Southern Namaqualand Research Articles

1023 HAEMANTHUS HUMANII: Amaryllidaceae

SummaryThe new species, Haemanthus humanii G.D.Duncan, is described. This extraordinary, winter‐growing, summer‐flowering dwarf geophyte is endemic to flats and undulating plains in the southern Namaqualand region of the Western Cape, South Africa. Details of its history, taxonomy, habitat and cultivation are given.

New species of Hessea and Strumaria (Amaryllidaceae: Amaryllideae) from Namaqualand in Northern Cape and Western Cape, South Africa

Described are two new species in the southern African subtribe Strumariinae (Amaryllidaceae: Amaryllideae). In Hessea the new species H. pallida (subg. Hessea) from Toringberg, Western Cape, on the westernmost edge of the southern Namaqualand Hardeveld, is known on the edges of a seasonal pan within Namaqualand Granite Renosterveld. The whitish to pale pink flowers have crisped tepal edges in common with three species known exclusively from fire-prone fynbos in the Core Cape Floristic Region. Hessea pallida is inferred to be most closely related to H. monticola. The two species differ in the size, colouring and markings of the flowers, shape of the tepals and flowering habit. Hessea monticola is a fire obligate whereas H. pallida flowers regularly in a habitat free of fire. The recognition of Toringberg as a minor refugium for core Cape plants is briefly discussed. In Strumaria the new species S. crystallina (subg. Strumaria) is described from the Nama shales of the Skaaprivier gorge on the northern Namaqualand Escarpment. The widely campanulate flowers have sculptured stamens and style like those of S. bidentata, but S. crystallina stands out in having soft, narrow leaves unlike the firm, upright leaves spread into a flattened fan as in most other species in the subgenus, apart from S. prolifera in northern Namaqualand. Both new species are known only from the type locality.

Tylecodon celatus, a new cryptic succulent from Nuwerus, Namaqualand (Western Cape, South Africa)

Tylecodon celatus is named from plants found near Nuwerus, southern Namaqualand in the Western Cape. It is a cryptic semiscandent dwarf summer deciduous succulent with yellowish green to greenish flowers only known from the Farm Erdvarkgat growing on sandstone of the Flaminkberg Formation (Vanrhynsdorp Group). It is related to T. suffultus and T. similis from the same region.

Cheiridopsis alba-oculata (Aizoaceae: Ruschioideae, Ruschieae) — A new quartz-endemic from southern Namaqualand, South Africa

Cheiridopsis alba-oculata Klak & N.A. Helme is a new species known from two populations in the Garies region of southern Namaqualand, where it appears to be restricted to patches of quartz-gravel. The species belongs to the Cheiridopsis–Odontophorus alliance because of its papillate leaves and the 9- or 10-locular fruits with large closing bodies. The isophylly and globose fruits with raised tops suggest that it is closely related to C. subg. Odontophoroides and Odontophorus. C. alba-oculata is geographically isolated in this group, whose other members are restricted to northern Namaqualand. C. alba-oculata resembles Cheiridopsis ponderosa and Cheiridopsis pilosula in its densely papillate leaves but is distinguished from them by its strongly keeled, apically toothed leaves.

The late pre-colonial site of Komkans 2 (KK002) and an evaluation of the evidence for indigenous copper smelting in Namaqualand, southern Africa

Excavations at the late Holocene archaeological site KK002 are described. This small rock shelter, 17 km from the coast in southern Namaqualand, South Africa, contained a shallow deposit with a rich assemblage. Limited evidence of mid-Holocene occupation occurs, but the majority of occupation took place within the last 2000 years and can be split into two primary layers. The finds included stone artefacts with many clear quartz backed tools, whole, broken and partly made ostrich eggshell beads, pottery, worked wood and reeds, wood shavings, metal artefacts of indigenous and European origin, glass trade beads and a variety of subsistence remains, including those of marine animals. All three copper-containing artefacts are of European origin. With so much having been said about the possibility of an indigenous source of copper in Namaqualand, further investigation of this suggests that copper was not mined locally, but that lumps of native copper were collected at times. There is also no evidence of copper-smelting south of the Orange River, although this was practised in central Namibia.

