College of Engineering, Chubu University, Kasugai, Aichi 487, Japan
(Received April 27, 1996; Accepted June 28, 1996)
Keywords: Plasticity, Shoot Morphology, Light Capture by Leaves, Optimization
Abstract. Diversity and plasticity in shoot morphology of herbs are examined by using model plants that are constructed mathematically on the computer and specified by observational data. The analysis is done theoretically by use of the optimization theory, based on factors which may influence shoot morphology, i.e., i) solar radiation captured by leaves, ii) effective usage of resource among leaves, stems, and veins, iii) seasonal change in growth schedule. I find that the solar radiation flux per leaf area per day is nearly constant for three different kinds of phyllotactic patterns (i.e., spiral, distichous, and whorled). Based on observational data, I examine the plasticity in shoot morphology due to changes in living environment, and find that the agreement between observational and theoretical results is quite good.