Phytogeography of Pelargonium

Bothalia ◽  
1983 ◽  
Vol 14 (3/4) ◽  
pp. 517-523 ◽  
Author(s):  
J. J. A. Van der Walt ◽  
P. J. Vorster
Keyword(s):  
Southern Africa ◽  
Summer Rainfall ◽  
Western Cape ◽  
The South ◽  
Winter Rainfall ◽  
Distribution Maps ◽  
Present Distribution ◽  
The Individual ◽  
Rainfall Region

The vast majority of the approximately 2(H) species of Pelargonium oeeurs in Africa. About SO per cent of the species are endemic to the winter rainfall region of the Cape Province, and the centre of distribution lies in the south-western Cape. The distribution of the individual sections are discussed with the aid of distribution maps. The centre of distribution of most sections is in the south-western Cape, hut a few sections are centred in the eastern and western Cape. Several sections are represented by a few species in the summer rainfall region of southern Africa. As no fossils of Pelargonium are known, deductions about the origin of the genus can only be based on the present distribution of species, according to which arguments in favour of both a northern and a southern origin can he supported.

scholarly journals The distribution of the dwarf succulent genus Conophytum N.E.Br. (Aizoaceae) in southern Africa

Bothalia ◽  
2016 ◽  
Vol 46 (1) ◽  
Author(s):  
Andrew J. Young ◽  
Philip G. Desmet
Keyword(s):  
Climate Change ◽  
South Africa ◽  
Southern Africa ◽  
Conservation Planning ◽  
Cape Floristic Region ◽  
Geographical Range ◽  
Western Cape ◽  
Succulent Karoo ◽  
Winter Rainfall ◽  
Rainfall Region

Background: The dwarf succulent genus Conophytum N.E.Br. is one of the most species rich in the Aizoceae. The genus is most closely associated with a region of high floral endemism and biodiversity, the Succulent Karoo biome in south-western Africa.Objectives: To examine the distribution of Conophytum in south-western Namibia and in the Northern and Western Cape Provinces of South Africa.Method: A database comprising 2798 locality records representing all known species and subspecies of the genus Conophytum has been constructed.Results: The genus is primarily restricted to the arid winter-rainfall region of the Northern and Western Cape Provinces of South Africa and south-western Namibia, within the Greater Cape Floristic Region. Whilst taxa are found across all the main biomes in the region (the Succulent Karoo, Nama Karoo, Desert and Fynbos biomes), 94% of Conophytum taxa are found only in the Succulent Karoo biome and predominantly (88% of taxa) within South Africa. Endemism within specific bioregions is a feature of the genus and ~60% of taxa are endemic to the Succulent Karoo. Approximately 28% of all taxa could be considered point endemics. Whilst the genus has a relatively wide geographical range, we identify a pronounced centre of endemism in the southern Richtersveld.Conclusion: The genus Conophytum can be used as a good botanical model for studying patterns of diversity and speciation in the Succulent Karoo biome, the effects of climate change on dwarf succulents, and for informing conservation planning efforts.

Large Summer Rainfall Events and Their Importance in Mitigating Droughts over the South Western Cape, South Africa

2021 ◽  
Vol 22 (3) ◽  
pp. 587-599
Author(s):  
W. M. De Kock ◽  
R. C. Blamey ◽  
C. J. C. Reason
Keyword(s):  
Urban Areas ◽  
Cape Town ◽  
Summer Rainfall ◽  
Western Cape ◽  
The South ◽  
African Region ◽  
Rainfall Events ◽  
Atmospheric Rivers ◽  
Piped Water ◽  
Almost All

AbstractAlthough the south Western Cape receives most of its rainfall between May and September, there are substantial rainfall events in some summers. These events are of interest in themselves as well as for their possible role in mitigating the frequent winter droughts that the region suffers from. Most recently, greater Cape Town suffered a devastating drought during 2015–18 known as the Day Zero drought due to the high risk of urban areas running out of piped water supply. Estimated data from the city show that major dam levels in the south Western Cape increased more than 1% in some cases after large rainfall events (LREs) in the summer of 2018/19. This increase is significant as dam levels often decrease by several percent per month during the hot summer. In this study, LREs over the south Western Cape during the summer (October–March) are investigated together with dam level data. Most summer LREs result from atmospheric rivers (ARs) or cutoff lows (COLs). ARs have not been previously studied in the South African region except for one study for winter that showed they are responsible for almost all the heavy rainfall events in the Western Cape. Although COLs are most common in the transition months, they can also occur in midwinter and summer. COLs tend to last longer and cover larger areas than ARs, which typically yield relatively short bursts of intense rainfall mostly concentrated around greater Cape Town. After each summer LRE, average dam levels increase by up to 5%, suggesting they are very important for drought recovery. In particular, summer LREs following the anomalously dry winters of 1980, 1984, 2003, 2004, and 2015–18 played an important role in mitigating those droughts.

