bluuebunny/crossref_metadata_2025_split huggingface dataset:
Intraspecifíc variability in <i>Alloteropsis semialata</i> (R. Br.) Hitchc.
Authors: Frean M. L. , Barrett D. R. , Ariovich D. , Wolfson M. , Cresswell C. F. 
Published: July 2015

Intraspecific variability in Alloteropsis semialata (R. Br.) Hitchc. is shown ultrastructurally with particular regard to the structure of the bundle sheath and the development of the dimorphic chloroplasts in both the C3 and C4 forms of this species. A. semialata is known to possess two distinct anatomical forms — Kranz and non-Kranz — within one species and occurring within a single ecological niche. Kranz and non-Kranz anatomy is known to be correlated with C3 and C4 physiology respectively. Transverse sections of leaf portions taken at midsheath, at the ligule and at midlamina show plastids with different morphologies at different ontogenetic stages. Plastid form is related to the stage of development, the influence of light on the emerging leaf and the C3 or C4form of A. semialata. Stages from amyloplast to chloroplast are investigated with regard to fine structure. Leaf transverse sections are examined microscopically and formation of new bundles, chiefly in the lamina is traced. Differences in anatomy and distribution of vascular bundles are more evident in the lamina than in the colourless leaf sheath. Both C3 and C4 forms of A. semialata are found to show chloroplast dimorphism in vascular bundle sheath and mesophyll cells. This is shown to differ in the two forms. The specialized chloroplasts of the Kranz sheath are shown to develop in the inner or mestome sheath, and not in the parenchyma sheath as in some other members of the Kranz Panicoideae. Features of A. semialata, such as the double bundle sheath, granal chloroplasts and large numbers of mitochondria in bundle sheath cells, in the C4 form, question the current classification of this grass as a malate former.
Classification of embryo sacs in the Eragrostis curvula Complex
Authors: Vorster T. B. , Liebenberg H. 
Published: July 2015

At each of 17 collecting points between Johannesburg and Brits in the Transvaal, three plants which belong to the Eragrostis curvula Complex were collected and studied. A total o f 3 902 embryo sacs was examined in this sample. Of the embryo sacs examined, 3 306 were apomictic by means of diplospory, whereas 99 were sexual monosporic Polygonum-type embryo sacs. One hundred and nineteen embryo sacs were abnormal or divergent, and 378 were degenerated. There are indications that seasonal climatic fluctuations may be responsible for embryo sacs developing abnormally or degenerating. Simple and multiple correlations confirmed that sexual embryo sacs usually do not develop abnormally or degenerate during the later developmental stages. This finding lends credence to both the system of classification of individual embryo sacs and to the validity of the estimate of the proportion of sexuality of the plants sampled at each sampling point.
The development from kinetic coefficients of a predictive model for the growth of Eichhornia crassipes in the field. IV. Application of the model to the Vernon Hooper Dam — a eutrophied South African impoundment
Authors: Musil C. F. , Breen C. M. 
Published: July 2015

A model developed for Eichhornia crassipes (Mart .) Solms was used to identify the limiting nutrient in the Vernon Hooper Dam and to predict population sizes, yields, growth rates and frequencies and amounts of harvest under varying conditions of nutrient loading and climate. Predicted data were used to evaluate the effectiveness of harvesting measures currently being employed for controlling both nutrient inputs and the population size in this impoundment. Predictions o f the population size, before harvesting was initiated, generally compared favourably with th a t estimated visually. Predictions of the quantities of P that could be removed daily by a 20 ha population indicate that such a population in the impoundment could reduce P concentrations in the epilimnion during summer stratification to levels limiting for algae. This may explain the observed reduction in algal concentrations since the introduction of harvesting. Estimates of the amounts and frequencies of harvest required to contain the predicted potential yields of a 20 ha population indicate that 100 metric tonnes of fresh water hyacinths harvested daily from the impoundment, under present conditions of reduced nutrient loading, are adequate during winter, but not during summer.
Studies in the genus <i>Riccia (Marchantiales) from southern Africa. 2. A new species of the section <i>Pilifer</i>: <i>R. sarcosa</i>
Authors: Volk O. H. , Perold S. M. 
Published: July 2015

Riccia sarcosa Volk Perold, a new species endemic to southern Africa is described. This species belongs to the section Pilifer Volk (1983), which now comprises 8 species characterized by the dorsal epithelium consisting of loose cell pillars. R. sarcosa is recognized by the distinct white margins of the thallus, by inconspicuous hyaline scales that do not extend above the thallus margins and by the spore ornamentation consisting of round, deep-set areolae or foveae.
The biomes of the eastern Cape with emphasis on their conservation
Authors: Lubke R. A. , Everard D. A. , Jackson Shirley 
Published: July 2015

