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| domain = Eukaryota | regnum = Archaeplastida | unranked_phylum = Chlorobionta | unranked_subphylum = Streptophyta | unranked_classis = Embryophyta | unranked_subclassis = Tracheophyta | unranked_subclassis_authority = Sinnott, 1935〔Sinnott, E. W. 1935. ''Botany. Principles and Problems'', 3d edition. McGraw-Hill, New York.〕 | subdivision_ranks = Divisions † Extinct | subdivision = * Non-seed-bearing plants * * †Rhyniophyta * * †Zosterophyllophyta * * Lycopodiophyta * * †Trimerophytophyta * * Pteridophyta * * †Progymnospermophyta * Superdivision Spermatophyta * * †Pteridospermatophyta * * Pinophyta * * Cycadophyta * * Ginkgophyta * * Gnetophyta * * Angiosperms (Magnoliophyta) }} Vascular plants (from Latin ''vasculum'': duct), also known as tracheophytes (from the equivalent Greek term ''trachea'') and also higher plants, form a large group of plants that are defined as those land plants that have lignified tissues (the xylem) for conducting water and minerals throughout the plant. They also have a specialized non-lignified tissue (the phloem) to conduct products of photosynthesis. Vascular plants include the clubmosses, horsetails, ferns, gymnosperms (including conifers) and angiosperms (flowering plants). Scientific names for the group include Tracheophyta〔Abercrombie, Hickman & Johnson. 1966. ''A Dictionary of Biology.'' (Penguin Books〕 and Tracheobionta.〔(【引用サイトリンク】title=ITIS Standard Report Page: Tracheobionta )〕 ==Characteristics== Vascular plants are distinguished by two primary characteristics: # Vascular plants have vascular tissues which distribute resources through the plant. This feature allows vascular plants to evolve to a larger size than non-vascular plants, which lack these specialized conducting tissues and are therefore restricted to relatively small sizes. # In vascular plants, the principal generation phase is the ''sporophyte'', which is usually diploid with two sets of chromosomes per cell. Only the germ cells and gametophytes are haploid. By contrast, the principal generation phase in non-vascular plants is the ''gametophyte'', which is haploid with one set of chromosomes per cell. In these plants, only the spore stalk and capsule are diploid. One possible mechanism for the presumed switch from emphasis on the haploid generation to emphasis on the diploid generation is the greater efficiency in spore dispersal with more complex diploid structures. In other words, elaboration of the spore stalk enabled the production of more spores and the ability to release them higher and to broadcast them farther. Such developments may include more photosynthetic area for the spore-bearing structure, the ability to grow independent roots, woody structure for support, and more branching. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「vascular plant」の詳細全文を読む スポンサード リンク
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