Definition

1. Noun:
   • Azolla (duckweed fern, mosquito fern): A very small, free-floating aquatic fern. It often forms dense green or reddish mats on the surface of calm water in ponds, lakes, and rice fields.
   • A type of aquatic plant: Refers specifically to plants of the genus Azolla, which have a symbiotic relationship with nitrogen-fixing bacteria.

Usage Examples

• Noun:
  • Mặt hồ phủ đầy một lớp bèo dâu xanh mướt. (The lake surface was covered with a lush green layer of azolla.)
  • Bèo dâu được sử dụng như một loại phân bón xanh trong canh tác lúa. (Azolla is used as a green fertilizer in rice cultivation.)
  • Khi thời tiết lạnh, bèo dâu thường chuyển sang màu đỏ. (When the weather is cold, azolla often turns red.)

Advanced Usage

• "bèo dâu cánh": A more specific term sometimes used, emphasizing its floating, wing-like structure.
• Cultural/Agricultural Context: In Vietnam, "bèo dâu" is not just a plant name but is strongly associated with sustainable agriculture, particularly in rice paddies, due to its ability to fix nitrogen and improve soil fertility.

Variants and Related Words

• Bèo: A general term for small, free-floating aquatic plants (duckweeds, ferns like azolla).
• Bèo tấm (Lemna minor): Another common type of small floating plant (duckweed), often confused with but biologically distinct from "bèo dâu".
• Bèo hoa dâu: A less common variant name for the same plant, highlighting its potential to flower.

Synonyms

• Azolla (Scientific/Botanical term)
• Duckweed fern (Common English name)
• Mosquito fern (Common English name, as dense mats can prevent mosquito breeding)

Related Phrases/Idioms

• "Nhanh như bèo gặp nước" (As fast as duckweed meeting water): An idiom describing something that spreads or grows very rapidly. While "bèo" here is generic, "bèo dâu" is a prime example of such fast-growing aquatic vegetation.
• "Sống kiểu bèo dâu": A metaphorical phrase describing a rootless, drifting lifestyle, floating wherever the current takes one, akin to the plant.

1. Azolla