noun Date: 1816 any of various freshwater green algae (order Charales) that have a thallus differentiated into rhizoids and stems with whorls of branchlets and that are often encrusted with calcareous deposits
STONEWORT
Meaning of STONEWORT in English
Merriam Webster. Explanatory English dictionary Merriam Webster. Толковый словарь английского языка Мерриам-Уэбстер. 2012