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A monograph of the genus Polhillia (Genisteae: Fabaceae)
Abstract
Polhillia is a small, but poorly known genus of legumes endemic to the Greater Cape Floristic Region (GCFR) of South Africa. The genus was described three decades ago to accommodate species erroneously placed in Argyrolobium and other Cape legume genera. Polhillia is the third most threatened plant genus in South Africa, hence priority for taxonomic study and current knowledge on distribution patterns are essential for conservation interventions. Eight species were known at the start of this study, all of which are threatened with extinction. Species boundaries were, however, unclear and many Renosterveld fragments, in particular in the Overberg, required further exploration in pursuit of the various Polhillia species. The phylogenetic relationships among species and monophyly of the genus, especially regarding the position of the morphological aberrant P. involucrata, had not been tested. This study was built upon a foundation of widespread field sampling and analysis of herbarium specimens. Having considered morphological, anatomical, palynological and molecular data, we present an updated taxonomy of the genus Polhillia. Morphological characters between species were often obscure and unique characters were uncommon, as such species are recognized based on unique combinations of characters. Pollen and leaf anatomical studies did not provide substantial taxonomically informative characters, although some interspecific differences were noted. Molecular phylogenetic reconstructions confirm Polhillia to be monophyletic and sister to Argyrolobium, and that Argyrolobium may not be monophyletic. The morphologically distinct species, P. involucrata, is strongly supported as sister to the rest of the genus. Internal phylogenetic resolution in Polhillia is weak in many clades, due to the low variability among DNA markers studied, and several polytomies are still present. Based on the morphological and molecular evidence, we place P. involucrata in the new monotypic subgenus Roseopolhillia. Four new species are described (P. fortunata B.du Preez, P. groenewaldii B.du Preez, P. stirtoniana B.du Preez, P. xairuensis B.du Preez), and a previously recognized species (P. canescens C.H.Stirt.) is placed in synonymy under P. connata (Harv.) C.H.Stirt. Red data list assessments are provided for all species to highlight their conservation importance. Maps and compound colour plates are provided for each species.
... Таким же образом в разных отраслях науки термин «монография» может иметь разное значение. Например, в естественнонаучной среде до сих пор сохраняется изначальное определение монографии как описания одного биологического вида, рода вне зависимости от объема материала (Du Preez B., 2021). ...
... Он обозначал скорее жанр научного произведения без привязки к материальной конструкции носителя (самостоятельное издание / часть научного журнала). До сих пор в естествознании это определение может быть применено к описанию какого-либо рода, вида (Du Preez, 2021). Впоследствии термин из естествознания перешел в другие отрасли и стал применяться в качестве синонима понятия «научный труд (трактат) по одному аспекту предмета» (Allen, 1981). ...
Today the term “monograph” requires careful consideration, since the essence of the term itself is being changed over time and it takes into account the changing conditions in scholarly communication. The purpose of article is by means of the terminological analysis to identify the essential attributes of monograph, reflected in its various definitions. The article considers the terminological analysis of the term “monograph” according to a number of attributes: its material structure, intended purpose, presentation of material, coverage, number of authors, target audience, functions of a monograph for an author and a reader. The author used Russian language and English language dictionaries and research results as the main sources. There considered several approaches to understanding the term “monograph” (natural science interpretation of a monograph as a description of individual types and subjects, a monograph as a treatise on a single theme or problem, and a monograph as a separate publication in the form of a book). Main results are: the determination of the the attributes of a monograph reflecting its essence from the point of view of Russian speaking and English speaking practice, as well as the attributes of a scholarly monograph. The distinction among scholarly, industrial-practical and popular science monographs is typical only for Russian speaking practice, while monograph is primarily a treatise (scientific edition) for English sources. A reputational function of a monograph can become the prevailing function for an author, and sometimes it can be the only one purpose to write it. It is concluded that the main attributes of a scholarly monograph can be considered: the intended purpose - a scholarly one; the coverage - one theme or a problem; the number of authors - one or more authors; the target audience - specialists; the function for an author - the reputational one; the function for a reader - the informative one.
... For example, over 20 new legume species have been recently described from various genera, including Aspalathus L., Otholobium C.H.Stirt., Polhillia C.H.Stirt., Psoralea L. and Rhynchosia Lour. (Curtis et al. 2013;Moteetee et al. 2014;Muasya 2016, 2017;Bello et al. 2017;Du Preez et al. 2021). Members of Indigofera Section Brachypodae, particularly the I. brachystachya group (I. ...
In this study, Indigofera wenholdiae , a new species of Fabaceae from the Agulhas Plain Region of the Western Cape Province, South Africa, is described. A composite photographic plate is included along with a distribution map, description of habitat and ecology and proposed IUCN conservation status. Indigofera wenholdiae is unique in the I. brachystachya group by having digitately compound (vs. pinnately compound) leaves, white and unscented flowers (vs. pink and sweetly scented flowers) and grows on sandstone hillsides (vs. coastal limestone plains and outcrops).
The butterfly shaped keel flowers are among the most successful pollination syndromes in angiosperms. These flowers steer the mechanical interaction with bees and thus are hypothesized to accelerate pollinator driven diversification. The highly labile evolution of keel flowers in Papilionoideae (Fabaceae) provides a suitable system to test this hypothesis but a robust phylogeny is lacking.
Using 1,456 low copy nuclear loci, we confidently resolve the early divergence history of Papilionoideae. Constrained by this backbone phylogeny, we generated a time tree for 3,326 Fabales to evaluate the tempo and mode of diversification within a state dependent evolutionary framework.
The first keel flowers emerged around 59.0 Ma in Papilionoideae, predating the earliest fossil by 3-4 million years. The Miocene diversification of Papilionoideae coincided with rapid evolution of keel flowers. At least seven independent origins and twenty-seven losses of keel flowers were identified in Papilionoideae, Polygalaceae, and Cercidoideae during this time. However, the state-dependent diversification model was not favored.