Taxonomy of the Moraea saxicola complex (Iridaceae: Iridoideae) of arid, western southern Africa, with the new species, M. acocksii, M. geminifolia, M. quartzicola and M. teretifolia

Included in Moraea subg. Polyanthes sect. Deserticola Goldblatt, species of the M. saxicola complex have one or two basal foliage leaves, a typical Moraea-type flower with well-developed style branches and crests, nectar guides present only on the limbs of the larger outer tepals, and an ovary included in the inflorescence spathes. The complex extends from southwestern Namibia in the north to the slopes of the Gifberg near Klawer in Western Cape, South Africa, in the south. Examination of plants in the field and herbarium specimens collected since the group was last studied taxonomically shows that the complex includes four undescribed species: 1. terete-leaved Moraea acocksii Goldblatt & J.C.Manning; 2. two-leaved M. geminifolia Goldblatt & J.C.Manning; 3. terete-leaved M. teretifolia Goldblatt & J.C.Manning [all from northern Namaqualand in Northern Cape]; and 4. diminutive M. quartzicola Goldblatt & J.C.Manning from the southern Knersvlakte of Western Cape. The circumscriptions of Moraea bolusii Baker and M. namibensis Goldblatt are adjusted in light of new information and the range of the latter is expanded to include the Richtersveld of South Africa. We also expand the circumscription of M. saxicola, previously a Namibian endemic, to include plants from southern Namaqualand and the Richtersveld. The complex now includes eight species, and we provide a complete revision of all species, with distribution maps and illustrations of three of the new species.

PETROGENESIS OF CU-NI SULPHIDE ORES FROM O'OKIEP AND KLIPRAND, NAMAQUALAND, SOUTH AFRICA: CONSTRAINTS FROM CHALCOPHILE METAL CONTENTS

The petrogenesis of sulphide ores in the O’okiep district has remained controversial. Based mainly on the concentration of chalcophile metals (PGE, Cu, Ni), it is proposed that the sulphides segregated from a basaltic magma generated during melting of sub-continental lithospheric mantle. Sulphide saturation of the magma was delayed due to relatively high fO2 until crustal contamination occurred during the advanced stages of differentiation. The immiscible sulphide melt was entrained and fractionated in dynamic magma conduits. Sulphides enriched in monosulphide solid solution (mss) component precipitated at depth in the Kliprand area of southern Namaqualand to form the Hondekloof deposits, whereas the O’okiep ores crystallised at shallower levels from highly fractionated residual sulphide liquids enriched in intermediate solid solution (iss). Sulphides of intermediate composition occur at Ezelsfontein. In the context of this model, the O’okiep intrusions could represent the proximal magmatic members of an IOCG suite of deposits, raising the prospect for additional IOCG deposits elsewhere in southern Africa. The model also predicts an enhanced potential at O’okiep for undiscovered Ni sulphide ores at depth.

<i>Romulea pilosa</i> and <i>R. quartzicola</i> (Iridaceae: Crocoideae), two new species from the southern African winter rainfall region, with nomenclatural corrections

Romulea pilosa J.C.Manning Goldblatt and R. quartzicola J.C.Manning Goldblatt are two narrow endemics from the southern African winter rainfall region. An early, fragmentary collection of R. pilosa from Riviersonderend lacked the diagnostic corm and was thus mistakenly associated with R. tetragona (sect. Ciliatae) as var. flavandra M.P.de Vos because of the highly distinctive pilose, H-shaped leaf. The rediscovery of the taxon in the wild shows it to be a previously unrecognized member of sect. Aggregatae, distinguished by its unusual foliage and bright orange flowers. R. quartzicola was grown to flowering from seeds collected from quartz patches in southern Namaqualand and proved to be a new species of sect. Ciliatae, distinguished by its early flowering, short, subclavate leaves with reduced sclerenchyma strands, and bright yellow flowers with short bracts. R. neglecta M.P.de Vos, a rare endemic from the Kamiesberg in Northern Cape, is a later homonym for the Mediterranean R. neglecta Jord. Fourr., and the earliest name for this plant is shown to be R. speciosa (Ker Gawl.) Baker, typified by an illustration in Andrews’ The botanist’s repository. An epitype is designated to fix the application of the name. We have also examined the type illustration of R. pudica (Sol. ex Ker Gawl.) Baker, hitherto treated as an uncertain species, and are confident that it represents the species currently known as R. amoena Schltr. ex Bég., and takes priority over it as being the earlier name. The type of R. reflexa Eckl., a new name for the later homonym I. reflexa Thunb. and the basionym of R. rosea var. reflexa (Eckl.) Bég., has been mistakenly identified as an Ecklon collection but is in fact the collection that formed the basis of Thunberg’s I. reflexa. This collection is actually a form of R. flava Lam., and the name R. rosea var. reflexa is thus moved to the synonomy of that species. The variety currently known under this name should now be known as R. rosea var. muirii (N.E.Br.) Goldblatt J.C.Manning. Finally, the protologue of R. parviflora Eckl., until now treated under the synonomy of R. obscura Klatt var. obscura, is in fact consistent with R. rosea var. australis (Ewart) M.P.de Vos, and we therefore include the name in the synonomy of the latter.

