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    A Probable Pollination Mode Before Angiosperms: Eurasian, Long-Proboscid Scorpionflies
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    Abstract:
    The head and mouthpart structures of 11 species of Eurasian scorpionflies represent three extinct and closely related families during a 62-million-year interval from the late Middle Jurassic to the late Early Cretaceous. These taxa had elongate, siphonate (tubular) proboscides and fed on ovular secretions of extinct gymnosperms. Five potential ovulate host-plant taxa co-occur with these insects: a seed fern, conifer, ginkgoopsid, pentoxylalean, and gnetalean. The presence of scorpionfly taxa suggests that siphonate proboscides fed on gymnosperm pollination drops and likely engaged in pollination mutualisms with gymnosperms during the mid-Mesozoic, long before the similar and independent coevolution of nectar-feeding flies, moths, and beetles on angiosperms. All three scorpionfly families became extinct during the later Early Cretaceous, coincident with global gymnosperm-to-angiosperm turnover.
    Keywords:
    Gymnosperm
    Coevolution
    Contemporary reviews of leaf responses to sunflecks indicate gymnosperms exhibit slower photosynthetic inductions times than angiosperms, but the gymnosperms were represented exclusively by conifers. I recently reported that the gymnosperm Cycas micronesica exhibited photosynthetic induction times in conformity with some of the most rapid angiosperms and opined that representatives from non-conifer gymnosperms must be added to the published conifer database before gymnosperm-wide conclusions can be formulated. Guiding principles for this urgently needed research will maximize relevance and improve accuracy of conclusions.
    Gymnosperm
    Relevance
    Conformity
    The plant resource of ornamental fern in Jiangxi Province was investigated,the results showed that there were 233 species,97 genera,47 families of ornamental ferns in Jiangxi Province,and they could be divided into 5 types(terrestrial fern,epiphytic fern,rock fern,vine fern and aquatic fern) according to the ecotype.some have local characteristics could choose for development and utilization.Some have local characteristics could choose for development and utilization.
    Ornamental plant
    Epiphyte
    Vine
    Ecotype
    Virescence
    Citations (0)
    According to surveys and statistics,there are 98 species of 49 genera of 30 families ornamental fern in Ruoliaoxian Nature Reserve.According to the ecological type,the fern can be divided into five types: Terrestrial fern,Lithophytic fern,Epiphytic fern,Aquatic fern and Vine fern.The application of each kind of fern in landscape was analyzed also.
    Epiphyte
    Ornamental plant
    Vine
    Citations (0)
    Abstract Fern accumulates radionuclides in abundance, including 137Cs. Tranfer of 137Cs and 40K in plants which have different root systems (fern or grass), or have no roots at all (moss) was compared. Samplings were performed in regions contaminated with 137Cs after Chernobyl Nuclear Power Plant (ChNPP) accident in 1994 and 1997–2000. The male fern (Dryopteris filix‐mas) most prevailing in Lithuania was studied. Fern accumulates 137Cs more effectively than grass or moss. The average 137Cs activity concentration in fern is 180±60 Bq kg−1 and the transfer factor is 0,074 m2kg−1. The fern stipe accumulates 137Cs most of all (200±90 Bqkg‐1), the transfer factor is 0,087 m2 kg−1. Accumulation of 137Cs is influenced by the content of K in the soil. 137Cs and 40K activity concentrations in fern are higher than those in the soil what shows that fern accumulates 137Cs better than 40K. Fern can clean the soil because this plant accumulates radionuclides in its stipe rather than roots.
    Pteris vittata
    Stipe (mycology)
    Transfer factor
    Frond
    Fern accumulates radionuclides in abundance, including 137Cs. Tranfer of 137Cs and 40K in plants which have different root systems (fern or grass), or have no roots at all (moss) was compared. Samplings were performed in regions contaminated with 137Cs after Chernobyl Nuclear Power Plant (ChNPP) accident in 1994 and 1997–2000. The male fern (Dryopteris filix‐mas) most prevailing in Lithuania was studied. Fern accumulates 137Cs more effectively than grass or moss. The average 137Cs activity concentration in fern is 180±60 Bq kg−1 and the transfer factor is 0,074 m2kg−1. The fern stipe accumulates 137Cs most of all (200±90 Bqkg‐1), the transfer factor is 0,087 m2 kg−1. Accumulation of 137Cs is influenced by the content of K in the soil. 137Cs and 40K activity concentrations in fern are higher than those in the soil what shows that fern accumulates 137Cs better than 40K. Fern can clean the soil because this plant accumulates radionuclides in its stipe rather than roots.
    Pteris vittata
    Stipe (mycology)
    Transfer factor
    Frond
    Sporophyte
    According to surveys and statistics, there are 161 species and 7 varieties of 72 genera of 38 families fern in Songyang, of which there are 103 ornamental species. According to the ecological type, the fern can be divided into five types: terrestrial fern, lithophytic fern, epiphytic fern, aquatic fern and vine fern. In addition, various kinds of use of ornamental fern in landscape was already probed into.
    Ornamental plant
    Vine
    Epiphyte
    Polypodiaceae
    Citations (0)
    Four kinds of gymnosperm stem's xylem was observed and researched.Finally counted and surveyed the tracheids' diameters,and the increased condiation of tracheid wall's thickness,which belonged to different of gymnosperm xylem.The gymnosperm xylem was elaborated from anatomical angle.
    Gymnosperm
    Tracheid
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