Plants are not considered organ systems. Instead, they are considered organisms, meaning they are a complete living entity composed of multiple organ systems working together.

Here's why:

* Organ systems are groups of organs that work together to perform a specific function in an organism. For example, the human digestive system is composed of organs like the stomach, intestines, and liver, all working together to break down food.

* Plants have various organ systems, just like animals. They have a root system for anchoring and absorbing water and nutrients, a shoot system for photosynthesis and reproduction, and vascular tissue for transporting water and nutrients throughout the plant.

* Each of these plant organ systems is composed of multiple organs. For example, the shoot system includes leaves, stems, and flowers, all working together for growth and reproduction.

Therefore, it's inaccurate to call a plant an organ system. A plant is a complete organism with various organ systems working together to sustain life.