145 research outputs found
Recircumscription and distribution of elements of the ‘Ceterach cordatum’ complex (Asplenium: Aspleniaceae) in southern Africa
Ceterachoid aspleniums in southern Africa have long been treated as a single widespread and variable taxon, Asplenium
cordatum (Thunb.) Sw. (= Ceterach cordatum Thunb.). In addition to A. cordatum, a further two ceterachoid taxa are now recognized
as occurring in the Flora of southern Africa (FSA) region, namely A. capense (Kunze) Bir, Fraser-Jenk. & Lovis and
A. phillipsianum (Kümmerle) Bir, Fraser-Jenk. & Lovis. We provide full descriptions and distributions of these three taxa.http://www.sanbi.org/products/publications/bothalia.ht
Triandra pellabergensis (Hyacinthaceae subfam. Urgineoideae), a new genus and species from Pella se Berge, Northern Cape Province, South Africa
Within the framework of a taxonomic revision of subfamily Urgineoideae based on morphological, genetic and phytogeographic data covering numerous samples from its whole range of distribution, we here describe a new genus and species from Pella se Berge in northwestern South Africa. Triandra gen. nov. is easily characterized by the absence of stamens associated with the outer tepal whorl, therefore having only three stamens per flower, a character previously unknown in Hyacinthaceae. Triandra pellabergensis sp. nov. produces hypogeal bulbs with filiform proteranthous leaves, spurred bracts, lax racemes with few, nodding, nocturnal flowers and erect capsules with the withered tepals persisting atop. The new species resembles Urginea revoluta in general morphology, although this latter species has six stamens per flower, a different seed morphology, a distinct phytogeographic pattern, and a distant phylogenetic relationship. A complete morphological description is presented for the new genus and species, including data on its biology, ecology and distribution.This work was partly supported by H2020 Research and Innovation Staff Exchange Programme of the European Commission, project 645636: ‘Insect-plant relationships: insights into biodiversity and new applications’ (FlyHigh), and the grants ACIE18–03 UAUSTI18–02 and UAUSTI19-08 from the University of Alicante
Vera-duthiea zebrina (Asparagaceae, Scilloideae), a new species from eastern South Africa, and a first genus record for southern Africa
In the course of revising the subfamily Urgineoideae of the Hyacinthaceae it became evident, based on molecular and morphological data, that some plants usually named ‘Drimia indica’ from northeastern South Africa represent rather an undescribed species of Vera-duthiea. This is the first record of this genus occurring in southern Africa. The new species (V. zebrina) was collected and illustrated some 50 years ago, but never validly published. We here provide data on its morphology, ecology, and distribution.This work was partly supported by H2020 Research and Innovation Staff Exchange Programme of the European Commission, project 645636: ‘Insect-plant relationships: insights into biodiversity and new applications’ (FlyHigh)
ISOFLAVONES FROM CALPURNIA AUREA SUBSP. AUREA AND THEIR ANTICANCER ACTIVITY
Background: Calpurnia aurea is an African medicinal plant used in many countries in Africa to treat a range of medical conditions or disorders. Extracts of the plant were shown to be active in antibacterial and antioxidant assays as well as against lice, ticks and maggots. The aim of the study was to isolate the phytochemical constituents from the plant and to test them in appropriate bioassays dependent on the compounds isolated in order to provide a rationale for the use of the plant in ethno-medicine or to provide some information on its constituents.
Materials and methods: The stem and bark of the plant was extracted with organic solvents of varying polarity and the extracts separated and purified using column chromatography. The isolated compounds were identified by NMR spectroscopy and the compounds were tested for their in vitro anticancer activity against breast (MCF7), renal (TK10) and melanoma (UACC62) human cell lines using an in house method developed at the CSIR, South Africa.
