Bryophytes may be desiccation tolerant, surviving
dry tissues and beginning photosynthesis upon
rehydration, or they may be drought avoiders, using
structural adaptations and life cycle stages to escape
having a dry leafy plant. The presence of a central
strand does not seem to correlate with the degree of
internal conduction, but habitat does. Xeric bryophytes
are more likely to have greater internal conduction and
faster external conduction than mesic and hydric taxa.
It is possible that the central strand may serve as a water
reservoir in some taxa.