9 resultados para Hymenophyllaceae.


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Crepidomanes minutum (Hymenophyllaceae) is here identified and recorded from Mauritius for the first time. The Mauritian specimens, in addition to those of La Reunion observed at low to middle elevations, are easily distinguished from populations observed outside the Mascarene Archipelago by their dwarfed size and rarity of the stipe proliferation that usually characterizes this species. We thus describe a new variety in this species for the Mascarene Islands.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Southern China, especially Yunnan, has undergone high tectonic activity caused by the uplift of Himalayan Mountains during the Neogene, which led to a fast changing palaeogeography. Previous study shows that Southern China has been influenced by the Asian Monsoon since at least the Early Miocene. However, it is yet not well understood how intense the Miocene monsoon system was. In the present study, 63 fossil floras of 16 localities from Southern China are compiled and evaluated for obtaining available information concerning floristic composition, stratigraphic age, sedimentology, etc. Based on such reliable information, selected mega- and micro-floras have been analysed with the coexistence approach to obtain quantitative palaeoclimate data. Visualization of climate results in maps shows a distinct spatial differentiation in Southern China during the Miocene. Higher seasonalities of temperature and precipitation occur in the north and south parts of Southern China, respectively. During the Miocene, most regions of Southern China and Europe were both warm and humid. Central Eurasia was likely to be an arid center, which gradually spread westward and eastward. Our data provide information about Miocene climate patterns in Southern China and about the evolution of these patterns throughout the Miocene, and is also crucial to unravel and understand the climatic signals of global cooling and tectonic uplift.

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The Longling Coal Mine (W. Yunnan) is situated in an area of substantial geotectonic activity. Its Late Pliocene palynoflora is of considerable interest, since the area represents a centre of biodiversity. Eighty-two palynomorphs belonging to 61 families were recovered from the lignite. The palynoflora is dominated by angiosperms (68.3%), with ferns (24.4%), gymnosperms (4.9%) and algae (2.4%). Comparisons indicate that most of the palynoflora was derived from the Montane Humid Evergreen Broad-leaved Forest, with lesser contributions from the Tsuga dumosa Forest and Evergreen Coniferous Broad-leaved Mixed Forest, as well as the Montane Mossy Evergreen Broad-leaved Forest. This indicates that the Late Pliocene climate was cooler than that of the present. In the course of the accumulation of the lignite, the climate underwent five major phases of warming and cooling.

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A second part of this title was published in v.5 of the Nederlandsch kruidkundig archief, 1864. cf. Pritzel. Thesaurus literaturae botanicae.

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Iridescent blue leaf coloration in two neotropical ferns, Danaea nodosa (L.) Sm. (Marattiaceae) and Trichomanes elegans L. C. Rich. (Hymenophyllaceae), is caused by thin film constructive interference. The ultrastructural basis for the film in D. nodosa is multiple layers of cellulose microfibrils in the adaxial cell walls of the adaxial epidermis. The apparent helicoidal arrangement of the fibrils is analogous to similar color production in arthropods. In T. elegans the blue-green coloration is caused by the remarkably uniform thickness and arrangement of grana in specialized chloroplasts adjacent to the adaxial wall of the adaxial epidermis. The selective advantage of this color production, if any, is unknown but apparently different from that previously studied in Selaginella.