Browsing by Author "Klak, Cornelia"

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    Hidden Diversity—A New Speciose Gall Midge Genus (Diptera: Cecidomyiidae) Associated with Succulent Aizoaceae in South Africa
    (Multidisciplinary Digital Publishing Institute, 2022-01-10) Dorchin, Netta; van Munster, Stephany; Klak, Cornelia; Bowie, Rauri C. K.; Colville, Jonathan F.
    Aizoaceae (Caryophyllales) constitute one of the major floral components of the unique Greater Cape Floristic Region (GCFR), with more than 1700 species and 70% endemism. Within succulent Aizoaceae, the subfamily Ruschioideae is the most speciose and rapidly diversifying clade, offering potential niches for the diversification of specialized herbivorous insects. Nevertheless, insect diversity on these plants has not been studied to date, and knowledge of gall-inducing insects in the Afrotropics is generally scarce. Our recent observations indicate that succulent Aizoaceae in the GCFR support a rich and largely unstudied community of gall midges (Diptera: Cecidomyiidae). Here, we provide a first report of their diversity with a description of a new genus, Ruschiola Dorchin, and ten new species, based on morphological and molecular analyses of material collected during a three-year targeted survey across major GCFR vegetation types. A high degree of morphological uniformity in Ruschiola suggests recent diversification and necessitated the use of molecular data and laboratory rearing from host plants to verify species boundaries and host ranges.
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    Phylogeny and character evolution in the Lampranthus-group (Aizoaceae-Ruschioideae)
    (2001) Klak, Cornelia; Hedderson, Terry A; Linder, H P
    The phylogenetic position of the Lampranthus - group (Ruschioideae, Aizoaceae), with particular emphasis on the large genus Lampranthus, was studied using morphological characters and DNA sequence from the trnL - trnF region of the chloroplast genome, the nuclear ribsomal internal transcribed space (ITS) region and the 5S non-transcribed spacer. The phylogenies 59 species in the 29 genera of succulent Aizoaceae, including two species from subfamily Mesembryanthemoideae, are presented.
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    A synopsis of the genus Octopoma N.E.Br. (Ruschioideae) using morphology, 5S NTS and psbA - trnH spacer regions
    (2003) Muzila, Mbaki; Hedderson, Terry A; Klak, Cornelia
    The genus Octopoma N. Br. is nested within the Ruschioideae in Aizoaceae. It has been thought that eight species make up the genus. The classification was based mainly on the possession of eight locules. This study was, therefore, undertaken to test the monophyly of the genus, and to draw up new taxonomic circumscriptions.
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    Systematics of psilocaulon N.E.BR. (Aizoaceae)
    (1997) Klak, Cornelia; Linder, H P
    On the basis of herbarium, living and pickled material the morphology and systematics of Psilocaulon N. E. Brown sensu Ihlenfeldt & Bittrich is investigated. Thirteen species (including one insufficiently known species) are recognized: P. articulatum, P. bicorne, P. coriarium, P. dimorphum, P. dinteri, P. foliosum, P. gessertianum, P. granulicaule, P. junceum, P. leptarthron, P. parviflorum, P. salicornioides, P. subnodosum. Species of Mesembryanthemum, Prenia, Brownanthus, Aspazom and Aptenia are used as outgroups in a cladistic analysis of Psilocaulon. The monophyly of Psilocaulon is demonstrated. As a result P. rapaceum Jacq. is excluded and transferred to Caulipsolon Klak gen. nov. The position of Psilocaulon and the monotypic genus Caulipsolon within the subfamily Mesembryanthemoideae is discussed. However, relationships of Psilocaulon and Caulipsolon to other genera remain obscure, since no synapomorphies were found to indicate sister relationships. More sampling among outgroups and/or a future molecular study may help to elucidate relationships among the genera of the Mesembryanthemoideae. Geographical distribution patterns for all species and the number of species per half-degree grid square are given. It is discussed how species diversity and geographical distribution in Psilocaulon contrasts with or corroborates existing ideas of centres of diversity and distribution patterns in the Mesembryanthema. Each species is described in detail. A description of the genera Psilocaulon and Caulipsolon is given and a key to the species is provided. Material examined is cited and full synonomy is given.
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    Three new species and two new combinations in the Aizoaceae from the Western and Northern Cape of South Africa
    (2010) Klak, Cornelia
    Three new species of Aizoaceae from the Western Cape are described. Octopoma tanquanum Klak and Vlokia montana Klak are dwarf shrubby or mat-forming succulents which belong to the Ruschieae in the Ruschioideae. Mesembryanthemum knolfonteinense Klak of the Mesembryanthemoideae is a geophyte. Octopoma tanquanum inhabits relatively low lying arid areas within the Tanqua Karoo and the Little Karoo and is thought to be closely allied to the two species of Octopoma found in the Little Karoo. Both V. montana and M. knolfonteinense grow at relatively high altitudes within the fynbos biome. In addition, Ruschia littlewoodii L.Bolus is transferred to Phiambolia, and two new combinations are made in Antimima for Ruschia hexamera L.Bolus and Ruschia radicans L.Bolus.