What is defined as a decumbent plant?

A decumbent plant is characterized by stems that grow horizontally or flat along the ground while the tips may rise upwards. This growth form allows decumbent plants to spread effectively over the surface, often providing a dense cover that can be advantageous in various ecological settings. These plants may root at the nodes where they touch the soil, increasing their stability and ability to gather resources. The definition aligns precisely with the description provided in the correct answer choice, making it the appropriate choice for understanding the morphology of such plants.

The other descriptions do not fit the definition of a decumbent plant. For example, a plant that grows only in water describes a specific habitat requirement and does not reflect the growth habit related to being decumbent. Similarly, a plant that grows vertically without support describes an upright growth form, fundamentally different from a decumbent structure. Lastly, a plant always found in rocky areas relates to its habitat preference rather than its growth form, further distinguishing it from the definition of decumbency.