What is a contact herbicide primarily known for?

A contact herbicide is primarily known for causing localized injury to plant tissue. This type of herbicide works by damaging the parts of the plant that it directly comes into contact with, such as the leaves or stems. The action is non-systemic, meaning it does not move throughout the plant to affect other parts such as the roots or the inner tissues. Instead, it specifically targets and damages the areas where it is applied, leading to the death of the plant in those affected areas.

The other options do not accurately define the primary characteristic of contact herbicides. For instance, affecting all parts of the plant systemically would refer to a systemic herbicide, which is absorbed and transported throughout the whole plant. Promoting rapid growth of a plant is unrelated to the function of a contact herbicide; rather, it contradicts its purpose, which is to kill or damage unwanted vegetation. Lastly, while some contact herbicides may have minimal effects on beneficial insects, this is not a defining characteristic of contact herbicides; the primary focus of such products is on plant damage.