Species Of Encephalartos Research Articles

Uncovering the cycad taxa ( Encephalartos species) traded for traditional medicine in Johannesburg and Durban, South Africa

The bark and stems of Encephalartos species are used for traditional medicine across South Africa, and some species are traded in traditional medicine markets. The absence of characteristic plant parts such as leaves and cones in the chopped up market material presents a major challenge to the identification of the species traded. In this study, South Africa's two largest traditional medicine markets, Faraday in Johannesburg and Warwick in Durban, were surveyed to ascertain the source areas and species of Encephalartos in trade. Samples of stem fragments were purchased from vendors, identified to probable species and their stem diameter size class distributions determined using a specially designed size class chart. Species identification was undertaken by comparing trader citations of harvesting areas with the distributions of Encephalartos species in the province of KwaZulu-Natal (since all the specimens originated from KZN). The species most commonly recorded in the markets were identified as Encephalartos natalensis, E. villosus and E. ghellinckii; small quantities of what are likely to be E. ferox and E. senticosus were also observed. Following this study, the total number of South Africa's 37 Encephalartos species recorded as being used for traditional medicine is 25. Stem diameter size class distributions showed that most stem fragments came from sub-adult and adult cycads. Large arborescent species appear to be harvested by removing bark strips from adult individuals, while smaller arborescent and subterranean species are harvested by removing the entire plant. Regression relationships between stem tissue type and stem diameter for E. natalensis and E. ghellinckii indicate a strong, positive linear relationship of leaf base length and pith radius with stem diameter. Overall, this is the first known study that attempts to identify the cycad species traded in South African traditional medicine markets in conjunction with the size classes of the specimens in trade.

Foliicolous microfungi occurring on Encephalartos

Species of Encephalartos, commonly known as bread trees, bread palms or cycads are native to Africa; the genus encompasses more than 60 species and represents an important component of the indigenous African flora. Recently, a leaf blight disease was noted on several E. altensteinii plants growing at the foot of Table Mountain in the Kirstenbosch Botanical Gardens of South Africa. Preliminary isolations from dead and dying leaves of E. alten-steinii, E. lebomboensis and E. princeps, collected from South Africa, revealed the presence of several novel microfungi on this host. Novelties include Phaeomoniella capensis, Saccharata kirstenboschensis, Teratosphaeria altensteinii and T. encephalarti. New host records of species previously only known to occur on Proteaceae include Cladophialophora proteae and Catenulostroma microsporum, as well as a hyperparasite, Dactylaria leptosphaeriicola, occurring on ascomata of T. encephalarti.

Genetic variability and species identification within Encephalartos using Random Amplified Polymorphic DNA (RAPD) markers

Encephalartos is the second largest genus of the living cycads with 65 species and 2 sub-species. Most species of Encephalartos are morphologically very similar and therefore could benefit from additional tools for their correct identification. The present study aimed to study the genetic variability within 22 species of the genus Encephalartos using Random Amplified Polymorphic DNA (RAPD) markers. Seventeen RAPD primers were used to carry out the present study. These primers were used to amplify the genomic DNA of the 22 species of Encephalartos. Amplification products ranged in size from 250 bp to 2500 bp, while in number they ranged from 1 to 12. A total of 186 reproducible bands were scored of which 166 (88%) were polymorphic and 20 (12%) were monomorphic and 3 were unique bands. Within the species of Encephalartos a high degree of genetic variability exists, as the similarity index value ranged from 0.440 to 0.833. The lowest value of 0.440 was between E. altensteinii and E. transvenosus, while E. bubalinus and E. princeps exhibited maximum values (0.833), indicating their close genetic relatedness. Two primers generated unique bands in three species of Encephalartos, which could assist to identify these species at the molecular level. Three unique bands, OPC-02 ∼ 300 , OPC-02 ∼ 500 and OPE-01 ∼ 2300 bp, were generated for E. gratus, E. hilderbrandtii and E. inopinus, respectively. The results suggest considerable potential of the RAPD approach for correct genetic identification of individual species as well as an efficient way of fraud prevention. Genetic variability within the species of Encephalartos can be ascertained using these primers.

Molecular Relationships in Encephalartos (Zamiaceae, Cycadales) Based on Nucleotide Sequences of Nuclear ITS 1&2, Rbcl, and Genomic ISSR Fingerprinting

The cycad genus Encephalartos is restricted to Africa and is threatened with extinction in most of its range. Total DNA was extracted from 51, i.e., 78 %, of the described species of Encephalartos. The accessions were sampled from the furthest western occurrence of the genus in Nigeria, via Sudan and Uganda, to southern South Africa. The sequences of nuclear ribosomal internal transcribed spacer regions 1 and 2 (ITS 1&2), the chloroplast encoded rbcL gene, and ISSR genomic fingerprinting were employed to resolve the molecular history and the relationships within the genus. Sequence alignment, as well as ISSR fingerprinting, data show low genetic variation among all analysed accessions, indicating diversification within the Pliocene/Pleistocene. ITS 1&2 data agree well with morphological and geographical characters and resolved three major genetic clusters with overlapping distribution ranges in eastern South Africa. This area, that contains the largest diversity of genotypes of Encephalartos, may have served as a Pliocene/Pleistocene refugium.