The four major phytochoria of southern Africa, the Cape. Tongoland-Pondoland. Karoo-Namib and Afromontane regions, converge in the complex transition zone of the eastern Cape. The area is rich in species and communities with a complex vegetation in which are represented all the major vegetation formations of southern Africa — Cape Fynbos. Cape Transitional Shrublands, Subtropical Thicket. Karoo, Savanna, Afromontane Forest, Grasslands and Littoral Strand Vegetation. Our results support previous findings that, although species-rich and of great diversity, the flora has fewer endemics (205 or 5,6%) than the Cape (73%) or Karoo-Namib (35%). The communities with the largest proportion of endemics (30%), and threatened plants (18%) are those of the Subtropical Thicket. On the basis of these data and an index of conserv ation status, the Subtropical Thicket was determined to be highest on the priority list for conservation in the eastern Cape. Subtropical Thicket is being cleared at an increasing rate and is most vulnerable due to changing farming practice.
Bibliography of <i>Fusarium</i> (Fungi: Hyphomycetes) in South Africa, 1945-1985
Authors: Marasas W. F. O. , Lamprecht Sandra C. , Van Wyk P. S. , Anelich R. Y 
Published: July 2015

A taxonomic study of the genus Fusarium in South Africa was published by Doidge in 1938. A record of all the fungi, including Fusarium, known to occur in South Africa, and of the literature concerning them until the end of 1945, was compiled by Doidge in 1950. The present bibliography attempts to provide an index to all the literature on Fusarium in South Africa published after 1945 until the end of 1985. An alphabetical list of Fusarium species is provided and the hosts and/or substrates from which each species has been recorded are listed alphabetically together with references to the literature cited. A separate alphabetical list of hosts and substrates together with the Fusarium species recorded on each is also included.
Synopsis of the genus <i>Salix</i> (Salicaceae) in southern Africa
Authors: Immelman K. L. 
Published: July 2015

One species of Salix, S. mucronata Thunb. (=S . subserrata Willd.), with five subspecies, is recognized as indigenous to the southern African region. Problems of delimitation in the genus in southern Africa are discussed, and a key to the indigenous and exotic taxa is presented. The synonymy of the subspecies is presented, with leaf silhouettes and a distribution map of each. The following new combinations are made: S. mucronata subsp. hirsuta (Thunb.) Immelman, S. mucronata subsp. capensis (Thunb.) Immelman, 5. mucronata subsp. woodii (Seemen) Immelman and S. mucronata subsp. wilmsii (Seemen) Immelman.
The naturalized species of <i>Lupinus</i> (Fabaceae) in southern Africa
Authors: Stirton C. H. 
Published: July 2015

Four species of Lupinus have become naturalized in southern Africa: L. consentinii Guss., L. angustifolius L., L. pilosus Murray and L. luteus L. Their morphological variation and geographical distribution is discussed and a key is provided.
The <i>Cheilanthes hirta</i> complex and allied species (Adiantaceae/Pteri­daceae) in southern Africa
Authors: Jacobsen W. B. G. , Jacobson N. H. G 
Published: July 2015

The very variable complex of plants until now ascribed to Cheilanthes hirta Swartz, together with some derived or allied species, is investigated. The type of the species as established by N. C. Anthony (1984), is accepted. Three new varieties are distinguished: Cheilanthes hirta Swartz var. brevipilosa W. N. Jacobsen, var. inferacampestris W. N.Jacobsen and var. nemorosa W. N. Jacobsen. One new form of Cheilanthes hirta var. brevipilosa W. N. Jacobsen is recognized: forma waterbergensis W. N. Jacobsen. Var. laxa Kunze (1836) is given the new status of forma: Chei­lanthes hirta var. brevipilosa W. N. Jacobsen forma laxa (Kunze) W. N. Jacobsen. Three allied species are discussed and included in the key to all taxa mentioned. Taxa are described and information given includes notes on distribution and ecology. Special attention is paid to spore morphology. Most taxa are illustrated by a habit photo, and all by line drawings and scanning electron micrographs (SEM) of the spores. Possible evolutionary conclusions, particularly on the nature of the spores and on frond dimensions in relation to geographical distribution and climate are discussed.
Leaf anatomy of the South African Danthonieae (Poaceae). XVIII. <i>Centropodia mossamedensis</i>
Authors: Ellis R. P. 
Published: July 2015

