The plant body that we think of as the fern reproduces by spores. Spores usually are resistant to many of the things that would kill the plant itself. This is especially important in the Southwest, where long, hot dry periods are the rule rather than the exception. The spore eventually germinates into a tiny plant that most people wouldn't recognize as a fern; this, in turn, eventually produces the fern-looking fern. When we look at more advanced plants, resistance to adverse environmental conditions is handed over to the seed.
While most people will readily agree that seeds are marvelous devices
for insuring reproduction, they might be even more impressed if they knew that each
seed contains parts of three different generations of plants. The embryo encased within
the seed is the latest generation, while the stored food that it'll depend on
during germination comes courtesy of its true mother—a tiny plant that was entirely
surrounded by grandmother throughout its short life. And part of grandmother stays
around to form the outer, protective seed coat. Now, that's real
togetherness!
Listen to the Audio (mp3 format).
Contributor: Arthur H. Harris, Laboratory for Environmental Biology, Centennial Museum, University of Texas at El Paso.
Desert Diary is a production of KTEP National Public Radio at the University of Texas at El Paso.