Lack of radiation associated with keel flowers suggests that diversification within Papilionoideae was not solely driven by pollinator-mediated selection, but instead an outcome of the synergistic effects of multiple innovations including nitrogen fixing and chemical defense as well as dispersal to the subtropical and temperate regions.
Premise of the study:
A diverse range of pollen morphologies occurs within the large, paraphyletic legume subfamily Caesalpinioideae, especially among early-branching lineages. Previous studies have hypothesized an association between surface ornamentation and pollination syndrome or other aspects of pollen function such as desiccation tolerance and adaptations to accommodate volume changes.
Methods:
We reviewed caesalpinioid pollen morphology using light microscopy, scanning and transmission electron microscopy, in combination with a literature survey of pollination vectors.
Key results:
Pollen structural diversity is greatest in the early-branching tribes Cercideae and Detarieae, whereas Cassieae and Caesalpinieae are relatively low in pollen diversity. Functional structures to counter desiccation include opercula (lids) covering apertures and reduced aperture size. Structures preventing wall rupture during dehydration and rehydration include different forms of colpi (syncolpi, parasyncolpi, pseudocolpi), striate supratectal ornamentation, and columellate or granular wall structures that resist tensile or compressive forces respectively. Specialized aperture structures (Zwischenkörper) may be advantageous for efficient germination of the pollen tube.
Conclusions:
In Detarieae and Cercideae in particular, there is potential to utilize pollen characters to estimate pollination systems where these are unknown. Supratectal verrucae and gemmae have apparently evolved iteratively in Cercideae and Detarieae. At the species level, there is a potential correlation between striate/verrucate patterns and vertebrate pollination.
Asia, especially the temperate Sino-Himalayan region is one of the four major diversity centers of Indigofera. Pollen morphology of Indigofera species in the Sino-Himalayan region is poorly known. In this study, pollen morphology of 52 samples representing 43 Chinese Indigofera species and two varieties was examined using scanning electron microscopy to evaluate its taxonomic significance. Parasyncolpate pollen grains were described in Indigofera for the first time. Cluster and principal component analyses were conducted based on four quantitative and three qualitative pollen characters. Five groups were recognized within Chinese Indigofera in the cluster analysis, but only one can be separated by the first three principal components. The shape and size of pollen grains in Indigofera are highly variable. Consequently, both the characters lack any significant taxonomic value. The number of apertures, tectum architecture and perforation density shows some taxonomic significance. The pollen morphology exhibits obvious phylogenetic and biogeographical significance on large scales in Indigofera. Although pollen characters alone are insufficient to reconstruct the taxonomic relationships within Indigofera, palynological data can provide some useful information for the species-level revisions.
Gene trees from independent molecular markers often differ. Simple data matrix concatenation cannot represent the
various biologically meaningful processes that underlie these differences, and in an age of high-throughput DNA sequencing and coalescent-based species tree inference methods, the approach seems increasingly quaint. I argue that concatenation still has its place in our suite of approaches, but that care should be taken when deciding which data might be combined under what circumstances. I present recommendations for avoiding the worst pitfalls of the approach.
Oberholzeria etendekaensis, a succulent biennial or short-lived perennial shrublet is described as a new species, and a new monotypic genus. Discovered in 2012, it is a rare species known only from a single locality in the Kaokoveld Centre of Plant Endemism, north-western Namibia. Phylogenetic analyses of molecular sequence data from the plastid matK gene resolves Oberholzeria as the sister group to the Genisteae clade while data from the nuclear rDNA ITS region showed that it is sister to a clade comprising both the Crotalarieae and Genisteae clades. Morphological characters diagnostic of the new genus include: 1) succulent stems with woody remains; 2) pinnately trifoliolate, fleshy leaves; 3) monadelphous stamens in a sheath that is fused above; 4) dimorphic anthers with five long, basifixed anthers alternating with five short, dorsifixed anthers, and 5) pendent, membranous, one-seeded, laterally flattened, slightly inflated but indehiscent fruits.
We carried out a comparative morphological study to evaluate the taxonomic value of seed and seedling traits of Entada polystachya and E. simplicata (Leguminosae, Mimosoideae, Mimoseae). Seeds of both species were collected from wild populations in Roraima State, Brazil. Our results show consistent quantitative and qualitative differences between these species regarding their seeds and seedlings. Testa fracture lines, funiculus impression, lens characters, radicle shape and length, and cotyledon lobes length, seedling morphology group, number of pinnae at first node, and hypocotyl length permit a straightforward distinction of E. polystachya from E. simplicata, supporting a recent treatment of the latter taxon as a distinct species, endemic to Roraima State, northern Amazonia, Brazil.
A comparative study of bark anatomy of all three taxa of the genus Virgilia has revealed interesting differences relating to the taxonomic relationships of the species and subspecies and also to the marked ecological differences (as reflected in the bark anatomy) between Virgilia oroboides subsp. oroboides (exposed to high fire frequencies in the western parts of the Cape Province of South Africa, from Cape Town to Swellendam) and V. oroboides subsp. ferruginea and Virgilia divaricata (growing in areas of relatively low fire frequency along the southern Cape coast from George to Port Elizabeth). The conspicuous difference in the appearance of the bark (thick and corky in V. oroboides subsp. oroboides; thin and smooth in V. oroboides subsp. ferruginea and V. divaricata) results from a distinct difference in the sclerification of periderm cells. Detailed descriptions of the bark anatomy of all three taxa are presented, showing a pattern of variation that supports the delimitation of species and subspecies. The discovery of crystals in the trichome cells of V. oroboides subsp. ferruginea appears to be a first record of the presence of crystals inside trichomes in the Fabaceae and is a useful diagnostic character for the subspecies. A remarkable feature of the bark of Virgilia is the common occurrence of acicular crystals arranged in radial (sheath-like) aggregates.