The leaf blade anatomy of Centropodia mossamedensis (Rendle) T. A. Cope [= Asthenatherum mossamedense (Rendle) Conert] is described and illustrated. This description is based on freshly fixed material and confirms that this species has Kranz anatomy with the C4 photosynthetic pathway. The anatomy differs little from that of C. glauca and both undoubtedly belong to the same genus which is justifiably separated from the other danthonoid genera.
Taxonomy and leaf anatomy of the genus <i>Ehrharta</i> (Poaceae) in southern Africa: the Ramosa group
Authors: Gibbs Russel G. E. , Ellis R. P. 
Published: July 2015

The Ramosa species group in the genus Ehrharta is distinguished morphologically by small spikelets with sterile lemmas similar to each other, with tips rounded, truncate or mucronate, with sides glabrous, scabrous or shortly hairy, and with bases appendaged and usually bearded. The rectangular intercostal long cells with sinuous walls, the dome-shaped stomata with a raised rim surrounding the pore aperture, the absence of epicuticular wax and the microhairs without a tapering distal cell are diagnostic anatomically. The Ramosa group is composed of two species: E. ramosa (Thunb.) Swartz subsp. ramosa, subsp. aphylla (Schrad.) Gibbs Russell and E. rehmannii Stapf subsp. rehmannii; subsp. filiformis (Nees) Gibbs Russell; subsp. subspicata (Stapf) Gibbs Russell. All taxa are linked by intermediates to one or two others in the group. The closest relationship of the Ramosa group is to the Calyeina species group, on the basis of both morphological and anatomical characters.
Leaf anatomy of the South African Danthonieae (Poaceae): XIX. The genus <i>Prionanthium</i>
Authors: Ellis R. P. 
Published: July 2015

The leaf blade anatomy of Prionanthium dentatum (L. f.) Henr., P. ecldonii (Nees) Stapf and P. pholiuroides Stapf is described and illustrated. The transectional anatomy is non-Kranz with diffuse chlorenchyma. The adaxial epidermis has dome-shaped stomata, dumbbell-shaped to nodular silica bodies and elongated microhairs. The three species differ in the presence or absence of macrohairs, abaxial stomata and marginal linear, sessile glands. The latter character is shared with Pentaschistis triseta (Thunb.) Stapf and its allies, and relationships with Pentaschistis are indicated rather than with any other extant arundinoid genus.
Studies in the genus <i>Riccia</i> (Marchantiales) from southern Africa. 16. <i>R. albomarginata</i> and <i>R. simii</i>, sp. nov.
Authors: Perold S. M. 
Published: July 2015

A description of Riccia albomarginata Bisch. ex Krauss, augmented with the aid of new collections which most closely match the relevant fragments of the type material, is presented. The type collection comprises two species. The fragments that I consider to be in closest agreement with Krauss’s protologue are selected as lectotype. As far as could be established the rest of the type material is probably referable to R. concava Bisch. As previously mentioned by Perold (1989b), Sim (1926) and subsequent authors had applied the name * R. albomarginata' to a different taxon. This taxon, R. albomarginata auct. non Bisch., is now described and illustrated as R. simii, sp. nov. Its distribution and ecology are also noted.
Kranz distinctive cells in the culm of ArundineUa (Arundinelleae; Panicoideae; Poaceae)
Authors: Sanchez Evangelina , Arriaga Mirta O. , Ellis Roger P. 
Published: July 2015

The transectional anatomy of photosynthetic flowering culms of Arundinella berteroniana (Schult.) Hitchc. Chase and A. hispida (Willd.) Kuntze from South America and A. nepalensis Trin. from Africa is described and illustrated. The vascular bundles are arranged in three distinct rings, the outermost being external to a continuous sclerenchymatous band. Each of these peripheral bundles is surrounded by two bundle sheaths, a complete mestome sheath and an incomplete, outer, parenchymatous Kranz sheath, the cells of which contain large, specialized chloroplasts. Kranz bundle sheath extensions are also present. The chlorenchyma tissue is also located in this narrow peripheral zone and is interrupted by the vascular bundles and their associated sclerenchyma. Dispersed throughout the chlorenchyma are small groups of Kranz distinctive cells, identical in structure to the outer bundle sheath cells. No chlorenchyma cell is. therefore, more than two cells distant from a Kranz cell. The structure of the chlorenchyma and bundle sheaths indicates that the C4 photosynthetic pathway is operative in these culms. This study clearly demonstrates the presence of the peculiar distinctive cells in the culms as well as in the leaves of Arundinella. Also of interest is the presence of an inner bundle sheath in the vascular bundles of the culm whereas the bundles of the leaves possess only a single sheath. It has already been shown that Arundinella is a NADP-me C4 type and the anatomical predictor of a single Kranz sheath for NADP-me species, therefore, either does not hold in the culms of this genus or the culms are not NADP-me. This is only the second reported breakdown of this association between MS anatomy and the NADP-me biochemical C4 type.
Studies in the genus <i>Riccia</i> (Marchantiales) from southern Africa. 18. New species in section <i>Pilifer</i> from the NW Cape: <i>R. furfuracea</i>, <i>R. vitrea</i> and <i>R. namaquensis</i>
Authors: Perold S. M. 
Published: July 2015