Phylogeny of Encephalartos: Some Eastern Cape Species

I. Abstract A group of eight species of Encephalartos, comprising E. altensteinii, E. arenarius, E. horridus, E. latifrons, E. lehmannii, E. longifolius, E. princeps, and E. trispinosus, from the Eastern Cape Province of South Africa, was studied by analysis of iso-enzymes, ribosome DNA, and ITS 1 and 2 genes. The reason for this investigation was that the morphology of the vegetative and reproductive parts, though very distinctive in this geographical region, do not correlate, and it was hoped that molecular data would elucidate evolutionary relationships. The three sets of molecular data were found to agree to a remarkable degree. It was concluded that the vegetative morphology was misleading but that the cone characteristics agree with molecular data and provide insight into the interrelationships of these species. Thus, E. princeps was concluded to be relatively remotely related to the vegetatively similar E. lehmannii, and E. arenarius is not at all close to E. latifrons even though the two species a...

Allozyme and DNA sequence comparisons of nine species of Encephalartos (Zamiaceae).

Phylogenetic relationships between Encephalartos altensteinii Lehmann, E. arenarius R.A. Dyer, E. horridus (Jacquin) Lehmann, E. latifrons Lehmann, E. lehmannii Lehmann, E. longifolius (Jacquin) Lehmann, E. princeps R.A. Dyer and E. trispinosus (Hooker) R.A. Dyer were studied, using E. ferox Bertoloni f. as outgroup. Three continuous and one discontinuous buffer systems were used and gene products of 14 enzyme coding loci were examined by horizontal starch gel-electrophoresis. Genetic variation was studied in a cultivated population of E. lehmannii and the average heterozygosity value for this population is 13.5%, which falls within the range reported for other cycad species. Fixed allele differences between the species studied was not found at any of the loci studied, which suggest that these species are closely related. DNA sequence analysis of rbcL and ITS 1 & 2 genes (1428 and 895 basepairs, respectively) confirmed the close genetic relationships between these taxa. According to ITS and rbcL sequences E. altensteinii and E. princeps are sibling taxa which form a sister group to E. arenarius, E. horridus, E. latifrons, E. lehmannii, E. longifolius, and E. trispinosus. The genetic distances between both groups were 0.12-0.47% for ITS and 0.08-0.16% for rbcL DNA. The results indicate recent (probably pleistocenic) speciation for this group of cycads, and the relationships are discussed with reference to affinities based on morphology and distribution.

Epicuticular waxes and glaucousness of Encephalartos leaves

The epicuticular leaf waxes from four glaucous and four non-glaucous species of Encephalartos were examined by GC-mass spectrometry and SEM techniques. The four glaucous-leaved species, E. horridus, E. lehmannii, E. princeps and E. trispinosus, all occurring in xeric conditions in the Eastern Cape Province of South Africa, were conspicuous in having leaf waxes containing a series of secondary alcohols. In addition to 10-nonacosanol as the principal wax component, minor amounts of C 25C 31 10-alkanols, 4,10-, 5,10- and 7,10-nonacosanediol and the ketone, 10-nonacosanone, were detected in these species. The adaxial leaflet surfaces of the glaucous species all showed a distinctive trabecular deposit of wax platelets when viewed microscopically. By contrast, secondary alcohols and ketones were absent in waxes from the non-glaucous species, and the surface of leaflets of these taxa were relatively featureless microscopically. Varying quantities of alkanes, fatty acids, primary alcohols, aldehydes and alkyl esters were present in all samples. Amongst the non-glaucous species, E. altensteinii, E. natalensis and E. woodii were similar in their wax composition, but differed from E. villosus. Alkanes were dominant in the latter species, which had high proportions of hentriacontane and tritriacontane in parallel with the most prominent oxygenated wax compounds, C 32 and C 34 fatty acids and aldehydes.

Encephalartos successibus (Zamiaceae): a new species from Uganda

Encephalartos successibus , a new species from Uganda, is described, illustrated and circumscribed in terms of other tropical African arborescent species of Encephalartos , It is a large arborescent plant, with mostly non-overlapping leaflets, The strobili are green and glabrous; the megastrobilus is ovoid, shortly pedunculate but with peduncle buried in cataphylls so that the megastrobilus appears to be sessile, with the exposed faces of the megasporophylls more or less smooth; the microstrobili emerge in succession, being narrowly ovoid, long-pedunculate, with the exposed faces of the microsporophylls smooth.