Resolving the phylogenetic relationships of the deep nodes of papilionoid legumes (Papilionoideae) is essential to understanding the evolutionary history and diversification of this economically and ecologically important legume subfamily. The early-branching papilionoids include mostly Neotropical trees traditionally circumscribed in the tribes Sophoreae and Swartzieae. They are more highly diverse in floral morphology than other groups of Papilionoideae. For many years, phylogenetic analyses of the Papilionoideae could not clearly resolve the relationships of the early-branching lineages due to limited sampling. In the eight years since the publication of Legumes of the World, we have seen an extraordinary wealth of new molecular data for the study of Papilionoideae phylogeny, enabling increasingly greater resolution and many surprises. This study draws on recent molecular phylogenetic studies and a new comprehensive Bayesian phylogenetic analysis of 668 plastid matK sequences. The present matK phylogeny resolves the deep-branching relationships of the papilionoids with increased support for many clades, and suggests that taxonomic realignments of some genera and of numerous tribes are necessary. The potentially earliest-branching papilionoids fall within an ADA clade, which includes the recircumscribed monophyletic tribes Angylocalyceae, Dipterygeae, and Amburanae. The genera Aldina and Amphimas represent two of the nine main but as yet unresolved lineages comprising the large 50-kb inversion clade. The quinolizidine-alkaloid-accumulating Genistoid s.l. clade is expanded to include Dermatophyllum and a strongly supported and newly circumscribed tribe Ormosieae. Sophoreae and Swartzieae are dramatically reorganized so as to comprise monophyletic groups within the Core Genistoid clade and outside the 50-kb inversion clade, respectively. Acosmium is excluded from the Genistoids s.l. and strongly resolved within the newly circumscribed tribe Dalbergieae. By providing a better resolved phylogeny of the earliest-branching papilionoids, this study, in combination with other recent evidence, will lead to a more stable phylogenetic classification of the Papilionoideae.
The phytochemistry of the Leguminosae, a large plant family with more than 750 genera (in 40 tribes) and 18,000 species, is comparably well documented. Several types of alkaloids, non-protein amino acids, amines, flavonoids, isoflavonoids, coumarins, phenylpropanoids, anthraquinones, di-, sesqui- and triterpenes, cyanogenic glycosides, protease inhibitors and lectins have been described in this family, most of which function as defence chemicals and/or as signal compounds.Nucleotide sequences of rbcL of over 450 legumes have been determined in our laboratory that provide a phylogenetic framework to map the distribution of the main secondary metabolites. We have selected more than 150 genera which cover most tribes of the Leguminosae. In several instances, a particular group of secondary metabolites is confined to a systematically related group of species or genera. For example, the distribution of quinolizidine alkaloids is restricted to the genistoids s.l. whereas many of the other legumes produce non-protein amino acids. The distribution of quinolizidine alkaloids and non-protein amino acids is thus almost mutually exclusive. In some instances all members of a monophyletic clade share a chemical defence character (this would favour its use as a taxonomic marker), in other instances not. In many cases a loss of a particular defence trait in a member within a monophyletic taxon is substituted by a different one, which can be chemical (e.g. pyrrolizidine alkaloids instead of quinolizidine alkaloids in Crotalaria) or even mechanical (e.g., several brooms have only traces of alkaloids but produce spikes and thorns instead) by nature. Since a good taxonomic marker should be consistent for all members of a monophyletic clade, the main question is rather, what were the selective forces to activate the corresponding genes in one taxon and to turn them off in another. Since secondary metabolites play a vital role as defence or signal compounds, their occurrence apparently reflects adaptations and particular life strategies imbedded in a phylogenetic framework. A comparison of the distribution of secondary metabolites in plants with their phylogenetic relationships, thus offers information on the underlying evolutionary and ecological processes. It also offers insight into life strategies and taxonomic relationships.
Quartz fields are islands of distinct vegetation in southern Africa. Such habitats differ from surrounding shale
substrate in geomorphological and climatic attributes, and are dominated by a predominantly succulent flora
with between 14% and 91% endemism. Previous studies have identified and surveyed quartz fields within
the Succulent Karoo biome, but little is known about the Overberg quartz–silcrete fields located in the
Renosterveld vegetation (Fynbos biome). This study maps the occurrence of quartz–silcrete fields in the
Overberg (Eastern and Central Rûens Shale Renosterveld) and investigates if such fields support distinct vegetation compared with surrounding shales. Forty-seven plant species were recorded, 19 of which are endemic to the quartz–silcrete patches, including several newly discovered species in vascular plant families Cyperaceae (Ficinia), Iridaceae (Hesperantha) and Fabaceae (Aspalathus, Otholobium, Polhillia, Xiphotheca). Five species among these are described in this paper: Aspalathus quartzicola C.H.Stirt. & Muasya, Aspalathus microlithica C.H.Stirt. & Muasya, Ficinia overbergensis Muasya & C.H.Stirt., Otholobium curtisiae C.H.Stirt. & Muasya, and Polhillia curtisiae C.H.Stirt. & Muasya. Detailed floristic composition of 25 quartz fields is surveyed, together with their conservation status. The Overberg Quartzveld is a critically endangered vegetation type that is the sole locality for 18 Red Listed plant species; which include seven new taxa. It is a distinct vegetation unit embedded within Rûens Shale Renosterveld in the eastern Overberg region of South Africa. These quartz patches have been overlooked in the past and we emphasize the need for further research and conservation attention of these habitats.
