08/30/04

Since vascular seedless plants possess flagellated sperm produced by their gametophytes, they are suited for life in many environments.  Moisture and proximity, however, are a factor in determining whether or not reproduction can successfully occur.⁹ 

Some whisk ferns (Psilophyta) form parasitic associations with fungi, who provide the gametophytes with nutrients for development.

Ferns (Pterophyta) employ primitive root structures known as rhizomes which spread sideways from the base of the plant into the soil, absorbing nutrients and water.  Rhizomes are not true roots, however, because they lack vascular tissue, simply absorbing water and nutrients through diffusion.  For this reasons, Ferns tend to locate themselves in shadier areas with moist soil.¹