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Sydney, Australia

Dunk C.W.,La Trobe University | Lebel T.,National Herbarium | Keane P.J.,La Trobe University
Mycorrhiza | Year: 2012

The occurrence of the exotic ectomycorrhizal fungus Amanita muscaria in a mixed Nothofagus-Eucalyptus native forest was investigated to determine if A. muscaria has switched hosts to form a successful association with a native tree species in a natural environment. A mycorrhizal morphotype consistently found beneath A. muscaria sporocarps was examined, and a range of morphological and anatomical characteristics in common with those described for ectomycorrhizae formed by A. muscaria on a broad range of hosts were observed. A full description is provided. The likely plant associate was determined to be Nothofagus cunninghamii based upon anatomy of the roots. Analysis of ITS-1 and ITS-2 regions of nuclear ribosomal DNA sequences confirmed the identities of both fungal and plant associates. These findings represent conclusive evidence of the invasion of a non-indigenous ectomycorrhizal fungus into native forest and highlight the ecological implications of this discovery. © 2011 Springer-Verlag. Source

Jayasuriya K.M.G.G.,University of Peradeniya | Baskin J.M.,University of Kentucky | Baskin C.C.,University of Kentucky | Fernando M.T.R.,National Herbarium
Research Journal of Seed Science | Year: 2012

Non dormancy, three of the five classes of dormancy and orthodox and recalcitrant storage behavior occur in seeds of Fabaceae. The aim of the study was to characterize whole-seed dormancy and storage behavior in seeds of three tropical species of Derris (Fabaceae), which are lianas. Seed Moisture Content (MC); effects of drying and low temperature on viability; water-uptake of intact and scarified seeds; and effects of scarification, fruit coat removal and GAS on germination were determined. Seed coat anatomy was studied to check for evidence of physical dormancy. Seeds of D. parvifolia and D. scandens had low MC and those of D. trifoliata high MC. D. trifoliata seeds were sensitive to both drying and low temperature storage. Seeds of D, scandens were water-impermeable and those of D. parvifolia and D. trifoliata water-permeable. D. parvifolia seeds germinated without treatment, whereas those of D. scandens required scarification. Removal of fruit coat and application of GAS overcame dormancy in D. trifoliata seeds. A palisade layer was present only in the seed coat of D. scandens. D, trifoliata seeds are recalcitrant and those of the other two species orthodox. Seeds of D. parvifolia are nondormant and those of D. scandens and D, trifoliata have Physical (PY) and Physiological (PD) dormancy, respectively. The ecological implications of nondormancy/dormancy in relation to orthodoxy/recalcitrant seed storage behavior in tropical lianas are discussed. © 2012 Academic Journals Inc. Source

Henriette E.,University of Seychelles | Larridon I.,Ghent University | Morel C.,National Herbarium | Goetghebeur P.,Ghent University | And 2 more authors.
Phytotaxa | Year: 2015

Knowledge of the monocot flora of the Seychelles remains relatively weak and new taxonomic studies, including both herbarium specimens and field observations, are needed. Extensive new explorations in the key biodiversity areas of the Seychelles granitic islands resulted in the discovery of an unknown species of Costularia. After careful examination of existing specimens and literature within that genus, we concluded that the unknown plant corresponds to the type of Cladium xipholepis, a species endemic to the Seychelles which had previously been confused and put into synonymy with two unrelated taxa, i.e. the other Seychelles endemic Costularia hornei and the Mascarene species C. melicoides. These confusions were due to the immature state of the type of Cladium xipholepis, which was the only known specimen of the species. The name Cladium xipholepis is here resurrected and combined in the genus Costularia, adding one endemic species to the flora of the Seychelles. In addition, a detailed description is provided, correcting important errors regarding diagnostic characters made in the original description. Costularia xipholepis is a rare species, occurring on lower montane inselbergs of Mahé Island, and is here proposed as endangered (EN) according to IUCN Red List categories and criteria. It is morphologically closely related to C. pantopoda var. baronii from Madagascar. The other Seychelles endemic Costularia, C. hornei (lectotype designated here), has no close relative and belongs to a group distributed in South-East Asia. We discuss these results in relation to the origins of the flora of the Seychelles. Finally, the previously thought endemic variety Costularia hornei var. rectirhachilloidea was also reviewed and we consider it to be identical to the type variety, but based on specimens at an earlier stage of spikelet development. These discoveries, along with other preliminary studies, indicate that more studies are needed to review the monocots of the Seychelles, particularly Cyperaceae, Orchidaceae and Poaceae. © 2015 Magnolia Press. Source

Barkworth M.E.,Utah State University | Jacobs S.W.L.,National Herbarium
Telopea | Year: 2010

We endorse recognition of four morphologically and cytologically distinct genera for Australasia's native Triticeae: Australopyrum, Stenostachys, Anthosachne and Connorochloa. To encourage adoption of this recommendation, we present a key to all genera of Triticeae found in Australasia, descriptions of the native genera, keys to their species, the new combinations required to implement our generic recommendations (Anthosachne falcis, A. fertilis, A. longiseta, A. multiflora var. kingiana, A. plurinervis, A. rectiseta, A. solandri and Stenostachys enysii), and representative line drawings. These and additional identification resources are available on the web at http://herbarium.usu.edu/triticeae. We also lectotypify Agropyron velutinum Nees. © 2011 Royal Botanic Gardens and Domain Trust. Source

Cabrera J.,University Mainz | Jacobs S.W.L.,National Herbarium | Kadereit G.,University Mainz
Telopea | Year: 2010

Camphorosmeae (Chenopodiaceae, formerly Sderolaeneae) are widespread across all states of Australia. Molecular data revealed that the Australian Camphorosmeae represent a monophyletic lineage comprising 147 currently recognised species, 145 of which are endemic to Australia. Like their Eurasian relatives most Australian Camphorosmeae are well-adapted to dry and saline environments, and most species are distributed in semi-arid or arid landscapes of the Eremaean area of central and western Australia. The historical biogeography of the Australian Camphorosmeae is analysed using an ETS phylogeny of the group and DIVA. We found that diversification of the tribe started at the end of the Miocene, and that radiation took place during the Pliocene, probably driven by the aridification of Australia during this time. Southern west Australia probably served as the ancestral area, and we hypothesise that the ancestors of Australian Camphorosmeae were already adapted to dry and saline conditions and might have been distributed in coastal or saline inland habitats. Successful dispersal and establishment of Camphorosmeae in the then newly developed arid regions was probably enhanced by niche pre-emption. Our timing of the radiation of this drought-adapted lineage and the directions of its dispersal support the hypothesis that the aridification of Australia started during the Late Miocene and arid areas expanded during the Pliocene from the west to the east and then north. © 2011 Royal Botanic Gardens and Domain Trust. Source

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