This poster reports findings from a pilot study of a preliminary version of a CENS middle school inquiry module. The purpose of the pilot was to elicit students’ conceptions of plant evolution, especially leaf structure-function relationships in different environments. Pre-tests of students’ knowledge about plants and plant evolution confirmed our expectations that they lacked knowledge about leaf structure and function and about plant evolution. Post-tests, following approximately 13 hours of instruction, showed significant learning about leaf structure and function, but not plant evolution. Also, students performed better on short-answer questions on a post-test than on an essay that demanded they use conceptual knowledge to explain plant adaptation across environments. These results imply that a major design effort for CENS educational materials must be to help students integrate factual knowledge into coherent conceptual frameworks.