Talk about the subphylum of Angiosperms.

The main feature is the typical flower containing the reproductive organs. Angiosperms are the most diverse group, and the most advanced of plant kingdom. They include both herbaceous and woody plants. In angiosperms the bi-integumented ovule are enclosed in a protective envelope, the carpel, more or less closed in an ovary. After fertilization, the ovary becomes a fruit and the ovule a seed. This group is characterized by a particular mode of fertilization: double fertilization. Wood is mainly comprising heterogenous real vessels and fibers.