What is an indicator plant?

An indicator plant is specifically identified as a species that signals the presence of specific pest populations or diseases. These plants exhibit symptoms, such as wilting, discoloration, or changes in growth patterns, that can alert growers and pest managers to the presence of certain pests or pathogens in the environment. By monitoring these plants, professionals can take proactive measures to manage pest populations or address diseases before they spread to other plants in the area.

The other choices do not accurately describe the role of an indicator plant: while some plants may thrive in poor soil conditions or be chosen for their decorative value, this does not relate to the plant's ability to indicate pest presence. Additionally, being immune to pests does not confer the plant with any diagnostic capability; rather, an indicator plant provides critical information about the health of a surrounding ecosystem.