The genus Tristachya (Poaceae: Panicoideae) in Madagascar (original) (raw)
Trichanthecium tenerium (Poaceae: Panicoideae), a new species from Guinea-Conakry
Kew Bulletin, 2020
Trichanthecium tenerium Xanthos, a new species from Guinea-Conakry, is described and illustrated. Trichanthecium tenerium is at present known only from two uninhabited sandstone table mountains in the Kounounkan Massif, Forécariah Prefecture. The species is assessed under the IUCN category Endangered. A key to the annual species of Trichanthecium is provided.
Classification and Biogeography of Panicoideae (Poaceae) in the New World
Aliso, 2007
Brazil is the center of diversity of New World panicoids with 741 species (54.6% of all species). The distributions of endemic and restricted taxa were analyzed in terms of biogeographical regions and Kranz syndrome. Amphitropical disjuncts and widespread species are also discussed.
Conserving Madagascar's Plant Diversity: Kew's Madagascar Threatened Plants Project
Curtis's Botanical Magazine, 2004
This paper outlines the work of the Madagascar Threatened Plants Project (TPP), partly financed by the Friends of Kew. Several species of orchids, palms and succulents are being studied and propagated as trial subjects. At the same time funds are used to improve the infrastructure of Malagasy Institutions actively involved in plant conservation, and to train post-graduate students who will be the next generation of Malagasy botanists, conservationists and horticulturists.
Phylogenomics and taxonomy of Lecomtelleae (Poaceae), an isolated panicoid lineage from Madagascar
Annals of Botany, 2013
Aims An accurate characterization of biodiversity requires analyses of DNA sequences in addition to classical morphological descriptions. New methods based on high-throughput sequencing may allow investigation of specimens with a large set of genetic markers to infer their evolutionary history. In the grass family, the phylogenetic position of the monotypic genus Lecomtella, a rare bamboo-like endemic from Madagascar, has never been appropriately evaluated. Until now its taxonomic treatment has remained controversial, indicating the need for re-evaluation based on a combination of molecular and morphological data. † Methods The phylogenetic position of Lecomtella in Poaceae was evaluated based on sequences from the nuclear and plastid genomes generated by next-generation sequencing (NGS). In addition, a detailed morphological description of L. madagascariensis was produced, and its distribution and habit were investigated in order to assess its conservation status. † Key Results The complete plastid sequence, a ribosomal DNA unit and fragments of low-copy nuclear genes ( phyB and ppc) were obtained. All phylogenetic analyses place Lecomtella as an isolated member of the core panicoids, which last shared a common ancestor with other species .20 million years ago. Although Lecomtella exhibits morphological characters typical of Panicoideae, an unusual combination of traits supports its treatment as a separate group. † Conclusions The study showed that NGS can be used to generate abundant phylogenetic information rapidly, opening new avenues for grass phylogenetics. These data clearly showed that Lecomtella forms an isolated lineage, which, in combination with its morphological peculiarities, justifies its treatment as a separate tribe: Lecomtelleae. New descriptions of the tribe, genus and species are presented with a typification, a distribution map and an IUCN conservation assessment.
2009
The Galoka mountain chain, comprising principally the Galoka and Kalabenono massifs, situated at the northern edge of the Sambirano Region in NW Madagascar is an area that was virtually unknown botanically. It was visited three times between 2005 and 2007 as part of a floristic inventory. Both massifs contain the last remaining primary forests in the Galoka chain, which extends parallel to the coastline from South of Ambilobe to North of Ambanja. Several new species have been discovered amongst the collections, eight of which are described here.
Plant Ecology & Diversity, 2013
Background: Deforestation processes and species extinction on islands have made them the focus of substantial efforts to create and strengthen local environmental organisations, establish new protected areas and improve natural resource management. In Madagascar, despite promising new policies, the flora and fauna are under serious threat. More than 80% of the island shows a significant loss of natural plant cover. Current levels of diversity reflect natural disturbance regimes, with fire representing one of the more important factors. Aims: We compared two new protected areas (Ibity and Itremo) with different environmental and management contexts to identify the roles and impacts of the environmental conditions and the different types of management applied by their respective local communities on vegetation. Both areas have extensive stands of tapia (Uapaca bojeri) woodland. Methods: Herbaceous vegetation surveys were carried out enumerating 16 1-m 2 quadrats in each of 10 sites on Ibity and seven on Itremo to characterise plant community composition and structure, complemented by tree and shrub surveys within three 40 × 40 m quadrats at each site. Results: Floristic richness was higher at Ibity. Populations of U. bojeri were better conserved at Itremo. Conclusions: While the total exclusion of fire is impracticable, careful management should enable the maintenance of natural conditions and at least lead to a reduction in the impacts on the structure of tapia woodland vegetation.
