University of Maryland
Umbc/plant Growth and Development
A good description of the growth and changes in plants from the seed through the adult plant. College level discussion that includes the chemicals involved in the regulation of plant growth.
Iowa State University
Iowa State University: How a Corn Plant Develops
The Iowa State University provides a good description of the development of an important crop plant. The overview compares favorably with the development of any plant.
University of Illinois
University of Illinois Extension: In Search of Green Life
A very simple introduction to the various types of growth and reproductive styles of common plants.