A revision of the generic and infrageneric taxonomy of Podalyria (Fabaceae, Podalyrieae) is presented. The genus comprises 17 species, of which 16 are endemic to the Cape Floristic Region of South Africa and one extends eastwards to southern KwaZulu-Natal. Morphological, cytological and chemical characters are briefly discussed. A cladistic analysis of 19 morphological characters and one chemical character resulted in a partially resolved topology with two main clades. These two groups are described as sections, namely Villosae and Podalyria. Two new species are described: P. leipoldtii and P. variabilis, and one new combination P. rotundifolia is made. Historically, the application of names in Podalyria has been variable and unreliable, so that considerable effort was required to unravel the intricate nomenclature, synonymy, and typification of the species. This revision (the first since 1862) also includes full descriptions, diagnostic characters, photographs, illustrations, and distribution maps. The red data list status of five of the threatened species is given.
Variation in the fire-survival strategy of the fynbos, legume tribesPodalyrieae andLiparieae was studied, since it is often the only conspicuous difference between morphologically similar taxa. Two main strategies are apparent: sprouters, taxa which are able to sprout from a woody rootstock after fire and non-sprouters, those which only recruit from seed after fire. In fynbos legumes sprouting and non-sprouting taxa differ in their habitat specificity, population densities, relative regional abundance, and in seed germination tempo. Speciation patterns, as inferred from an analysis of the geographical distribution and habitat specificity of the species, are discussed. Problems relating to the use of sprouting versus non-sprouting as a taxonomic character in fynbos legumes are addressed and possible solutions are given.
Six new species of Thesium endemic to the Greater Cape Floristic Region (GCFR) of South Africa are described and illustrated. These are Thesium aspermontanum, T. dmmagiae, T. neoprostratum, T. nigroperianthum, T. rhizomatum, and T. stirtonii. In addition, Thesium assimile var. pallidum is elevated to species rank as T. sawae. Morphological and ecological
differences of each species, along with their putative affinities, preliminary conservation status, phenology, etymology, and distributional maps are presented
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.
The first of a two-part taxonomic revision of the morphologically complex Schoenus cuspidatus and allies group is presented. This revision builds on two recent taxonomic works of which the first transferred 24 southern African species from Tetraria and Epischoenus into Schoenus, and the second revised the taxonomy of the Schoenus compar – Schoenus pictus and allies group, as well as described three new species from South Africa. Here, we use data from recent field collections and a review of specimens from 12 herbaria to revise the delimitations and distributions of three species (Schoenus bolusii, Schoenus exilis and Schoenus graminifolius). In addition,we describe seven new species: six of which are endemic to the Cape Floristic Region (Schoenus calceolus, Schoenus crassiculmis, Schoenus submarginalis, Schoenus prophyllus, Schoenus purpurascens and Schoenus quartziticus), while the seventh is endemic to the Eastern Cape and KwaZulu Natal Provinces of South Africa (Schoenus limosus).We also resolve nomenclatural and species delimitation issues in Schoenus auritus and Schoenus ligulatus, with Schoenus autumnalis and Schoenus variabilis being subsumed in an enlarged circumscription of Schoenus ligulatus. Species in the Schoenus cuspidatus group are caespitose, perennial graminoids, with scapose and terete culms. However, there are differences in sheath and ligule type, which can be either firm or membranaceous, as well as leaf type, which vary from channelled and terete to non-channelled and flat. Importantly, differences in spikelet and nutlet shape distinguish many of the species in this group. A taxonomic key is presented, the nomenclature is updated, and detailed descriptions and distribution maps are provided for these 12 Schoenus species.
Ten new species of Otholobium from South Africa are described: O. accrescens C. H. Stirt. & Muasya, O. dreweae C. H. Stirt. & Muasya, O. lanceolatum C. H. Stirt. & Muasya, O. lucens C. H. Stirt. & Muasya, O. nitens C. H. Stirt. & Muasya, O. piliferum C. H. Stirt. & Muasya, O. prodiens C. H. Stirt. & Muasya, O. sabulosum C. H. Stirt. & Muasya, O. saxosum C. H. Stirt. & Muasya and O. spissum C. H. Stirt. & Muasya. One new record for South Africa is confirmed: O. foliosum (Oliv.) C. H. Stirt. subsp. gazense (Baker f.) Verdc. We provide conservation status assessments under the IUCN criteria and also adopt a scheme capturing various levels of rarity (Rabinowitz rarity code). © 2017, The Board of Trustees of the Royal Botanic Gardens, Kew.
Ambiguous species delimitations and nomenclature are a major impediment for users of biodiversity information. This is more pronounced in plant lineages that have experienced recent and rapid diversification or where there is a tendency to lump many species under a general name. The papilionoid genus Psoralea L. is a young lineage (Pliocene, ca. 75 species) which has diversified rapidly within the South African fynbos biome and adjacent habitats. All species bearing 5–19 foliolate leaves were previously often lumped within the polymorphic species Psoralea pinnata, resulting in an unwieldy complex of at least 28 taxa, of which only eleven species are formally named. In this study we analyzed live specimens and populations in the field and herbarium collections, capturing their morphological and geographic diversity, for species delimitation. The results support the recognition of 25 distinct species, of which 14 are described here as new: P. azuroides; P. brilliantissima; P. elegans; P. floccosa; P. imminens; P. intonsa; P. ivumba; P.kougaensis; P. montana; P. muirii; P. rhizotoma; P. semota; P. sordida; and P. suaveolens. The taxon P. pinnata var. latifolia Harv. is raised to species rank, as P. latifolia comb. nov. The name P. pinnata sensu stricto is restricted here to a taxon with 5–9-leaflets extending from the Cape Peninsula to the Kogelberg mountains. We provide a key for the identification of all 25 species along with full descriptions, distribution maps and notes on their conservation status.
