A useful plant is one that serves a purpose or provides benefits to people, such as food, medicine, materials for shelter or clothing, or improving the environment by absorbing pollutants or providing habitat for wildlife. It is also considered useful if it has a positive impact on human health, nutrition, or well-being.
Musterd is a plant whose seeds and leaves are useful to us
Long answer
fruit
Variegated leafed plant is useful for demonstrating that chlorophyll is needed for photosynthesis because variegated leaf is a plant which uses chlorophyll to absorb light so it can get its color
The value of a power plant at the end of its useful life is known as its salvage value. Salvage value is the estimated resale value of the plant's components and materials once it is no longer operational.
maths is useful to tell scientific theories becaus
Floods are useful by how plant fertilize it help the plants.
Musterd is a plant whose seeds and leaves are useful to us
five ways how plants are useful to us
Long answer
soil and plant
Variations in organisms can certainly be useful in plant and animal breeding. These variations lead to adaptions to the environment.
It can tell you if you have a temperature...
they tell you where you are
A touch-me-not plant is useful for entertainment, as a 'pet' or for illustrating the unusual feature of fast movement in a plant.
rainwater
Feed some people