Nonvascular Plants: Mosses, Liverworts, and Hornworts
Concepts
3 Major Groups of Plants
Nonvascular Plants
Vascular Cryptograms 
Spermatophytes
These plants have neither vascular tissue nor seeds
Nonvascular plants were the first true plants to be discovered
Ex. Mosses, liverworts, and hornworts
Ex. Clubmosses, scouring rushes, and ferns
Ex. Cycads, conifers, angiosperms
These plants have both vascular tissue and seeds
These plants have vascular tissue but not seeds
Characteristics of Nonvascular Plants
Division Bryophyta
Division Hepatophyta
Division Anthocerotophyta
Hornworts
A group of small, inconspicuous thalloid plants that grow on moist soil, hidden by grasses and other herbs
They are found on roadside cuts and stable eroded soil in shade
A unique feature of the hornworts is the presence of a single large chloroplast
Liverworts
Small plants that have an alternation of heteromorphic generations
Sporophyte Generation
2 Basic Groups of Hepatic Gametophytes:
Thallose liverworts
Leafy liverworts
Mosses
Their bodies are composed of true parenchyma
Mostly terrestrial and have a cuticle over much of their bodies
Gametophytes are larger and occur inside pollen grains and ovules
Sporophytes are much smaller and have leaves and roots
Occur in all parts of the world and in almost every environment
Morphology
Gametophores
The leafy stem of many moss plants that grow close together, tightly appressed and forming dense mounds
Water Transport
Hydroids
Conduct water and dissolved materials
Leptoids
Involved in carbohydrate conduction
Rhizoids
Involved in allowing plants to migrate laterally
In both of these groups, the gametophyte phase is initiated when spores germinate and establish a small, temporary protonematal phase
Elaters
Single, elongate cells with spring-shaped walls. When the sporangium opens, the elaters uncoil pushing spores out
All liverworts=homosporous
The gametophyte is parenchymatous. They're always thin on the edges, and the center is more than 5 cells thick
The sporophytes have a foot and basal meristem, which makes them different from other plants
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