We've all heard of the person so conservative that he wears both suspenders and a belt. In a human, that's considered a bit extreme. In some plants, though, that principle may mean the difference between successful reproduction and dying without issue. These plants regularly hedge their bets by having more than one way to reproduce. Most plants reproduce sexually, eggs and sperm joining to form seeds. This is risky, though; pollination may fail to occur, and too many creatures find seeds scrumptious.
The fall-back position? Vegetative reproduction. That is, reproduction
by portions of the plant other than the male and female parts. Some plants, such as
strawberries, send out runners called stolons that contact the ground and root, each
rooting eventually forming a new, separate plant. Others send out underground stems, or
rhizomes, that periodically sprout, forming new plants. And then there's the
primitive way favored by such trees as cottonwoods; a broken off limb, partially buried
in river sand, merely grows new roots, becoming a new individual. Gives the phrase
"breaking up" a whole new meaning!
Contributor: Arthur H. Harris, Laboratory for Environmental Biology, Centennial Museum, University of Texas at El Paso.
Desert Diary is a joint production of the Centennial Museum and KTEP National Public Radio at the University of Texas at El Paso.