22 research outputs found
Three new species and two new combinations in the Aizoaceae from the Western and Northern Cape of South Africa
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
Systematics of psilocaulon N.E.BR. (Aizoaceae)
Bibliography: p. 131-140.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
Phylogenetic placement and generic re-circumscriptions of the multilocular genera Arenifera, Octopoma and Schlechteranthus (Aizoaceae: Ruschieae): Evidence from anatomical, morphological and plastid DNA data
"Ruschieae is the largest tribe in the highly speciose subfamily Ruschioideae (Aizoaceae). A generic-level phylogeny for
the tribe was recently produced, providing new insights into relationships between the taxa. Octopoma and Arenifera are woody
shrubs with multilocular capsules and are distributed across the Succulent Karoo. Octopoma was shown to be polyphyletic in the
tribal phylogeny, but comprehensive sampling is required to confirm its polyphyly. Arenifera has not previously been sampled
and therefore its phylogenetic placement in the tribe is uncertain. In this study, phylogenetic sampling for nine plastid regions
(atpB-rbcL, matK, psbJ-petA, rpl16, rps16, trnD-trnT, trnL-F, trnQUUG-rps16, trnS-trnG) was expanded to include all species
of Octopoma and Arenifera, to assess phylogenetic placement and relationships of these genera. Three phylogenetic analyses
were carried out, maximum parsimony, maximum likelihood and Bayesian inference. Leaf anatomical sections were studied
to further inform generic circumscriptions. The phylogenies showed Octopoma to be polyphyletic, with the type, O. octojuge,
and the related O. nanum, resolved as sister to Zeuktophyllum and Smicrostigma, while the other species were placed in the
Conophytum-clade. Arenifera was also shown to be polyphyletic, with the type, A. pillansii, placed in the xeromorphic-clade,
and the remainder of the species recovered among the Octopoma species in the Conophytum-clade (forming the Octopoma
subglobosum-Arenifera spinescens subclade). Generic affinities of the O. subglobosum-A. spinescens subclade were assessed
in relation to the sister taxon Schlechteranthus. The leaf anatomy was found to be informative within the study group. Bladder
cells were observed in Arenifera pillansii, a hypodermis in Little Karoo Octopoma (O. octojuge, O. nanum, O. quadrisepalum)
and epidermal cells forming blunt papillae in Schlechteranthus and the O. subglobosum-A. spinescens subclade. Upon assessment
of the anatomical, morphological and phylogenetic data, Schlechteranthus is here expanded to include the species in
the O. subglobosum-A. spinescens subclade. Eight new combinations are made in Schlechteranthus. As a result, Arenifera is
again monotypic and the circumscription of Octopoma is refined to include three species restricted to the Little Karoo. Two
subgenera within Schlechteranthus s.l. (subg. Schlechteranthus, subg. Microphyllus) are erected to accommodate differences
in leaf size, capsule size, closing body size and locule number."Web of Scienc
Hidden Diversity—A New Speciose Gall Midge Genus (Diptera: Cecidomyiidae) Associated with Succulent Aizoaceae in South Africa
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
A taxonomic backbone for the global synthesis of species diversity in the angiosperm order Caryophyllales
The Caryophyllales constitute a major lineage of flowering plants with approximately 12500 species in 39 families. A taxonomic backbone at the genus level is provided that reflects the current state of knowledge and accepts 749 genera for the order. A detailed review of the literature of the past two decades shows that enormous progress has been made in understanding overall phylogenetic relationships in Caryophyllales. The process of re-circumscribing families in order to be monophyletic appears to be largely complete and has led to the recognition of eight new families (Anacampserotaceae, Kewaceae, Limeaceae, Lophiocarpaceae, Macarthuriaceae, Microteaceae, Montiaceae and Talinaceae), while the phylogenetic evaluation of generic concepts is still well underway. As a result of this, the number of genera has increased by more than ten percent in comparison to the last complete treatments in the Families and genera of vascular plants” series. A checklist with all currently accepted genus names in Caryophyllales, as well as nomenclatural references, type names and synonymy is presented. Notes indicate how extensively the respective genera have been studied in a phylogenetic context. The most diverse families at the generic level are Cactaceae and Aizoaceae, but 28 families comprise only one to six genera. This synopsis represents a first step towards the aim of creating a global synthesis of the species diversity in the angiosperm order Caryophyllales integrating the work of numerous specialists around the world
Embryo and caryopsis morphology of danthonoid grasses (Arundinoideae: Poaceae): important characters for their systematics?
Phylogeny and character evolution in the Lampranthus-group (Aizoaceae-Ruschioideae)
Bibliography: leaves 159-182.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