The pollen morphology of 22 Asian Vigna [subgenus Ceratotropis (Piper) Verdc.] species, including wild and cultivated taxa from India, was investigated with light microscopy and scanning electron microscopy. The quantitative data were analyzed by descriptive statistics and multivariate statistics. The pollen grains are prolate spheroidal in shape with equatorial diameter of 36.06– 116.33 μm and polar diameter of 36.31–120.96 μm in equatorial view. The small pollen dimensions were observed in Vigna hainiana, V. trilobata, and V. indica and the largest in V. vexillata. The pollen grains have reticulate-homobrochate and reticulate-heterobrochate types of pollen sculpture. The lumina are psilate or granulate with penta-hexagonal, penta-polygonal, and irregular shape. The muri are sinuous, straight, or narrow-straight. Pair group method using arithmetic averages analysis was used to divide the main pollen taxa into four groups based on pollen morphology. Statistically distinctive taxa were identified using principal component analysis. In the present investigation, the taxa studied demonstrated sufficient pollen polymorphism in their sizes, equatorial views, lumina shapes, and muri widths.
Subgenus Plecolobium C.H. Stirton of Lebeckia Thunb., described originally to accommodate the unusual species Lebeckia waltersii C.H. Stirton, is broadened to include five species and is raised to generic rank as Polhillia C.H. Stirton based on the species Polhillia waltersii (C.H. Stirton) C.H. Stirton. The following new combinations are made: Polhillia waltersii (C.H. Stirton) C.H. Stirton and P. connatum (Harv.) C.H. Stirton. P. pallens C.H. Stirton and P. canescens C.H. Stirton are described as new.
The vegetation of the Riversdale coastal plain was classified and described using Campbell’s (1985) approach. Data collected included a subset of Campbell’s structural and higher taxon characters, as well as dominant (>10% cover) species, which would enable the recognition of communities to at least the subseries level in his hierarchy. The classification was produced using the Braun-Blanquet method of table sorting. Twenty zonal communities, at various hierarchical levels, were recognized and mapped. Non-fynbos communities included Afromontane Forest, Eastern Forest and Thicket, Kaffrarian Succulent Thicket and Dune Thicket Series in the Forest and Thicket Group, and Renoster Shrubland. Fynbos communities were Mesotrophic Grassy Fynbos, three subseries of Asteraceous Fynbos (Mesotrophic, Dune and Oligotrophic), Azonal Restioid Fynbos, Wet Proteoid Fynbos, Dry Proteoid Fynbos and six types of Mesic Proteoid Fynbos. The vegetation types could all be integrated into Campbell’s Fynbos Biome mountain vegetation concepts and modifications based on work on the Agulhas plain. The mapped communities are adequate for conservation planning and comprise an essential descriptive basis for future studies. The data on Proteaceae cover corresponds well to that of the Restionaceae for Proteoid Fynbos — together the two families comprise the only groups which could be used for a classification without requiring extensive floristic studies.
The genus Dichilus DC. comprises five distinct species, namely D. gracilis Eckl. & Zeyh., D. lebeckioides DC., D. pilosus Conrath ex Schinz, D. strictus E. Mey. and D. reflexus (N.E. Br.) A.L. Schutte. The nomenclature, complete synonymy and typification, as well as a short diagnosis and the geographical distribution of each species are given.
Seven species of Aspalathus from South Africa are described as new. Two of the species are from the KwaZulu-Natal Province (Aspalathus dahlgrenii C.H.Stirt. & Muasya; A. spinifera C.H.Stirt. & Muasya), two are from the Eastern Cape Province (A. modesta C.H.Stirt. & Muasya; A. usnoides C.H.Stirt. & Muasya), and the other three from the Western Cape Province (A. eriocephaloides C.H.Stirt. & Muasya; A. eustonbrownii C.H.Stirt. & Muasya; A. nickhelmei C.H.Stirt. & Muasya). An identification key is provided to all of the species found in KwaZulu-Natal Province. New distribution records are added for, and conservation statuses re-assessed of the rare and little known species, Aspalathus macrocarpa Eckl. & Zeyh. and A. barbigera R. Dahlgren.
The major alkaloids of three species of Polhillia Stirton and three species of Argyrolobium Eckl. & Zeyh. have been identified. The presence of sparteine, lupanine, anagyrine and N-methylcytisine as major alkaloids in Polhillia and in the morphologically similar Argyrolobium brevicalyx Stirton indicates a direct phylogenetic link between Polhillia (Crotalarieae) and Argyrolobium (Genisteae). The data also supports the transfer of Melolobium involucratum (Thunb.) Stirton to Polhillia.
Rafnia Thunb. is a relatively poorly known papilionaceous genus of the tribe Crotalarieae, and is endemic to the fynbos region of the Western and Eastern Cape Provinces of South Africa, with one species extending into KwaZulu-Natal. Characters of the habit, leaves, inflorescences, flowers, pods and seeds are useful for distinguishing among the 19 species, and variations in morphological characters are discussed. A cladistic analysis of 26 characters produced a cladogram with two distinct groups, which form the basis of the division of Rafnia into two sections (described in the taxonomic part of the paper). Five new species, namely R. rostrata G.J. Campbell & B-E. van Wyk, R. vlokii G.J. Campbell & B-E. van Wyk, R. alata G.J. Campbell & B-E. van Wyk, R. inaequalis G.J. Campbell & B-E. van Wyk and R. globosa G.J. Campbell & B-E. van Wyk are described. Four species are divided into subspecies, seven of which are described for the first time. The nomenclature, synonymy and typification of the 31 taxa are presented, as are descriptions, illustrations and distribution maps.
A synopsis and key to South African species of Argyrolobium Eckl. & Zeyh. are presented. South Africa constitutes the centre of diversity for the genus and 47 species are recognised. Full synonymy and typification of the South African species are provided, with diagnostic characters, distribution maps and illustrations.
