stonewort
Học thuậtThân thiện
Definition
Noun: 1. A type of freshwater green alga: A stonewort is any of various submerged aquatic algae belonging to the family Characeae, typically of the genus Chara. They are characterized by a central stem with nodes from which whorls of slender, branch-like filaments grow. They are often rough or gritty to the touch because they frequently become encrusted with deposits of calcium carbonate (lime).
Examples of Usage
- Noun:
- The clear lake bottom was covered with dense beds of stonewort.
- Biologists study stonewort as an important indicator of water quality.
- The rough texture of the stonewort is due to its calcified outer layer.
Advanced Usage
- Ecological Role: Stoneworts are considered a keystone species in some freshwater habitats, providing food and shelter for invertebrates and small fish.
- Fossil Record: Ancient relatives of modern stoneworts, known as charophytes, are significant in the fossil record and are studied in paleobotany.
Variants and Related Words
- Charophyte (n): The broader scientific group (division Charophyta) to which stoneworts belong; includes both living species like and their fossil ancestors.
- Nitella (n): Another genus within the Characeae family, closely related to and also commonly referred to as stonewort or brittlewort.
Synonyms
- Brittlewort: A common name for some species of stonewort, referring to their fragile, brittle texture.
- Chara: The primary genus name, often used interchangeably with "stonewort" in scientific and aquatic contexts.
Notes on Meaning
The term "stonewort" specifically refers to the living, calcified algae. It is not used to describe the limestone deposits themselves, which are a byproduct of the alga's growth. The "wort" part of the name is an old English word for "plant" or "herb," seen in other plant names like "liverwort."
Noun
- any of various submerged aquatic algae of the genus Chara having nodes with whorled filamentlike branches; usually encrusted with calcium carbonate deposits