Eight new species of Moraea (Iridaceae) from southern Africa with range extensions and morphological notes in the genus

Bothalia ◽  
2013 ◽  
Vol 43 (2) ◽  
pp. 153-166 ◽  
Author(s):  
P. Goldblatt ◽  
J. C. Manning
Keyword(s):  
New Species ◽  
Southern Africa ◽  
Western Cape ◽  
Winter Rainfall ◽  
African Species ◽  
Basal Leaf ◽  
Pale Yellow ◽  
Northern Cape ◽  
Sub Saharan ◽  
African Genus

We describe eight new southern African species in the largely sub-Saharan African genus Moraea L., one from the winterdry Great Karoo and the others from the winter-rainfall zone of the southwest of the subcontinent. M. striata Goldblatt J.C.Manning (subg. Visciramosae Goldblatt) from the southern foothills of the Great Swartberg Mtns has khaki-green flowers with reflexed tepal limbs streaked with dark lines. The acaulescent M. singularis Goldblatt J.C.Manning (subg. Umbellatae Goldblatt J.C.Manning) with terete leaf blades is restricted to the dry, interior foothills of the Kamiesberg in Northern Cape. M. filamentosa Goldblatt J.C.Manning, subg. Acaules (Baker) Goldblatt J.C.Manning, is described from the dry interior of Namaqualand in Northern Cape. The species is closely allied to the widespread M. falcifolia Klatt. In subg. Polyanthes (Goldblatt) Goldblatt J.C.Manning, we describe M. thermarum Goldblatt J.C.Manning (sect. Hexaglottis (Vent.) Goldblatt) from southwestern Namibia, allied to M. brevituba (Goldblatt) Goldblatt, and M. lazulina Goldblatt J.C.Manning (sect. Pseudospicata Goldblatt J.C.Manning) from the Little Karoo, until now confused with M. exiliflora Goldblatt but differing in its larger flowers with strongly reflexed tepals. The new M. petricola Goldblatt J.C.Manning (subg. Vieusseuxia (D.Delaroche) Goldblatt), is restricted to higher elevations of the Pakhuis Mtns of northern Western Cape. Lastly, in subg. Homeria (Vent.) Goldblatt J.C.Manning, we recognize M. doleritica Goldblatt J.C.Manning with pale yellow flowers and anthers exceeding the style branches, restricted to dolerite outcrops in the Great Karoo, and M. eburnea Goldblatt J.C.Manning from the northern foothills of the Klein Swartberg, which has a single, basal leaf and pale yellow flowers with filaments free distally. Moraea now has 222 species, including 203 in southern Africa, of which 200 are endemic to the region. In addition to describing new species, the paper brings to light range extensions of a further eight species: M. barnardii L.Bolus, M. elliotii Baker, M. exiliflora Goldblatt, M. falcifolia Goldblatt J.C.Manning, M. fenestralis (Goldblatt E.G.H.Oliver) Goldblatt, M. louisabolusiae Goldblatt, M. tulbaghensis L.Bolus and M. unguiculata Ker Gawl. Each of the species falls into one of the subgenera mentioned for the new species except M. fenestralis which belongs in subg. Galaxia.

New species and subspecies of Babiana, Hesperantha, and Ixia (Iridaceae: Crocoideae) from southern Africa; range extensions and morphological and nomenclatural notes on Babiana and Geissorhiza

Bothalia ◽  
2012 ◽  
Vol 42 (2) ◽  
pp. 137-145 ◽  
Author(s):  
P. Goldblatt ◽  
J. C. Manning
Keyword(s):  
New Species ◽  
Southern Africa ◽  
New Record ◽  
First Record ◽  
Winter Rainfall ◽  
Late Flowering ◽  
Typical Form ◽  
Northern Cape ◽  
Rainfall Region

Babiana rivulicola from stream banks in the Kamiesberg in Namaqualand and terete-leaved Ixia teretifolia from the Roggeveld, both in Northern Cape, are new species of these two largely winter-rainfall region genera. Late-flowering populations of Hesperantha radiata with crowded spikes of smaller flowers are segregated from the typical form as subsp. caricina. We also document the first record of B. gariepensis from Namibia, correct the authority for B. purpurea Ker Gawl., discuss morphologically aberrant populations of B. tubiflora from Saldanha, provide an expanded description for B. lapeirousiodes based on the second and only precisely localized collection of this rare Namaqualand species, and expand the circumscription of Geissorhiza demissa to accommodate a new record from the Kamiesberg, including revised couplets to the existing key to the species.

