stoneworts; charophytes
Refers to the class Charophyceae, a group of green algae. Used in biological and botanical contexts.
Stoneworts are a group of algae that inhabit fresh water.
From 車軸藻 (しゃじくも, 'stonewort', literally 'axle weed') + 類 (るい, 'group, class'). The derivation of 車軸藻 is uncertain; it may refer to the plant's whorled branches resembling wheel spokes.