Non Vascular Plants

Non Vascular Plants (Non- Tracheophytes): Bryophytes 

Main Features; 

• The group are largely confined to damp conditions which allow the passage of sperm to the archegonia and the flow of nutrients to individual’s cells. 

• Non- Vascular plants have recently been divided into 3 phyla which are started below (Originally one Bryophyte) and are classified according to the shape and the growth pattern of the sporophyte 

• They DON’T PRODUCE SEEDS due to them nurturing their zygotes in the tissues of the parent plant.

• They rely on the surface film of water to act as a transport system as tracheophytes are not huge plants therefore do not develop a transport system, so film of water transports all the nutrients which enters by diffusions. Some can tolerate very dry conditions but still relay on a moisture film for growth and reproduction.

Examples of Non vascular plants

Bryophyte (Mosses)

Formerly Class: Bryopside (musci)

First Fossil to date back 415 Mya.

Ø  Differentiated into simple leaf- like structures that can form stems

Ø  Some species with cells called hydroids which ‘die’ and become tubes through which water can pass- first origins of transport systems.

Ø  There are not lignified* but are otherwise analogous to xylem in the vascular plants.

Sporophyte is stalked with a spore capsule 

Hepatophyta (Liverworts)

Formerly class: Hepaticopsida

Thought to have been the first to evolve.

Ø  Some are leafy and prostrate, other are plate-like.

Ø  Sporophyte is not stalked (Although gametophyte which bears it may be)

Ø  Rhiziods (‘Rootlike structures’) are unicellular filaments

Anthocerophyta (Hornworts)

Formerly class: Anthocertopsida

Ø  Gametophytes always thalliod (not differenced into steam or leaf)

Ø  Sporophyte* stalked with needle like capsule- capable of indefinite growth.

Ø  Process stomata and form mutualistic relationship with cyanobacteria*

Form some of the largest non-tracheophytes- up to 20cm 

*SPOROPHYTE; is the diploid multicellular stage in the life cycle of a plant or alga. It develops from the zygote produced when a haploid egg cell is fertilized by a haploid sperm and each sporophyte cell therefore has a double set of chromosomes, one set from each parent.

*CYANOBACTERIA:  bacteria but are capable of photosynthesis. 

*LIGNIGIED: make rigid and woody by the deposition of lignin in cell walls.

LIFE CYCLE

Life Cycle Haploid/ Diploid Stage; Alternation of the generations between haploid gamete- producing Gametophyte and diploid spore-producing sporophytes, the gametophytes being the more prominent of the two

Life cycle of Non Vascular plants from Life, the science of biology

Sporophytes attached to the, and derive nourishment from, the gametophytes.

-          Male gametes (Mobile) are produced in an ANTHERIDUM

-          Female gametes are produced in an ARCHEGONIUM

Ø  The male swims in a surface film of a water and fertilise the female egg in situ. After syngamy, the sporophyte grows out of the gametophyte and derives its moistures and nutrients from it.

Remaining attached to the gametophyte throughout its life