Results: The isoflavones, 4′,5,7-trihydroxyisoflavone (1), 7,3′-dihydroxy-5′-methoxyisoflavone (2), 7-hydroxy-4′,8-dimethoxyisoflavone (3), 7-acetoxy-4′,8-dimethoxyisoflavone (4) and 3',7-dihydroxy-4′,8-dimethoxyisoflavone (5), a pterocarpan (3-acetoxy-9-methoxypterocarpan) and a quinolizidine alkaloid (calpurnine) were isolated from the stem and bark of Calpurnia aurea. The tetrasubstituted isoflavone 5 was found to be the most active in the three cell lines amongst all the compounds tested. This was followed by trisubstituted isoflavone 2.
Conclusion: The isoflavones showed moderate activity against the renal, melanoma and breast cancer cell lines tested against, with the isoflavones 2 and 5 showing the best activity of the compounds tested. These isoflavones may have a synergistic effect with other anticancer drugs
Asphodelaceae : Alooideae. Gasteria croucheri subsp.Pondoensis, a new cremnophyte from Pondoland, South Africa
We describe a new subspecies of Gasteria croucheri
(Hook.f.) Baker from northern Pondoland, Eastern
Cape, an obligate cremnophyte belonging to Gasteria
Duval sect. Longifl orae Haw. ser. Longifoliae Haw. The
members of this series are all characterized by narrow,
elliptical, comparatively dull-coloured fl owers in which
the swelling in the upper half approximates the rather
unpronounced basal gasteriform portion (Van Jaarsveld
et al. 1994). Mature specimens of the new taxon produce
both leaves (up to 1.5 m long) and fl owers (up to 50 mm
long) that are exceptionally long in the genus. To date,
plants have only been found in the Msikaba and Mtentu
River systems adjacent to Mkambati Game Reserve
(Figure 8), the topography of which is characterized by
rugged plateaux of 100–500 m, dissected deeply by narrow
river gorges. This distribution falls within the Pondoland
Centre of Plant Endemism (Van Wyk & Smith
2001). Specimens grow on cliffs both fully exposed on
southern aspects, as well as within the shaded margins of
riverine forest. It is a clump-forming species with long,
angular and often sickle-shaped leaves, most of which
are pendulous in mature specimens (Figure 9).http://www.sanbi.or
Kalanchoe winteri Gideon F.Sm., N.R.Crouch & Mich.Walters (Crassulaceae), a new species from the Wolkberg Centre of Endemism, South Africa
A new Kalanchoe species, K. winteri
Gideon F.Sm., N.R.Crouch & Mich.Walters, is described
from rocky grasslands of the Wolkberg region
of Limpopo province, South Africa. The
species is closely allied to both K. thyrsiflora
Harv. and K. luciae Raym.-Hamet, from which it
is readily separable on vegetative and reproductive
characteristics.Eine neue Kalanchoe-Art, K.
winteri Gideon F. Sm., N. R. Crouch & Mich.Walters,
wird aus felsigen Grasländern der Wolkberg-
Region in der Provinz Limpopo, Südafrika,
beschrieben. Die Art ist nah mit K. thyrsiflora
Harv. und K. luciae Raym.-Hamet verwandt, von
denen sie leicht durch vegetative und generative
Merkmale unterschieden werden kann.http://www.bcss.org.uk/brad.phpam2017Centre for Wildlife Managemen
The African plants initiative (API) in South Africa
Given the ongoing and often destructive impact of humans on
the natural environment, the need for sound and robust taxonomies
has become critically important (see for example Godfray & Knapp,
2004). The difficulty with naming organisms is especially acute in
African countries, where resources and facilities for taxonomic research
are limited (Klopper & al., 2002), and biodiversity is usually
relatively high. South Africa, for example, incorporates the world’s
richest temperate flora with 19,581 indigenous plant species from
2267 genera and 349 families of vascular plants (Germishuizen &
al., 2006; Steenkamp & Smith, 2006). Approximately 65% of the
country’s vascular plant species are endemic (Raimondo & al.,
2009), with many occurring in its three regions and 15 centres of
plant endemism (Van Wyk & Smith, 2001).
