Saturday, February 7, 2009

Lycophytes




Characteristics:

Lycophytes are vascular, seedless plants,found in/on temperate forest floors or underground.

Development and Life Cycle:


  • The lycophyte life cycle starts off with a spore that turns into a young gametophyte that releases sperm and eggs, if bisexual, and is fertilized, all of this during the haploid stage.
  • The egg then becomes a zygote and grows into a new sporophyte, and then a mature sporophyte which then releases the spores, all during the diploid stage.
  • The lycophyte reproduction cycle occurs in two different methods, the homosporous spore production and the heterosporous spore production.
  • The Homosporous spore production occurs when the sporangium in the sporophyll releases a single type of spore in a bisexual plant to fertilize itself.
  • The heterosporous spore production occurs when the megaspores and microspores, which female and male gametophytes, respectively, are released and the sperm fertilizes the egg.

One adaptation is that spores are released in clouds, improving the chances of the plants reproduction.

Examples:

An image of Isoetes Gunni.

The Isoetes gunnii is a quillwort and lives in marshy areas.