1 - Plant Hormones
This site provides extensive information which is a requisite for plant hormone research.
2 - Role of Auxin, Gibberellin and Ethylene in the Size, Pattern,
and Orientation of Regenerative Tracheids
Pine trees as used as a model for illustrating the role of individual hormones.
3 - Botany Tutorial
Your personal tutor includes a discussion of plant growth.
4 - A Start at a Comprehensive Theory of Plant Hormones
An overview of the hormonal control of plant growth is presented.