Inquiry- and course-based research pedagogies have demonstrated effectiveness for preparing undergraduate biology students with authentic scientific skills and competencies, yet many students lack the experience to engage successfully in open-ended research activities without sufficient scaffolding and structure. Further, curricula for student-centered laboratory activities are lacking for several biological disciplines, including plant biology and botany. In this article, I describe a semester-long structured-inquiry research curriculum developed for a plant biology course taught to second-year biology students that integrates key elements of inquiry and discovery while providing a structured approach to gaining research skills. In the research project, students collect leaves from woody dicot plants across a range of environments that are characterized by different mean annual temperatures, and investigate the relationship between various leaf characteristics and temperature. Curricular materials are provided to teach skills in scientific paper reading, field data collection, data processing including microscopy and image analysis, quantitative data analysis in R, biological inference, and scientific writing. This comprehensive, ready-to-implement curriculum is suitable for plant biology, botany, and plant ecology courses and is particularly valuable for students with no prior research experience.