Many of the diverse floral characteristics used by taxonomists in assessing relationships among taxa represent adaptations to specific pollinators or pollinating methods. Therefore, the diversity of reproductive methods that occurs within a phylad has a strong influence on the number of taxa that are generally recognized in the phylad. Such evolutionary phenomena as convergence and adaptive radiation of floral patterns influence the taxonomic status of various phylads or the relationships that are seen among them. Incompatibility systems are generally unassociated with morphological distinctions, but are of practical importance in crossing programs designed to test the presence and nature of genetic isolation between species, since an unawareness of their existence may lead to erroneous taxonomic conclusions. Similarly, unilateral incompatibility is discussed in relation to certain practicalities in hybridizatíon programs. Morphological features associated with dioecism and heterostyly are disscussed as a generally overlooked source of potentially very useful taxonomic characters. The importance of adaptations to different pollinators as a basis of interspecific isolating mechanisms is stressed, as are the possible positive evolutionary (and taxonomic) consequences of a breakdown in this isolation. Floral and other characters associated with autogamy are discussed and examples are given where the relationships of autogamous taxa are uncertain because of their highly specialized reduced flowers. It is suggested that taxonomists should make an attempt to understand the reproductive methods of the plants with which they work, since such an understanding will strengthen the foundation upon which taxonomic judgments are made.
Taxonomic relationships amongst the predominantly southern African genera Dichilus DC., Lebeckia Thunb., Melolobium Eckl. & Zeyh., Polhillia Stirton and Wiborgia Thunb. of the tribe Crotalarieae and Argyrolobium Eckl. & Zeyh. of the tribe Genisteae have been studied. The most obvious similarity between these genera is the fusion of the calyx lobes into a trifid lower lip, or at least a tendency towards such a fusion. The morphology, chromosome numbers and alkaloids of some species and the geographical distribution of the genera have been investigated in an attempt to reach a better understanding of relationships. A tentative phylogenetic tree is presented which indicates that Argyrolobium is the sister group of Polhillia and that it should be referred to the tribe Crotalarieae. The concept of the genus Polhillia is broadened to include two anomalous species of Argyrolobium and Melolobium. Diagnostic characters of the genera are illustrated and discussed.
— We studied sequence variation in 16S rDNA in 204 individuals from 37 populations of the land snail Candidula unifasciata (Poiret 1801) across the core species range in France, Switzerland, and Germany. Phylogeographic, nested clade, and coalescence analyses were used to elucidate the species evolutionary history. The study revealed the presence of two major evolutionary lineages that evolved in separate refuges in southeast France as result of previous fragmentation during the Pleistocene. Applying a recent extension of the nested clade analysis (Templeton 2001), we inferred that range expansions along river valleys in independent corridors to the north led eventually to a secondary contact zone of the major clades around the Geneva Basin. There is evidence supporting the idea that the formation of the secondary contact zone and the colonization of Germany might be postglacial events. The phylogeographic history inferred for C. unifasciata differs from general biogeographic patterns of postglacial colonization previously identified for other taxa, and it might represent a common model for species with restricted dispersal.
The genus Psoralea L., comprising about 70 species, has its centre of diversity and endemism in the Greater Cape Floristic Region of South Africa. Species delimitation and identification in the genus are difficult. Many putative species are unpublished or known only by manuscript names. As a first step to address this problem this study reports on the taxonomy of the Psoralea aphylla complex — a distinct group of species characterised by either a complete absence of leaves, a reduction of the leaves into scales, or the occurrence of small filiform leaflets. Plants may be suffrutices, small to large shrubs, or trees. Morphological and ecological analyses of herbarium specimens and recent field collections distinguished ten species within the complex. Three species (P. aphylla L., P. filifolia Eckl. & Zeyh. and P. peratica C.H.Stirt.) are already published, while the seven other taxa have been known by manuscript names and are formalised in this paper (P. congesta C.H.Stirt. & Muasya; P. fleta C.H.Stirt.; P. gigantea Dludlu, Muasya & C.H.Stirt.; P. pullata C.H.Stirt.; P. ramulosa C.H.Stirt.; P. rigidula C.H.Stirt.; and P. usitata C.H.Stirt.). We provide a key for the identification of all ten species along with full descriptions, illustrations, distribution maps and some notes on the conservation statuses of the species.
The phylogenetic relationships of the genus Sorghum and related genera were studied by sequencing the nuclear ribosomal DNA (rDNA) internal transcribed spacer region (ITS). DNA was extracted from 15 Sorghum accessions, including one accession from each of the sections Chaetosorghum and Heterosorghum, four accessions from Parasorghum, two accessions from Stiposorghum, and seven representatives from three species of the section Sorghum (one accession from each of S. propinquum and S. halepense, and five races of S. bicolor). The maize (Zea mays) line, H95, and an accession from Cleistachne sorghoides were also included in the study. Variable nucleotides were used to construct a strict consensus phylogenetic tree. The analyses indicate that S. propinquum, S. halepense and S. bicolor subsp. arundinaceum race aethiopicum may be the closest wild relatives of cultivated sorghum; Sorghum nitidum may be the closest 2n=10 relative to S. bicolor, the sections Chaetosorghum and Heterosorghum appear closely related to each other and more closely related to the section Sorghum than Parasorghum; and the section Parasorghum is not monophyletic. The results also indicate that the genus Sorghum is a very ancient and diverse group.
Melolobium is a hitherto poorly known southern African papilionoid genus of the family Fabaceae. Although 20 species have previously been described, in the present revision, we recognize only 15 species. The genus appears to have close affinities with a number of other African genistoid genera (Adenocarpus, Argyrolobium, Dichilus and Polhillia), but can be distinguished by the often spiny habit, auriculate stipules and presence of glands (stalked and sessile) in most species of the genus. A cladistic analysis of morphological and anatomical characters resulted in a partially resolved cladogram in which virgate, non-spiny species are sister to the divaricately branched spiny group of species. The correct nomenclature, typification of names, descriptions, geographical distributions and a key to all the species of Melolobium are presented.
