Major Plant Divisions

Bryophytes are non vascular plants due to their lack of vascular tissue. It is also referred to as embryophytes.  Some of the bryophytes do not have tisse necessary for the transport of water. Bryophytes are also determined to not be a natural group. They do not produce flower or seeds. Three lineages of Bryophytes are marchantiophyta, bryophyta and anthocerotophyta. Bryophytes lack necessary tissue compared to other plants such as lignin or branched sporophytes. They can aslo be dioicous or monoicous.

Pteridophytes contain xylem and phloem which classifies it as vascular plants. They  do not produce flowers or seeds. This characteristic adds on to their classification as vascular cryptogams, which results in their reproduction and dispersion of spores.  They consist of two groups; Lycopodiophyta and of Ferns. It also contains a freeliving gametophyte stage. In terms of the pteridophytes sexuality, there are two; dioicous and monoicous.

Gymnosperms are seed bearing plants. Conifers are the largest group of gymnosperms.  It is believed that gymnosperms developed in the carboniferous period. Gymnosperms are crucial to economic use due to its use as lumber.( pine, fir, cedar) It has as short live. Its seeds are enclosed in an ovule.  They are non flowering seed plants. Gymnosperms means, "naked seed."

Angiosperm are also known as flowering plants.  They are seed producing plants. They are different than gymnosperms due to characters such s flowers and endosperm within seeds. There are eight groups of angiosperms; amborella, nymphaeales, austrobaileyales, chloranthales, magnoliidae, monocotyledonae, ceratophyllum and eudicotyledonae.  Angiosperms can also refer to the Divison Anthopyta. Their distinguishing factor comes from it seeds which are enclosed within fruits. There are two main classes: class monoctyledones and class dicotyledones. Angiosperms have roots, stems, leaves, and flowers. They also have alternation of generations.  The special thing about angiosperms is their double fertilization.



http://bryophytes.plant.siu.edu/

http://www.anbg.gov.au/fern/taxa/pteridophyte.html
http://biology.clc.uc.edu/courses/bio106/angio.htm