To solve this problem, we need to identify which plant does not exhibit plasticity. Plasticity in plants refers to the ability to change their morphology or physiology in response to environmental conditions.$\newline$Let's analyze each option:$\newline \bullet$Cotton:$\newline$ - Cotton plants can exhibit plasticity by altering their growth patterns based on environmental factors such as light and water availability.$\newline \bullet$Coriander:$\newline$ - Coriander, like many herbs, can show plasticity in leaf shape and size depending on growing conditions.$\newline \bullet$Buttercup:$\newline$ - Buttercup plants are known for their ability to adapt to different environments, showing plasticity in their growth forms.$\newline \bullet$Maize:$\newline$ - Maize, or corn, is a crop plant that is generally bred for specific traits and shows less plasticity compared to the other plants listed. It is more uniform in its growth and development.$\newline$Therefore, the plant that does not show plasticity is Maize.$\newline$This corresponds to Option 4.