Question

A weed , which has invaded many forest lands of India is
A) Parthenium hysterophorus
B) Chenopodium album
C) Lantana camara
D) Eichhornia crassipes

Answer 1

Hint: Weeds are unwanted and undesirable plants which interferes with the utilisation of land and water resources and adversely affects the desirable crops / vegetation/ forests. Any plant may become weed if it is not desirable in that particular place or time.

Complete answer:
A) Parthenium is also called carrot grass and it is noxious weed which hampers the growth of the indigenous vegetation . It causes milk disease in livestock when they consume it. In human beings they mainly cause allergy which include respiratory problems.
B) chenoppdium alba: it is also known as pigweed. It is mainly present as a weed in the crops (mainly winter crops).
C) Lantana camara ,noxious weed which was introduced as ornamental plant in India , spreaded all over the area, especially in the forest . It releases special kinds of chemicals called Allelochemicals which prevent the germination of any kind of seed around it.
D) Eichornia crassipes (also known as ‘Terror of bengal’) are the weed which was first introduced in india as ornamental plant in 1896 from brazil but now it has become the most problematic weed of lakes. It is very difficult to get rid of them.

Hence, the correct answer is option (C)

Note: There are many ways to control weeds, Like spraying chemicals ($2,4 - D$,Paraquat, Sodium arsenite etc). Weeds can also be controlled by biological methods like, Lantana camara can be controlled by beetles such as Octoma and Vroplata, Eichornia crassipsis can be effectively controlled by Ducks.