked high rates of ecological speciation, driven by unique aspects of the Cape environment, as the primary explanation for this richness. To assess these ideas, we analyzed the frequencies of ecological shifts among 188 sister species pairs obtained from molecular phylogenies of eight Cape clades. Ecological shifts were evident in 80% of sister species pairs, with general habitat, pollinator, and fire-survival strategy shifts being especially frequent. Contrary to an established idea that shifts in soil type are frequently associated with speciation of Cape taxa, these shifts were relatively rare, occurring in just 17% of species pairs. More cases of sister species divergence are accompanied solely by floral than by vegetative diversification, suggesting an important role for pollinator-driven speciation. In an analysis of two large orchid genera that have radiated in both the Cape and the rest of southern Africa, the frequency of ecological shifts (general habitat, soil type, altitude and flowering time), did not differ between sister species pairs in the Cape region and those outside it. Despite suggestions that Cape plants tend to have small range sizes and show fine-scale patterns of speciation, range size did not differ significantly between species in the Cape and those outside it. We conclude that ecological speciation is likely to have been important for radiation of the Cape flora, but there is no evidence as yet for special “Cape” patterns of ecological speciation.
Article
Satyrium situsanguinum is described as a new species from the Slanghoek Mountains of the southwestern part of the Cape Floristic Region, South Africa. It is recognised by the urceolate-campanulate cauline, leaf sheaths, and white flowers with spurs longer than the ovary.
Article
We studied the patterns of adaptive radiation in Disa, a large orchid genus in southern Africa. A cladogram for 27 species was constructed using 44 morphological characters. Pollination systems were then mapped onto the phylogeny in order to analyze pathways of floral evolution. Shifts from one pollination system to another have been a major feature of the evolutionary diversification of Disa. Unlike many plant genera that are pollinated mainly by a single group of insects, radiation in Disa has encompassed nearly all major groups of pollinating insects; in all, 19 different specialized pollination systems have been found in the 27 species included in this analysis. Another striking pattern is the repeated evolution of broadly similar pollination systems in unrelated clades. For example, butterfly-pollinated flowers have evolved twice; showy deceptive flowers pollinated by carpenter bees, twice; long-spurred flowers pollinated by long-tongued flies, four times; night-scented flowers pollinated by moths, three times; and self-pollination, three times. This suggests that a few dominant pollinator species in a region may be sufficient to generate diversification in plants through repeated floral shifts that never retrace the same pathways.
Article
Variation in floral shape is of major interest to evolutionary and pollination biologists, plant systematists and developmental geneticists. Quantifying this variation has been difficult due to the three-dimensional (3D) complexity of angiosperm flowers. By combining 3D geometric representations of flowers obtained by micro-computed tomography scanning with geometric morphometric methods, well established in zoology and anthropology, floral shape variation can be analyzed quantitatively, allowing for powerful interpretation and visualization of the resulting patterns of variation.
Article
A species tree was reconstructed for the mainly African terrestrial orchid genus Satyrium. Separate phylogenetic analysis of both plastid and ribosomal nuclear DNA sequences for 63 species, revealed extensive topological conflict. Here we describe a detailed protocol to deal with incongruence involving three steps: identifying incongruence and testing its significance, assessing the cause of incongruence, and reconstructing the species tree. The Incongruence Length Difference test revealed that many cases of incongruence were non-significant. For the remaining significant cases, results from taxon jack-knifing experiments and parametric bootstrap suggested that non-biological artefacts such as sparse taxon sampling and long-branch attraction could be excluded as causes for the observed incongruence. In order to evaluate biological causes, such as orthology/paralogy conflation, lineage sorting, and hybridization, the number of events was counted that needs to be invoked a-posteriori to explain the observed pattern. In most cases where incongruence was significant, this resulted in a similar number of events for each of these different causes. Only for the three species from south east Asia, that form a monophyletic clade, hybridization was favoured over the alternative causes. This conclusion is based on the large number of events that needs to be invoked, in order for either orthology/paralogy conflation or lineage sorting to have been the cause of the incongruence+morphological evidence. The final species tree presented here is the product of the combined analysis of plastid and ITS sequences for all non-incongruent species and a-posteriori grafting of the incongruent clades or accessions onto the tree.
Article
Like island-endemic taxa, whose origins are expected to postdate the appearance of the islands on which they occur, biome-endemic taxa should be younger than the biomes to which they are endemic. Accordingly, the ages of biome-endemic lineages may offer insights into biome history. In this study, we used the ages of multiple lineages to explore the origin and diversification of two southern African biomes whose remarkable floristic richness and endemism has identified them as global biodiversity hotspots (succulent karoo and fynbos). We used parsimony optimization to identify succulent karoo- and fynbos-endemic lineages across 17 groups of plants, for which dated phylogenies had been inferred using a relaxed Bayesian (BEAST) approach. All succulent karoo-endemic lineages were less than 17.5 My old, the majority being younger than 10 My. This is largely consistent with suggestions that this biome is the product of recent radiation, probably triggered by climatic deterioration since the late Miocene. In contrast, fynbos-endemic lineages showed a broader age distribution, with some lineages originating in the Oligocene, but most being more recent. Also, in groups having both succulent karoo- and fynbos-endemic lineages, there was a tendency for the latter to be older. These patterns reflect the greater antiquity of fynbos, but also indicate considerable recent speciation, probably through a combination of climatically-induced refugium fragmentation and adaptive radiation.
Viscidia globular-shaped, lateral sepals larger than the median sepal and lateral petals, but all projecting in the same plane…………………………………………….………S. situsanguinum Supplementary data to this article can be
Viscidia globular-shaped, lateral sepals larger than the median sepal and lateral petals, but all projecting in the same plane…………………………………………….………S. situsanguinum Supplementary data to this article can be found online at http://dx. doi.org/10.1016/j.sajb.2017
The Kew Plant Glossary
  • H Beentje
Beentje, H., 2010. The Kew Plant Glossary. Kew Publishing, Royal Botanic Gardens, Kew. Bolus, H., 1893-1896. Icones Orchidearum Autro-Africanarum Extratropicarum. Vol. 1. Wesley and Son, London.
Restore our sense of species
  • K D B Dijkstra
Dijkstra, K.D.B., 2016. Restore our sense of species. Nature 533, 172-174.
Fynbos: Ecology, Evolution, and Conservation of a Megadiverse Region
  • T Kraaij
  • B W Van Wilgen
Kraaij, T., Van Wilgen, B.W., 2014. Drivers, ecology, and management of fire in fynbos. In: Allsopp, N., Colville, J.F., Verboom, A.G. (Eds.), Fynbos: Ecology, Evolution, and Conservation of a Megadiverse Region. Oxford University Press, Oxford, pp. 47-72.