Time of diversification in the Cape fauna endemisms, inferred by phylogenetic studies of the genusIselma(Coleoptera: Meloidae: Eleticinae)

The endemic diversification of the Cape zone fauna and the phylogenetic relationships among the 30 species of the blister beetle genus Iselma are investigated. We analysed morphological, molecular (mtDNA 16S) and combined datasets of characters using a number of approaches (maximum parsimony, maximum likelihood, Bayesian inference analyses). We propose hypotheses of diversification times among taxa from molecular clock analyses. Morphological and molecular analyses produced similar results. According to maximum likelihood molecular studies, radiation within the genus Iselma occurred during the Pliocene and Pleistocene, roughly contemporaneously with the shift in African climate, vegetation and faunal assemblages. Two main lineages, one Namibian and one South African, separated c. 4.9 Ma. Within the South African lineage we identify two groups of endemic species, one in Little Karoo and one that extend towards southern Namaqualand. The remaining South African groups of species are spread through Namaqualand and the southwestern Cape area. These include several endemisms, with different times of diversification during the Pleistocene, probably related in part to glacial cycles. These endemisms are distributed in small areas of the following ecosystems: coastal Strandveld, Succulent Karoo and particularly Fynbos.

New species of <i>Moraea</i> (Iridaceae: Iridoideae), with range extensions and miscellaneous notes for southern African species

Three new species are described in the largely sub-Saharan genus Moraea Mill. (± 200 spp.), all from its centre of diversity in the winter rainfall region of southern Africa. Moraea pearsonii, from Hottentotskloof near Ceres in Western Cape, flowers in late November and December when its leaves are ± dry, and has small, pale lilac, stellate flowers with the style branches each divided to the base into filiform arms. Moraea tanquana, from the Tankwa River Basin in Northern Cape, resembles the southern Namaqualand M. deserticola but has broad, plane leaves, short anthers exserted from a shallower floral cup and a short style. In section Acaules, M. longipes from Namaqualand stands out in its early flowering habit, a stem consisting of a single long intemode reaching well above the ground, short style and unusually long anthers. Moraea jarmilae described from Ox Bow, Lesotho in 2002, is conspecific with M. albicuspa and is reduced to synonymy. Significant range extensions are reported for M. elsiae, M. falcifolia, M. pseudospicata, M. spathulata, M. tricolor, M. vegeta, M. verecunda, M. vespertina and M. vlokii. A yellow-flowered morph, local in the Perdebont Valley of the Little Karoo, is reported for the first time in typically blue- to violet-flowered M. bipartita, as well as the occurrence of a hybrid swarm, rare in Moraea, between M. bipartita and M. polyanthos.

Two new species of <i>Babiana</i> (Iridaceae: Crocoideae) from western South Africa, new names for <i>B.</i> <i>longiflora</i> and <i>B.<i> </i>thunbergii</i>, and com­ments on the original publication of the genus

Babiana symmetrantha and B. virescens are two new species of section Teretifolieae of this southern African genus, now comprising 90 species. Babiana symmetrantha blooms in August and early September and is restricted to the summit of the Langberg which lies along the border of Namaqualand and the western Karoo near Loeriesfontein. One of only three species of the section with radially symmetric flowers, it is acaulescent and has linear, almost plane leaves covered with long hairs, a perianth tube 45-60(-75) mm long, and subequal, spreading tepals. Babiana virescens blooms in early winter, in May and June, and occurs in seasonally moist open ground on gentle slopes and valley bottoms in southern Namaqualand between Nuwerus and Bitterfontein. It is distinguished by the slightly misted, oblong leaves with thickened, pale margins, and the glabrous cataphvlls and leaf sheaths. The stem, which may be produced up to 100 mm above the ground, is simpleor has a single short branch and the spikes bear 2-6 greenish flowers, the tepals of which are unusually narrow and longer than the perianth tube. We also propose a new name. B tubaeformis. for the homonym B. longiflora and provide a new combination B. hirsuta based on the 1783 name Antholyza hirsuta Lam., which replaces B thunbergii Ker Gawl. (1804). Lastly, we present an argument that Babiana is correctly attributed to Ker Gawler alone and that its protologue dates from 1802 contrary to some current authorities.