Another three new species of Riccia in section Pilifer Volk are described from Namaqualand, namely R. furfuracea, R vitrea and R. namaquensis. There are certainly more undescribed species present in that region, but species from there are often very difficult to distinguish: almost all have hyaline scales, the free-standing dorsal cell pillars need to be examined in living plants and the spore ornamentation is quite variable.
New taxa, new records and name changes for southern African plants
Authors: De Wet B. C. , Germishuizen G. , Schrire B. D. , Jordaan M. , Pienaar B. J. , Welman W. G. , Reid C. , Van Wyk C. M. , Fish L. , Immelman K. L. , Van Rooy J. , Perold S. M. , Taussig J. , Barker N. P. 
Published: July 2015

Additions and alterations to the inventory of approximately 25 000 southern African plant taxa are reported for the period from February 1989 to February 1990. In this period, a total of 890 alterations have been recorded. These changes result from the continual surveying of taxonomic literature received by the library of the National Botanical Institute.
<i>Kamiesbergia</i>, a new monotypic genus of the Amaryllideae-Strumariinae (Amaryllidaceae) from the north-western Cape
Authors: Snijman D. A. 
Published: July 2015

Kamiesbergia Snijman is a new monotypic genus from raised granite outcrops in the north-western Cape. A member of the subtribe Strumariinae of the Amaryllideae, it is most closely related to Hessea Herb, and Namaquanula D. U. Miiller-Doblies. The dissimilar inner and outer stamens, the uniquely club-shaped inner filaments and the novel insertion of the filament in the proximal quarter of the anther connective are the main apomorphies of the genus. The number of rare and monotypic genera of Amaryllidaceae in this region is comparable to that of Andean South America.
Cyanophyceae associated with mangrove trees at Inhaca Island, Mozambique
Authors: Siva S. M. F. 
Published: July 2015

A survey of the Cyanophyceae associated with two of the five mangrove trees and their associated Bostrychieta at Inhaca Island, Mozambique, was undertaken. Sixteen taxa belonging to 12 genera were identified. Of these, six taxa were new records for Mozambique, three at generic and three at specific level. Thirteen taxa of Cyanophyceae were found growing on Avicennia marina (Forssk.) Vierh. and four on Ceriops tagal (Perr.) C.B. Robinson. Chamaecalyx leibleiniae (H. Reinsch)Komarek Anagnostidis was the only Cyanophyceae to occur on both species of tree.
Invasive alien woody plants of the northern Cape
Authors: Henderson L. 
Published: July 2015

The frequency and abundance of invasive alien woody plants were recorded along roadsides and at watercourse crossings in 31% (90/286) of the quarter degree squares in the study area. The survey yielded 23 species of which the most prominent invaders were Prosopis spp. The most prominent remaining species were: Opuntia ficus-indica, Nicotiana glauca and Melia azedarach. The greatest abundance and diversity of alien invader plants were recorded near human settlements. More than half of the total recorded species have invaded perennial riverbanks. The episodic Molopo and Kuruman Rivers have been invaded almost exclusively by Prosopis spp., which in places have formed extensive stands.
The occurrence in southern Africa of the hepatic, <i>Symphyogyna</i> <i>brasiliensis</i> (Pallaviciniaceae)
Authors: Perold S. M. 
Published: July 2015

In Magill Schelpe (1979) Symphyogyna lehmanniana is confirmed as occurring in southern Africa. Subsequently, however. Grolle (1980) reported that this name, which has been applied to a liverwort widespread in Africa, is a synonym of S. brasiliensis. To draw attention to this synonymy, a description of S. brasiliensis, illustrated with photographs, is given here, as well as an account of its distinguishing features and its distribution.
Morphology, evolution and taxonomy of <i>Wachendorfia</i> (Haemodoraceae)
Authors: Helme N. E. , Linder H. P. 
Published: July 2015

