Abstract
Here I develop a geometry—based quantitative theory of energy partitioning between seed production and rhizome production in energy—limited herbaceous rhizomatous perennial plants. This theory makes two basis predictions. The first prediction concerns species in which additional energy devoted to rhizome production substantially increases the leaf area index of the genet. In such species, the functional relationship between seed production and leaf area index should be well approximated by a steep power law with a slope > 2. The second prediction concerns plants in which increased energy devoted to rhizomes increases the radial growth rate of clones much more strongly than it increases leaf area index and in which genets self—thin in response to crowding. In such plants, the ratio of seed production to rhizome production should be relatively constant across environments and should be strongly influenced by the relationship between the level of investment in rhizomes per ramet and the length of the resulting rhizomes. An investment ratio on the order of 1:2 is often to be expected.