What is the scientific name of the Pecan, Texas state tree?
Through the long span of geological time, major groups of vascular plants have risen to dominance, only to decline to a minor remnant in the earth’s flora. The angiosperms or flowering plants, are the group that is now in the full flush of its evolutionary development. We are living in the “age of the angiosperms”. There are more than 250,000 species, grouped into 12,500 genera and about 300 families. Angiosperms dominate in almost every terrestrial habitat, the tundra and northern coniferous forests being among the few exceptions. Because of their abundance and widespread distribution, angiosperms constitute a major part of the environment of other organisms. As such, they have exerted a profound effect on other organisms, particularly the animals that feed on them. For example, the evolution of herbivorous mammals has correlated with the worldwide spread of grasses, legumes, and other herbs. Most modern birds have evolved as organisms that feed on either the seeds, fruits, or buds of