Wachendorfia Burm. is a small genus endemic to the Cape Floral Region. Pour species are recognised in this study. Two species were originally described by Burman in 1757 and these were followed by numerous other descriptions of what is essentially one very variable species (W. paniculaia Burm.). This variation is discussed and reasons are given as to why the recognition of formal infraspecific taxa is inappropriate. Formal taxonomic descriptions, distribution maps and a key to the species are provided. Rhizome morphology, leaf anatomy and pollen and seed coat structures were investigated and illustrations are provided. A cladogram was inferred and this is consistent with an ecological speciation model for the genus. The two species with the most restricted distribution (W. brachyandra W.F. Barker and W. pamfiora W.F. Barker) are considered to be the most recently evolved. Features of systematic and ecological interest (e.g. floral enantiomorphy) are discussed.
Panicum simulans (Paniceae, Poaceae), a new species from southern Africa and its leaf anatomy
Authors: Smook L. , Ellis R. P. 
Published: July 2015

Panicum simulans Smook from northern Namibia is formally described. The morphology and leaf blade anatomy in transection and surface view, as observed under the light microscope, are described. The species is compared to others with which it has been confused in the past. P. simulans can be readily distinguished from P. novemnerve Stapf and P schinzii Hack, on the basis of both anatomical and morphological characters such as the venation of the lower glume and the photosynthetic anatomy, which is of the NAD-me subtype of the C4 photosynthetic pathway. On this basis it appears that P simulans is closely allied to the P. coloratum L. group of species and should be placed in section Panicum of subgenus Panicum.
Synopsis of the genus <i>Brachylaena</i> (Asteraceae) in southern Africa
Authors: Cilliers S. S. 
Published: July 2015

A synopsis of the southern African representatives of the genus Brachylaena R. Br. (Asteraceae) is presented, in which seven species and two subspecies are recognized. B. uniflora Harv. is placed in synonymy with B. discolor subsp. transvaalensis (Phill. Schweick.) J. Paiva and the division of subsp. discolor in two varieties is not accepted. Descriptions, synonymy, voucher specimens, distribution maps, line drawings and keys to the species and subspecies are given.
Nomenclatural changes and additions to the genus <i>Ophioglossum</i> in Africa (Ophioglossaceae: Pteridophyta)
Authors: Burrows J. E. , Edwards T. J. 
Published: July 2015

Recent research has necessitated a review of the nomenclature of the genus Ophioglossum in Africa. This paper establishes a new species, O. caroticaule J. E. Burrows, a new subspecies, O. vulgatum L. subsp. africanum Pocock ex J. E. Burrows, and a change in status, O. latifolium (Prantl) J.E. Burrows (basionym: O. gomezianum var. latifolium Prantl). Lectotypification is provided for O. gracillimum Welw. ex Hook. Bak., O. lusoafricanum Welw. ex Prantl, O. latifolium (Prantl) J.E. Burrows, and 0. rubellum Welw. ex A. Braun. Nomenclatural problems in O. lancifolium Presl are discussed.
ASPHODELACEAE/ALOACEAE: WAS <i>GASTERIA NITIDA</i> VAR. <i>ARMSTRONGII</i> VALIDLY PUBLISHED?
Authors: Smith G. F. , Van Wyk B-E. , Van Jaarsveld E. J. 
Published: July 2015

WAS GASTERIA NITIDA VAR. ARMSTRONGII VALIDLY PUBLISHED?
A taxonomic re-assessment of <i>Ammocharis</i> herrei and <i>Cybistetes longifolia</i> (Amaryllideae: Amaryllidaceae)
Authors: Snijman D. A. , Williamson G. 
Published: July 2015

The infructescence of the poorly known Ammocharis herrei F.M. Leight. is similar to that which is diagnostic for Cybistetes longifolia (L.) Milne-Redh. Schweick. In the absence of distinct morphological differences A. herrei is placed into synonymy under C. longifolia. Plants of the amplified C. longifolia have fewer, large seeds in Namaqualand and the Richtersveld and smaller, more numerous seeds in the Western Cape. This pattern is postulated to reflect divergent strategies of resource allocation in different habitats. It is suggested that the infructescence of C. longifolia. a highly derived structure suited to tumbling, evolved from the unspecialised condition in Ammocharis as an adaptation to the high winds of southwestern Africa.