Which plant serves as an example of a simple perennial?

Curly dock is an example of a simple perennial because it has a growth habit that allows it to live for more than two years and produces new shoots from its established root system each growing season. Simple perennials generally have a defined structure, with a single main shoot that develops and dies back in the winter, only to regrow in spring. Curly dock has a rosette form in its early stages, and its root system enables it to survive adverse conditions, contributing to its classification as a simple perennial.

Other choices, while also perennial plants, showcase different growth forms and characteristics. Virginia creeper is a vine that can spread aggressively and is often considered a climbing perennial. Horsetail has a more complex growth form with multiple stems that grow from a rhizome, while big bluestem is a tall grass characterized by its extensive root system and clumping growth, which further diverges from the simple structure found in curly dock. Thus, curly dock best embodies the characteristics of a simple perennial among the options provided.