Definition

1. Noun:
   • Lichen: A composite organism that arises from algae or cyanobacteria living among filaments of multiple fungi species in a symbiotic relationship. Lichens are commonly found growing on rocks, tree bark, or soil in various environments.

Usage Examples

• Noun:
  • Địa y mọc trên những tảng đá cũ. (Lichens grow on old rocks.)
  • Màu xám của địa y trên thân cây cho thấy không khí ở đây khá trong lành. (The gray color of the lichen on the tree trunk indicates the air here is quite clean.)
  • Các nhà khoa học nghiên cứu địa y để đánh giá mức độ ô nhiễm. (Scientists study lichens to assess pollution levels.)

Advanced Usage

• As an indicator species: Lichens ("địa y") are highly sensitive to air pollution, especially sulfur dioxide. Their presence, abundance, or absence is used in bio-monitoring.
  • Sự vắng mặt của địa y trong thành phố là một dấu hiệu của ô nhiễm không khí. (The absence of lichens in the city is a sign of air pollution.)

Variants and Related Words

• Địa y học (n): Lichenology (the scientific study of lichens).
• Dạng địa y (n): Lichenized form (referring to the form or state of being a lichen).

Synonyms

• Tên khoa học/Ký hiệu: Lichen (the direct English equivalent and scientific term). There is no common, non-scientific Vietnamese synonym for this specific organism.

Related Phrases/Compounds

• Cộng sinh địa y (n): Lichen symbiosis (referring to the symbiotic relationship within a lichen).
• Quần thể địa y (n): Lichen community.

Notes on Meaning

• The word "địa y" is a specific biological/ botanical term. It does not have other common metaphorical or idiomatic meanings in everyday Vietnamese. Its usage is primarily scientific or descriptive of nature.
• It is a compound word from "địa" (earth, ground) and "y" (a Sino-Vietnamese element meaning "clothing" or "covering"), describing its appearance as a crust-like covering on surfaces.

1. (thực vật) lichen