Psoralea involucsrata Thunb., a rare legume endemic to the Cape, was transferred to Argyrolobium by William Harvey. Recent evidence suggests that this is better placed in Melolobium in the tribe Crotalrieae and not in Argyrolobium (Genisteae). The affinities of this species are discussed and the new combination Melolobium involucratum (Thunb.) C.H. Stirton is made.
Although it is generally accepted that the tribe Genisteae has rather homogeneous pollen, we have found considerable variation in pollen size and morphology in Cytisus and related genera (Argyrocytisus and Chamaecytisus), which match taxonomic groups defined on morphological grounds. The results of Principal Component Analysis of pollen characteristics show the following: Cytisus Sect. Alburnoides is well-delimited, with the smallest pollen grains and the simplest pattern in the tectum, fossulate-perforate to perforate; No separation of C. villosus (Sect. Cytisus) from Sect. Alburnoides is observed; Cytisus Sect. Spartopsis, with the largest pollen grains and reticulate to reticulate-fossulate ornamentation, forms an isolated group; C. fontanesii (Sect. Heterocytisus) stands apart from other Cytisus species by its homogeneous ornamentation and the perforate instead of psilate-punctate margo. Thus, the pollen data supports its transfer to the separated genus Chronanthos; Pollen ornamentation and morphology also support the separation of Argyrocytisus battandieri and Chamaecytisus mollis from Cytisus.
South Coast Renosterveld is a small-leaved shrubland confined to the semi-arid and sub-humid coastal forelands of the southern and south-eastern Cape, South Africa. The flora of this vegetation type is biogeographically complex and includes numerous local endemics, many of which are geophytes. Much of the renosterveld is being converted to cereals and artificial pastures; conservation status is critical. There is evidence that the renosterveld has been derived in historical times from a Themeda triandra-dominated grassland. It is suggested that the reestablishment of a vigorous grassy sward would be the most effective long-term conservation strategy since utilisation would be compatible with conservation. Management models to improve the grazing status of South Coast Renosterveld should consider the biological attributes of key species. On the basis of phenological and other life history data on the dominant undesirable shrub (Elytropappus rhinocerotis, Metalasia muricata) and desirable grass (Themeda triandra) species, autumn is considered the optimum season of burn for the re-establishment of grassland.
A new species, Aspalathus crewiana is described and illustrated. It is closely similar to A. lenticula in the strongly rostrate keel petals and thorny leaflets, but differs in the subulate, spine-tipped bracts, bracteoles and calyx lobes, presence of a pseudo-peduncle and larger flowers. The new species, like A. lenticula, is placed in the Terminales group of A. subgenus Aspalathus. It is known from only two localities in the Western Cape where it was collected in Swartland Granite Renosterveld. Aspalathus L. is a large genus of the tribe Crotalarieae (Fabaceae) which comprises some 279 species. The genus was last studied in great detail by Rolf Dahlgren (1988) who recognised 278 species organized in a system of 5 subgenera and 34 informal groups. Subsequently, A. there-sae Cupido, was recently described from the Riviersonder-end Mountains (Cupido 2007). Aspalathus forms part of the ''Cape group'' of the Crotalarieae and is closely related to Wiborgia Thunb. and Wiborgiella Boatwr. & B.-E. van Wyk (Boatwright et al. 2008, 2010). Infrageneric relation-ships within Aspalathus are known to be complex. Many of the species are closely similar and often difficult to distinguish from each other (Dahlgren 1988). In addition, efforts to elucidate phylogenetic relationships within the genus based on DNA sequence data have failed due to low sequence variation, even when highly variable barcoding regions were used, and these remain largely unresolved (Edwards et al. 2008). In this paper, a new species from the Western Cape Province of South Africa is described. The species was first collected by Mrs Karen Marais of the Custodians of Rare and Endangered Wildflowers (CREW) at Brier Louw Nature Reserve (Western Cape Province, South Africa) in 2007, and subsequently also at Klipheuwel (Western Cape Province, South Africa) in 2009. The species is named in honour of CREW and the excellent work that they do to preserve the rare and endangered members of the South African flora.
The new species Polhillia ignota Boatwr. is described. This species is known only from two collections, one between Vredenburg and Saldanha and the other close to Porterville. The new species is most similar to P. obsoleta, which is known only from a few localities around Worcester, in its narrow, sericeous leaflets and flowers of equal size, but differs in its flattened mature leaves with larger leaflets (up to ±12 mm long), longer pseudo-peduncles (up to ±15 mm long), denser inflorescences (with up to four flowers), shorter pedicels (1–2 mm long) and non-auriculate wing-and keel petals.
Evidence from the internal transcribed spacer (ITS) of nuclear ribosomal DNA and plastid rbcL data revealed that the genus Lebeckia Thunb. as currently circumscribed may not be monophyletic. These analyses, combined with morphological and anatomical data, showed that the genus could be divided into three genera: (1) Lebeckia sensu stricto (L. section Lebeckia); (2) Calobota [L. section Calobota (Eckl. and Zeyh.) Benth. and L. section Stiza (E.Mey.) Benth.] including the monotypic, North African genus Spartidium Pomel; (3) a new genus, Wiborgiella [L. section Viborgioides Benth., together with L. inflata Bolus, L. mucronata Benth. and Wiborgia humilis (Thunb.) Dahlgr.]. The reinstatement of the genus Calobota Eckl. and Zeyh. is proposed and Wiborgiella Boatwr. and B.-E. Van Wyk described as new. Synopses of the genera Calobota and Wiborgiella, including nomenclature, synonymy, descriptions and diagnostic characters are presented.
