A species can be defined as

• A. a single plant
• B. a group of plants that are alike in almost every feature and consistently produce like plants
• C. a group of plants that are unrelated
• D. a set of plants used for ornamental purposes

Answer: (B)

A species is a group of individuals that resemble each other in most features and can interbreed to produce offspring that also resemble the parents. In practical terms for horticulture, this means plants within a species share a consistent set of characteristics and keep those traits across generations, indicating a cohesive group with a shared gene pool. That’s why this definition fits best: it combines visible similarity with reproductive compatibility to maintain a distinct group over time.

A single plant is just one member, not the whole group. A group of plants that are unrelated wouldn’t share a common lineage or the ability to produce like offspring. A set of plants used for ornamental purposes describes usage, not the biological relationship or reproductive behavior that defines a species.