The first angiosperms may originally have been small, treelike plants in tropical regions, but eventually they began diversifying rapidly into other habitats where early gymnosperms flourished. South African botanist William Bond proposed the “slow seedling” hypothesis to help explain this evolutionary change, and botanists continue to refine it. The hypothesis proposes that angiosperms were able to encroach on many habitats where ancient gymnosperms lived, in part because flowering species increasingly evolved adaptations that made them fast-growing herbaceous plants. Gymnosperms grow more slowly. Based on your reading of this chapter and Chapter 29, what are some structural and biochemical features of gymnosperms (such as conifers) that might result in slower growth, putting them at a competitive disadvantage in this scenario?