Patterns of geophyte diversity and storage organ size in the winter-rainfall region of southern Africa

2005 ◽  
Vol 11 (1) ◽  
pp. 101-109 ◽  
Author(s):  
Şerban Procheş ◽  
Richard M. Cowling ◽  
Derek R. du Preez
Keyword(s):  
Southern Africa ◽  
Organ Size ◽  
Storage Organ ◽  
Winter Rainfall ◽  
And Storage ◽  
Rainfall Region

scholarly journals Taxonomy of the genus Ehrharta (Poaceae) in southern Africa: the Setacea group

Bothalia ◽  
1987 ◽  
Vol 17 (1) ◽  
pp. 67-73 ◽  
Author(s):  
G. E. Gibbs Russell
Keyword(s):  
Southern Africa ◽  
Leaf Blade ◽  
Plant Size ◽  
Species Group ◽  
Western Cape ◽  
The South ◽  
Western Cape Province ◽  
Blade Width ◽  
Sterile Lemma

The Setacea species group in the genus Ehrharta Thunb. is differentiated morphologically by the short first sterile lemma and by inflorescences of fewer than 20 spikelets. The Setacea group is composed of two species, each with subspecies linked by intraspecific intermediates: E. rupestris Nees ex Trin. subsp.  rupestris; subsp.  tricostata (Stapf) Gibbs Russell; subsp.  dodii (Stapf) Gibbs Russell and E. setacea Nees subsp.  setacea; subsp.  scabra (Stapf) Gibbs Russell; subsp. uniflora (Burch, ex Stapf) Gibbs Russell; subsp.  disticha Gibbs Russell. All taxa are endemic to the Fynbos vegetation of the south-western Cape Province, with distribution centred in the Caledon degree grid (3419). Parallel trends for plant size and habit, leaf blade width and position, and spikelet size are demonstrated in both species, with similar plant types occurring in similar geographical areas.

A Taxonomic Revision of the Othonna bulbosa Group (Asteraceae: Senecioneae: Othonninae)

2019 ◽  
Vol 104 (4) ◽  
pp. 515-562 ◽  
Author(s):  
Simon L. Magoswana ◽  
James S. Boatwright ◽  
Anthony R. Magee ◽  
John C. Manning
Keyword(s):  
South Africa ◽  
South African ◽  
Geographical Distribution ◽  
Taxonomic Revision ◽  
Cape Floristic Region ◽  
The South ◽  
Winter Rainfall ◽  
African Species ◽  
Taxonomic Treatment ◽  
Rainfall Region

Othonna L. (Asteraceae: Senecioneae: Othonninae) is a genus of some 120 species concentrated in the Greater Cape Floristic Region (GCFR) of South Africa, with a few species extending into southern Namibia, Angola, and Zimbabwe. The South African species of Othonna were last revised more than a century ago, and many species, particularly from the southern African winter rainfall region, remain poorly understood. This study focused on the geophytic species comprising the O. bulbosa group, distinguished by their tuberous rootstock and annual, leafy, aerial stems. A comprehensive taxonomic treatment is presented, including descriptions, complete nomenclature and typification, illustrations, and geographical distribution. Twenty-five species are recognized, of which four are newly described (O. lilacina Magoswana & J. C. Manning, O. nigromontana Magoswana & J. C. Manning, O. revoluta Magoswana & J. C. Manning, and O. sinuata Magoswana & J. C. Manning), and 18 names are reduced to synonymy. The species differ in habit, shape and incision of foliage, capitulum type (radiate vs. disciform), number of involucral bracts, pappus length, and cypselae (myxogenic vs. nonmyxogenic). We place the species into four morphologically diagnosable series (series Heterophyllae Magoswana & J. C. Manning, series Disciformes Magoswana & J. C. Manning, series Perfoliatae Magoswana & J. C. Manning, and series Undulosae Magoswana & J. C. Manning) based on habit and capitulum type.

Tendencies in the geographical distribution of the genus Mariscus (Cyperaceae) in southern Africa*

Bothalia ◽  
1983 ◽  
Vol 14 (3/4) ◽  
Author(s):  
P. J. Voster
Keyword(s):  
Geographical Distribution ◽  
Southern Africa ◽  
Environmental Conditions ◽  
West Coast ◽  
Summer Rainfall ◽  
Annual Rainfall ◽  
The West ◽  
Water Requirements ◽  
Winter Rainfall ◽  
Flora Of Southern Africa

The genus Mariscus occurs over practically the whole of the Flora of Southern Africa (FSA) region, with the exception of the west coast and the Karoo region of the Cape Province. Practically no species occur under conditions of less than 250 mm of rain per annum, whereas the highest concentrations of subgenera/sections and species occur where the annual rainfall is more than 500 mm. All the species in the region are summer rainfall plants, or if they occur in the winter rainfall area they behave like summer rainfall plants. The different subgenera/sections recognized within the genus differ widely in respect of their water requirements, yet there is a general concentration of taxa in the eastern part of the country where the rainfall is higher than in the west. Nevertheless, the highest concentrations of taxa are not in the areas of highest rainfall, which suggests that topographical diversity is probably the most important factor determining concentrations of taxa. The geographical distribution of each subgenus/section in the FSA region is explained in relation to the total distribution of the subgenus/section. The possible climatic or environmental conditions which may determine the distribution of each subgenus/section are mentioned, and the concentration of species within each subgenus/section is demonstrated by means of maps.

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