Tribe Crotalarieae is a large and diverse group of papilionoid legumes that largely occur in Africa. A systematic study of generic relationships within the tribe was undertaken using nucleotide sequences from the internal transcribed spacer (ITS) of nuclear ribosomal DNA, the plastid gene rbcL, and morphological data. The Crotalarieae are supported strongly as mortophyletic and sister to the tribe Genisteae. Lebeckia, Lotononis, and Wiborgia are all paraphyletic in the molecular analyses and morphological data support the division of Lebeckia into three more natural genera (one of which includes the monotypic North African Spartidium). Four major lineages were identified within the tribe based on sequence data: the "Cape" group, comprising Aspalathus, Lebeckia, Rafnia, Spartidium, and Wiborgia; the Lotononis group, comprising Lotononis pro parte, Pearsonia, Robynsiophyton, and Rothia; a group comprising Lotononis section Leptis, L. section Listia, and allies; and the Crotalaria group, comprising Bolusia, Crotalaria, and Lotononis hirsuta (Lotononis section Euchlora). Morphological analysis yields a similar topology, except that Lotononis is monophyletic if L. hirsuta were excluded. When the molecular and morphological data sets are combined, the same major clades are retrieved as in the molecular analysis, with the notable exception that Lotononis and Lebeckia sense stricto are supported as monophyletic. The results from this study have important implications for the classification of the tribe Crotalarieae and present an important step towards a natural and phylogenetic generic classification for the tribe.
Petal structure and the distribution of pigments in petals were studied in relation to the functional anatomy of petals and the ways in which petals absorb and reflect light. We examined 201 species from 60 angiosperm families. Anthocyanins, betalains and ultraviolet-absorbing flavonoids were normally confined to the epidermal cells, occurring in solution in the vacuole; carotenoids were found in the epidermis and in smaller quantities in the mesophyll, normally in chromoplasts. In a few species, mainly blue-flowered members of the Boraginaceae and Liliaceae-Scilleae, anthocyanins were confined to the mesophyll.
Six basic kinds of petal epidermis anatomy were found, sometimes in combination; papillate (112 species) and multiple-papillate (13 species), in which the conical-papillate form of the cells traps incident light and scatters emergent light, with surface striations aiding these functions in many cases; reversed-papillate (4 species), multiple reversed-papillate (29 species), lenticular (32 species) and flat (11 species), all with surface striations in some cases. Light is usually reflected from petals mainly by an aerenchymatous unpigmented reflective mesophyll; in certain species this is replaced by a reflective layer of starch grains in the upper mesophyll.
Molecular evidence presented here, from the literature and from this study, provide new insights into the systematics of the Genisteae s.s. Within this tribe, the evolutionary history of Ulex is investigated using phylogenetic analyses of two non-coding nuclear (ITS nrDNA) and plastid (trnL-trnF) sequences. Ulex represents a natural group, which is derived from within the Genista-Cytisus complex. A close relationship between Ulex and Stauracanthus is strongly supported by molecular data. Ulex appears to have evolved into two main lineages, which arose from a common diploid ancestor. One is represented by a single extant diploid species, U. micranthus, which is endemic in central Portugal. The second group includes all the remaining Euro-African diploid and polyploid taxa. The lack of resolution among the latter and their very weak molecular divergence are suggestive of a recent and rapid diversification of the gorses. The trnL-trnF sequence data also support Lupinus as a monophyletic group within Genisteae, that is distinct from the Cytisus-Genista complex.
The South Coast Renosterveld has been fragmented extensively by agriculture. The extent of this fragmentation in terms of overall habitat loss, fragment sizes and fragment numbers has not been described previously, thereby limiting the development of conservation strategies for this vegetation type. Patterns of renosterveld loss in three sectors along a west–east gradient were described using LANDSAT imagery and a Geographical Information System-based program (FRAGSTATS) for spatial pattern analysis. These patterns were then correlated with rainfall and topography measures, which are indicators of agricultural potential. Over 80% of the South Coast Renosterveld has been cultivated. Fragmentation levels increased significantly from east to west, with 33% of natural vegetation remaining in the east and only 4% in the west. Topographical variables were the strongest predictors of patterns of renosterveld loss, with fragments being largely confined to slopes too steep for ploughing; they therefore face little risk of future cultivation. These results have implications for conservation planning options for the South Coast Renosterveld. There is the potential for large reserves in the east, as well as corridor reserves along major river valleys, but for only small, isolated reserves in the west.
Phylogenetic relationships within the complex genus Lupinus are estimated from internal transcribed spacer (ITS) sequences of the nuclear ribosomal DNA repeat. The molecular data supports Lupinus as a distinct monophyletic group within the tribe Genisteae. Different geographical lineages are revealed within Lupinus, which are each restricted to either the Old or the New World. In the New World, the ITS data support an eastern-western geographic disjunction of the lupines and the recognition of some well-supported clades. In the Old World, almost all the previously recognized taxa are taxonomically well differentiated. The homogeneous African rough-seeded lupines, Scabrispermae, are strongly supported as a monophyletic group, which is distinct from the diverse and heterogeneous circum-Mediterranean smooth-seeded ones. The latter appear to have evolved as two lineages, in which are revealed some intersectional relationships. Also ITS data allow the assessment of the phylogenetic position of the newly discovered species, L. anatolicus (in the Old World) and L. jaimehintoniana (the Mexican tree lupin). The ITS phylogeny suggests a rapid initial radiation of the lupines subsequent to their divergence from a common ancestor. Moreover, the results indicate that the annual and perennial habits have evolved many times in Lupinus and suggest a role for generation time in affecting the evolutionary history of lupines. Data on adaptive processes and character evolution are re-examined and discussed in the light of the ITS phylogeny.