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Weeds belongs to the class Angiosperm (flowering plants) which have two subclasses: Monocotyledoneae (Monocots) and Dicotyledoneae (dicots). On the basis of the habitat, they are divided into terrestrial and aquatic categories, and on the basis of the duration of life they are divided into annuals, biennials and perennials. Next is Aquatic weeds (hydrophytes or water inhabitants) are classified into three types, viz. Submerged, emersed and floating. Submerged aquatics are anchored to the bottom of the habitat e.g. a ditch, a grow entirely beneath the surface of the water. Emersed ones have their roots beneath the surface of the water, but the leaves and stems are above the water-line. Floating weeds or surface aquatics either float freely on the water or float only in a limited area. There is still another group of weeds known as the parasitic weeds. These are of two kinds: the total parasites and the partial parasites. |
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