sudd

…Even outside of high moors, emerging plants such as reeds and wild rice can break away from the shore and become floating islands. In the tropics and subtropics, floating islands called sudds are widely seen, consisting of floating plants such as water hyacinth and duckweed, and emergent plants of the Poaceae and Cyperaceae families, and can grow so large that they can become an obstacle to ship navigation. It is also known that plants that grow on the exposed lake or river bottom during the dry season break away from the bottom and become floating islands during the rainy season. …

*Some of the terminology that mentions "sudd" is listed below.

Source | Heibonsha World Encyclopedia 2nd Edition | Information

…高層湿原以外でも，ヨシ，マコモなどの抽水植物が岸から離れて浮島となる場合がある。熱帯･亜熱帯では，ホテイアオイ，ボタンウキクサなどの浮遊植物やイネ科･カヤツリグサ科の抽水植物からなり，浮芝suddとよばれる浮島が広く見られ，船の航行に障害となるほど巨大に発達する場合がある。乾季に露出した湖底･河底に生えた植物が雨季の増水時に底から離れて浮島となる場合も知られている。…

※「sudd」について言及している用語解説の一部を掲載しています。

出典｜株式会社平凡社世界大百科事典 第２版について | 情報