Gemma - gemma

Japanese: 無性芽 - むせいが（英語表記）gemma

This refers to the part of a plant that has separated from the main plant and differentiated to become a new individual. For example, the small buds that form in the cup-shaped bodies of Marchantia polymorpha are a typical example. In the case of lichens, they are called needle buds or lobe buds (→ powder buds), but these can also be considered asexual buds in the broad sense. In fungi, especially Saprolegnia and Mucor, parts of the mycelium often thicken under unfavorable conditions and later re-establish new individuals from them; this is called asexual buds or chlamydospores. The vegetative reproductive mechanism of seed plants, the "bulk", can also be considered a gemma (originally meaning "bud"), but the current usage is centered on spore-producing plants, as mentioned above.

Source: Encyclopaedia Britannica Concise Encyclopedia About Encyclopaedia Britannica Concise Encyclopedia Information

Japanese:

植物体の一部が本体から離れて，新しい個体になるように分化した体の部分をいう。たとえばゼニゴケの杯状体中に生じる小芽などが代表的。地衣類の場合には特に針芽または裂芽 (→粉芽 ) と呼んでいるが，これらも広義の無性芽といえる。なお菌類，特にミズカビ，ケカビなどにおいては菌糸の一部が不遇状態のもとで厚膜化し，のちにそれから新個体が再起する場合がしばしばみられるが，これを無性芽または厚膜胞子という。種子植物の栄養生殖機構である「むかご」なども，本来は gemma (原義は「芽」) といえるが，現在の用法は，上記のように胞子植物を中心としている。

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