What is the difference in alga, weed and seaweed?


Would you please explain me the difference between alga, weed and seaweed? May I use one instead another in all cases?
  • lazarus1907

    Senior Member
    Spanish, Spain
    The Algae (plural of alga) are a group of plants, and the seaweed is just one kind of alga.
    Weed is a more general word, and normally refers to those annoying plants that grow uninvitedly in the garden.


    Senior Member
    English, Canada
    Alga is a organism that builds up in water. It has no roots or leaves. It's microscopic, but when many of them grow together you will see a green film which is very slippery.

    Weed(s), are generally land-based and unwanted plants. One man's 'weed' may be another man's delight. Here, dandelions are considered weeds.

    Seaweed is, as its name suggests, a plant that grows in water.

    So no, each is a very separate thing and none of them may be used interchangeably.