Five new species of <i>Lachenalia</i> (Hyacinthaceae) from arid areas of Namibia and South Africa

Five new species of Lachenalia are described: L. aurioliae G.D.Duncan from the Little Karoo and Great Karoo, L. obscura Schltr. ex G.D.Duncan from Namaqualand, the Kamiesberg, the western Great Karoo and the Little Karoo, L. inconspicua G.D.Duncan from the Kamiesberg, western Bushmanland and southern Namaqualand, L. marlothii W.F.Barkerex G.D.Duncan from the Calvinia-Sutherland region of the western Great Karoo, and L. xerophila Schltr. ex G.D.Duncan from northwesternand central Namaqualand, and western Bushmanland.

The Geelwal Karoo heavy mineral deposit: a modern day beach placer

The Geelwal Karoo heavy-mineral placer is situated in an active beach environment along the rugged southern Namaqualand coast of South Africa. The geomorphology of the coast is controlled by resistant Precambrian and Palaeozoic basement rocks, which also dictate the narrow, elongate geometry and limited 10 km strike length of this strandline deposit. Ore reserves are small compared to the multi-million tonne analogous Quaternary sands elsewhere in the world. However, the locally high, total heavy mineral content and the favourable ore to gangue mineral ratio, coupled with the possibility of replenishment style mining, makes this an attractive resource. Garnet and ilmenite are the dominant heavy minerals followed by pyroxene, zircon, rutile and titaniferous alteration products after ilmenite. The high Ti content of ilmenite (51%) and predominantly almandine garnet suggest metamorphic source rocks, most likely part of the Namaqualand Metamorphic Complex. These rocks are considered to be the primary source. However, after numerous stages of reworking, large quantities of heavy minerals are concentrated in the Neogene marine terraces along the west coast. The 35 m terrace, a local, heavy, mineral-rich palaeostrandline, acted as a point source and supplied vast quantities to the coastal environment. A J-bay shaped headland to the south prevented excessive dispersion of the minerals by the strong northward-directed littoral drift. This allowed wave action to transport, concentrate and re-deposit the heavy minerals in their present beach environment at Geelwal Karoo.

Convergent Evolution of the 'Homeria' Flower Type in Six New Species of Moraea (Iridaceae-Irideae) in Southern Africa

Convergent Evolution of the 'Homeria' Flower Type in Six New Species of Moraea (Iridaceae-Irideae) in Southern Africa

Dehydration melting and the granulite transition in metapelites from southern Namaqualand, S. Africa

In a prograde amphibolite-granulite transition zone in the Namaqualand Metamorphic Complex, metapelites show an interbanding of the amphibolite facies association biotite+sillimanite+quartz with the granulite facies association garnet+cordierite+K-feldspar. Relict graded bedding shows that compositional banding is of sedimentary origin. The garnet-cordierite-K-feldspar gneisses contain quartzofeldspathic segregations surrounding garnets, and have more Fe-rich bulk compositions than the biotite-sillimanite schists.

The origin of the southern Namaqualand gneiss complex, South Africa, in the light of geochemical data

The Namaqualand granite-gneiss complex in South Africa covers an area of approximately 70,000 km 2. The southern portion consists of mainly mesozonal biotite gneiss and a fine-grained granulite. Geochemical data suggest that regional metamorphism and possibly partial mobilisation of mainly arkosic rocks of the Kheis System gave rise to the basement gneiss in which remnants of the transformed sediments are still preserved. There is no evidence for large-scale metasomatic granitisation which, according to previous authors, transformed the original sediments into the gneisses. Petrological considerations strongly support the conclusion that the sediments of the previously called ‘Malmesbury Formation’ cannot be the parent rocks of the gneiss complex.