In Vitro Regeneration of Stangeria eriopus

Abstract In South Africa, the indigenous cycads comprise 28 species of Encephalartos (Za-miaceae) and Stangeria eriopus (Kunze) Baillard (3), the latter species being the sole representative of the Stangeriaceae. Present cycad populations are under severe pressure from combined effects of agricultural and urban development, exploitation by the tribal “medicine-men”, activities of plant collectors, and demands from scientific and educational institutions. In addition, the relatively slow growth rate, limited potential for vegetative propagation, and the restricted supply of viable seed further exacerbate the delicate conservation status of these dioecious plants (2).

The occurrence of coralloid roots on the South African species of the Cycadales and their ability to fix nitrogen symbiotically

Thirty-three species of Encephalartos, which include all the known species indigenous to the Republic of South Africa, together with Stangeria eriopus, were found to form coralloid roots. In all cases, specimens were found in which the coralloid roots were infected with Cyanobacteria (blue-green algae) and these roots in all cases reduced acetylene to ethylene, and fixed nitrogen. Daar is vasgestel dat al 33 die Encephalartos-spesies wat ondersoek is, sowel as Stangeria eriopus koraalvormige wortels vorm. Die ondersoekte spesies het al die beskrewe spesies wat inheems aan die Republiek van Suid-Afrika is ingesluit. In alle gevalle is eksemplare gevind waarvan die koraalvormige wortels met Cyanobacteria (blougroen alge) geïnfekteer was. Sulke wortels het in alle gevalle oor die vermoë beskik om asetileen tot etileen te reduseer en om stikstof te bind.

Heterochromatin in <i>Encephalartos</i>

Fluorescence analysis of the karyotypes of two species of Encephalartos has revealed the presence of considerable amounts of heterochromatin. The heterochromatin is present mainly on two of the chromosome pairs, in one of which it is associated with the nucleolar organising regions. The significance of the heterochromatin is discussed relative to the highly specialised nature of cycad species.

A New Species of Encephalartos from Swaziland

Encephalartos heenanii R. A. Dyer is described for the first time. It is indigenous in Swaziland and is nearest related to E. paucidentatus Stapf Burtt Davy.

Zonal Structure of the Shoot Apex in Encephalartos, Bowenia, and Macrozamia

1. The structure of the shoot apex is described for six species of Encephalartos and for one species each of Bowenia and Macrozamia. 2. The shoot apex consists of four zones. The summit is occupied by a zone of initiation from which growth converges to a zone of central mother cells where increase in volume predominates. Growth is divergent from the central mother cell zone. 3. A peripheral zone, which is derived from the central mother cells and superficial layer, flanks the central mother cell zone. Leaf primordia, cortex, and vascular tissue are derived from this zone. 4. The zone of central mother cells is underlaid by a rib meristem which builds up the massive pith.

Leaflets of Cycadaceae

1. A key based on topographical characters of leaflets is workable for genera. 2. The leaflets of the different species vary in color from bright green to dark green or dull gray-green; the shape and texture of the leaflets show an equal amount of variation. 3. A thick-walled, cutinized epidermis is characteristic of all the species examined; and a hypodermis is differentiated to some extent in all the species studied except Bowenia. 4. A well differentiated upper palisade is present in Cycas, Dioon, Encephalartos, Ceratozamia, Macrozamia, and Zamia furfuracea. Other species of Zamia show a more or less palisade region, but the cells are scarcely elongated or regular enough to constitute a true palisade. 5. The spongy mesophyll in most of the species examined is composed of transversely elongated cells. In nine of the species the cells are yoke-shaped. 6. In all of the species studied, thick-walled cells are found around the vascular bundles or scattered through the mesophyll. 7. Mucilage canals are present in Macrozamia, Dioon, Stangeria, and some species of Encephalartos. 8. In all of the species considered, except Bowenia serrulata, crystals of calcium oxalate are found. 9. Stomata were found on the upper as well as on the lower surfaces of the leaflets of Macrozamia Moorei and Bowenia serrulata. In the other species examined they were found on the lower surface only. 10. In studying the character of the leaflets two factors, heredity and environment, must be taken into consideration. The favorable environmental factors in greenhouse cultivation have perhaps modified the xerophytic structure of the leaflets studied.

XIV. The Comparative Anatomy of certain Species of Encephalartos, Lehm.

XIV. The Comparative Anatomy of certain Species of Encephalartos, Lehm Get access W. C. Worsdell, F.L.S. W. C. Worsdell, F.L.S. Search for other works by this author on: Oxford Academic Google Scholar Transactions of the Linnean Society of London. 2nd Series. Botany, Volume 5, Issue 14, October 1900, Pages 445–459, https://doi.org/10.1111/j.1095-8339.1900.tb00201.x Published: 09 April 2009