What describes a systemic (translocated) herbicide?

A systemic (translocated) herbicide is characterized by its ability to move within the plant after it is absorbed, reaching the specific site of action where it can effectively disrupt the plant's growth processes. Once the herbicide is taken up, usually through the leaves or roots, it travels through the plant's vascular system, allowing it to affect not just the area where it was applied but also other parts of the plant, including the roots and stems. This systemic action is particularly useful for controlling perennial or deeply-rooted weeds, as it can target the entire plant and not just the foliage.

The other options describe different herbicide characteristics that do not relate to the systemic nature. For instance, targeting only leaf tissues does not encompass the capability to reach deeper into the plant. Quick evaporation pertains to the volatility of the herbicide, which does not indicate its ability to move within the plant, while remaining in the soil refers to the herbicide’s mobility in the environment rather than within the plant itself. Thus, the defining feature of a systemic herbicide is its translocation throughout the plant, enabling effective control of unwanted vegetation.