Expertise as well as preserved and living material of the biodiversity
of developing nations—typically former colonies of imperialist
nations—are often located in developed countries and
not available in the country of origin (Figueiredo & Smith, 2010).
The CBD recognises this impediment and in Article 17 calls on
signatory parties to exchange and repatriate information to facilitate
research (Global Taxonomy Initiative, 2001). To overcome the
obstacle of having to physically ship valuable—and essentially
irreplaceable—pressed plant specimens between herbaria around
the world, the African Plants Initiative (API) was conceived. The
notion was to scan type specimens and make electronic images of
them available online. This approach efficiently enables both virtual
repatriation of information, and access by researchers of other
herbaria to the most important accessioned material, thus removing
some of the constraints to taxonomic work. It has been six years
since the inception of the API, and this paper reports on its achievements
in South Africa, one of the founding countries of the thrust
A revised generic classification for <em>Aloe</em> (Xanthorrhoeaceae subfam. Asphodeloideae)
Grace, Olwen M., Klopper, Ronell R., Smith, Gideon F., Crouch, Neil R., Figueiredo, Estrela, Rønsted, Nina, Van Wyk, Abraham E. (2013): A revised generic classification for Aloe (Xanthorrhoeaceae subfam. Asphodeloideae). Phytotaxa 76 (1): 7-14, DOI: 10.11646/phytotaxa.76.1.2, URL: http://dx.doi.org/10.11646/phytotaxa.76.1.
Aloe arborescens Mill. ‘Estelle Potgieter’ (Asphodelaceae subfam. Alooideae), a new cultivar in a variable species, with notes on aloes at the South African National Biodiversity Institute, Pretoria
Aloe arborescens Mill. ‘Estelle Potgieter’
(Asphodelaceae subfam. Alooideae), a new
cultivar, is established in this variable species.
Aloes at the South African National Biodiversity
Institute, Pretoria, South Africa, are discussed.Aloe arborescens Mill. ‘Estelle
Potgieter’ (Asphodelaceae subfam. Alooideae) wird
als neue Sorte dieser variablen Art beschrieben.
Die Aloen am South African National Biodiversity
Institute, Pretoria, Südafrika, werden diskutiert.http://www.bcss.org.uk/brad.phpam2022Plant Production and Soil Scienc
Reinstatement of Aloe candelabrum A.Berger (Asphodelaceae: Alooideae), a tree-like aloe of KwaZulu-Natal province, South Africa
Aloe candelabrum A.Berger (Asphodelaceae:
Alooideae), a stately, single-stemmed
species from the KwaZulu-Natal province in eastern
South Africa, which had been included in the
synonymy of A. ferox Mill. for some years, is reinstated.
The entire distribution range of A. candelabrum
falls within the Maputoland-Pondoland
Region of Endemism on the eastern seaboard of
South Africa. In contrast, Aloe ferox occurs widely
in the Western and Eastern Cape provinces of
South Africa, the southern Free State province, as
well as southern Lesotho. It does not occur in
KwaZulu-Natal.Aloe candelabrum A. Berger
(Asphodelaceae: Alooideae), eine stattliche, einstämmige
Art aus der Provinz KwaZulu-Natal im
östlichen Südafrika, die jahrelang in die Synonymie
von A. ferox Mill. gestellt wurde, wird
wieder anerkannt. Das gesamte Verbreitungsgebiet
von A. candelabrum liegt innerhalb der Endemismus-
Region Maputoland-Pondoland an der
östlichen Meeresküste von Südafrika. Im Gegensatz
dazu ist Aloe ferox weit verbreitet in den
südafrikanischen Provinzen Western Cape und
Eastern Cape, der südlichen Provinz Free State
sowie im südlichen Lesotho; in KwaZulu-Natal
kommt sie nicht vor.http://www.bcss.org.uk/brad.phpam2017Plant Scienc
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