What type of herbicide is toxic to some plant species while not affecting others?

The correct choice is selective herbicide because these types of herbicides are designed to target specific plant species while leaving others unharmed. This selectivity is often based on the physiological differences between plants, allowing certain herbicides to disrupt vital processes in specific weed species without affecting desirable plants. This feature makes selective herbicides beneficial for turf and ornamental applications, where maintaining the health of desirable plants is crucial while managing weed populations.

In contrast, non-selective herbicides affect all plant species they come into contact with, making them unsuitable for use in areas where you want to preserve ornamental plants or turf. Systemic herbicides are taken up by the plant and transported throughout its tissues, but they are categorized based on how they work rather than their selectivity. Contact herbicides only kill the parts of the plant they touch and might affect any plant they come into contact with, lacking the targeted approach offered by selective herbicides.