Phlophore - Phlophore

A taxonomic group based on the vegetative structure, it is a group that is distinct from stem-leaf plants. Thallous plants include algae and lichens that do not differentiate into stems or roots, and do not have conductive tissue or reproductive organs. There is almost no differentiation of organs or tissues, but some brown algae have slightly differentiated leaf-like photosynthetic organs, stems, and roots. The hairs on the underside of the thallus of mosses function as roots, and differentiation of primitive conductive tissue is also seen, but they are not fully adapted to life on land, and water is essential for their habitat, and moisture is also required for the fertilization of eggs. In terms of the characteristics of flagella and chlorophyll formation, which are important in systematic classification, thallous plants can be said to be a collection of heterogeneous taxa.

[Akiko Sugiyama]

Source: Shogakukan Encyclopedia Nipponica About Encyclopedia Nipponica Information | Legend

栄養体の体制に基づく分類群で、茎葉植物に対する一群をいう。葉状植物は茎や根を分化せず、通道組織や生殖器官もみられない藻類、地衣類などを含む。器官や組織はほとんど分化しないが、褐藻植物には、葉のような光合成器官、茎や根などをわずかに分化するものもある。苔(たい)類の葉状体下面の毛は根の働きがあり、原始通道組織の分化もみられるが、陸上生活への適応は十分ではなく、生活の場には水が不可欠で、卵の受精にも水分が必要である。系統分類上重要とされる鞭毛(べんもう)やクロロフィル形成の特徴からみると、葉状植物はそれぞれ異質の分類群の集まりといえる。

［杉山明子］

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