Nonvascular plants do not have the specialized structure know as xylem , which is found in vascular plants. Xylem aids in the movement of water and nutrients throughout a plant. Nonvascular plants have existed for millions of years , and they can be aquatic or land plants. Nonvascular land plants, called bryophytes , likely diverged from aquatic plants such as algae about million years ago.
The nonvascular characteristic is similar to that of distant green algae ancestors. Since nonvascular plants lack circulatory systems or tracheids , nutrients and water must move between cells. Bryophytes include algae, mosses the phylum Bryophyta , liverworts the phylum Marchantiophyta and hornworts the phylum Anthocerotophyta.
Liverworts represent the first bryophytes, dating as far back as the Ordovician Period. The fossil record is limited due to the fact that bryophytes do not contain lignin. Bryophytes must live in moist environments because they do not have vascular systems.
This way they can directly absorb nutrients into cells. Bryophytes do not have traditional kinds of leaves, stems and true roots like the more evolved land plants.
Because of this, bryophytes tend to be low-growing. Individual shoots are densely packed into cushions, tufts or mats. They spread across their substrate of ground, trees or rocks as mats and mounds. Two broad types of nonvascular plants are the leafy shoots with flattened organs such as mosses and leafy liverworts, and the thalloid plants, such as hornworts and some types of liverworts.
Nonvascular plant features include leaf-like structures that are photosynthetic, stems, the thallus and rhizoids to anchor to the available substrate. The thicker the shoots, the better water retention they have. Nonvascular plants alternate their generations for reproduction. Their haploid gametophyte generation sexual reproduction form is long, while their sporophyte generation asexual reproduction form is brief.
Water is required for their sperm to fertilize gametes. The main form of nonvascular plants is that of the gametophyte, with a less prominent sporophyte. The sporophyte relies on the gametophyte form for its water and nutrition.
Nonvascular plants do not reproduce in the same manner as vascular plants. Instead of using seeds, flowers or fruit, bryophytes grow from spores. Chapter Population Genetics. Chapter Evolutionary History. Chapter Plant Reproduction. Chapter Plant Responses to the Environment. Full Table of Contents. This is a sample clip. Sign in or start your free trial. JoVE Core Biology. Previous Video Next Video. Next Video Embed Share. Plant life on Earth consists of nonvascular, seedless vascular, and seed plants.
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Also available from Amazon , Book Depository and all other good bookstores. Know the answer? Why not test yourself with our quick 20 question quiz. There was an error submitting your subscription. Please try again. Email Address. Search for:. In all three groups of non-vascular plants the gametophyte dominates the life cycle. Note that in this group, structures that produce sperm are known as antheridia and the structures that produce eggs are known as archegonia. View animation of moss life cycle.
Figure 10 Non vascular plants. Liverwort with insert showing the short lived sporophyte state.
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