The Isalo National Park is the fourth largest and one of the earliest protected areas in Madagascar. It was created in 1962, and covers an area of about 82 000 ha. The whole park (especially its southern section) is intensively managed by the local community and frequented by tourists. This may create many conflicts between the objectives of nature protection and human activities such as tourism, cattle grazing and gathering of useful plants. Although scientists frequently visit the area (comp. Andrew and Hawkins 1999; Nicoll and Langrand 1989), the fauna and flora of Isalo are still insufficiently described. There are no ecological papers related exclusively to the Isalo Massif (Andrew and Hawkins 1999), and thus all information should be useful for future study. That is why I have decided to present a short characteristic of the vegetation of this area, which summarises my observations carried out in January 2002.
Ecological survey of the Lycophytes and Ferns of the Vohimana Reserve, Madagascar
Plant Ecology and Evolution, 2012
Based on the authors' recent collections and on older herbarium specimens (PC, TAN, EGR), the species of Marchantiidae (Marchantiopsida, Marchantiophyta) of Madagascar are reported with their description based on Malagasy specimens. A distribution map for each taxon is provided. Among the fifteen taxa identified, six are newly recorded for the island, including a new synonymy: Asterella coronata (Steph.) H.A.Mill = Asterella bachmannii (Steph.) S.W. Arnell. Most of Marchantiidae live in xeric areas (Riccia species, Exormotheca pustulosa Mitt.) or in exposed, only temporarily wet stations (Plagiochasma, Asterella). This preliminary study shows the evidence of under-prospection of such areas in Madagascar for bryophytes and the need of taxonomic work to clarify some genera (Riccia, Asterella, Plagiochasma) and to confirm the species hitherto reported.
New species of Dypsis and Ravenea (Arecaceae) from Madagascar
Kew Bulletin, 2010
Fourteen new species of palms (Arecaceae) from Madagascar are described and named, based on material collected over the last 15 years. Twelve species belong to the genus Dypsis, namely D. andilamenensis Rakotoarin. & J. Dransf., D. anjae Rakotoarin. & J. Dransf., D. betsimisarakae Rakotoarin. & J. Dransf., D. culminis Rakotoarin. & J. Dransf., D. dracaenoides Rakotoarin. & J. Dransf., D. gautieri Rakotoarin. & J. Dransf., D. gronophyllum Rakotoarin. & J. Dransf., D. jeremiei Rakotoarin. & J. Dransf., D. metallica Rakotoarin. & J. Dransf., D. reflexa Rakotoarin. & J. Dransf., D. sancta Rakotoarin. & J. Dransf. and D. vonitrandambo Rakotoarin. & J. Dransf. and two species belong to the genus Ravenea: R. beentjei Rakotoarin. & J. Dransf. and R. hypoleuca Rakotoarin. & J. Dransf. Despite the fact that most of these species have been recorded from protected areas that are difficult to access in the eastern region of Madagasacar, they are all threatened. Based on IUCN categories and crite...
Adansonia, 2012
Two new species of Turraea L. are described from northern Madagascar, T. andriamiarisoana Callm., Phillipson & Lowry, sp. nov. and T. buerkii Callm., Phillipson & Lowry, sp. nov., both endemic to a region bounded by four relatively well-studied protected areas (Tsaratanana, Manongarivo, Marojejy and Anjanaharibe-Sud). The region harbors extensive low to high elevation humid forest that was botanically virtually unknown until recently. The new species differ from each other and from other members of the genus in Madagascar by leaf features, flower colour, length of the staminal appendices, and the shape and the pubescence of the ovary. Line drawings are provided for both of the new taxa, along with discussions of their morphological affinities and preliminary risk of extinction assessments.