By Susan Milius
In a rare test of paternal behavior in plants, snow buttercup flowers kept from following the sun produced less-viable pollen than unfettered flowers did. Also, in maternal flowers receiving pollen, the grains germinated better if these blooms, too, were free to track the sun, according to Candace Galen of the University of Missouri in Columbia.
Sun tracking turns up in a handful of plant families, mostly among species in cold locales, says Galen. She and Maureen Stanton of the University of California, Davis study snow buttercups (Ranunculus adoneus) that poke flowers up through melting snow in the Colorado Rockies. The researchers left some blooms free and kept others from tracking the sun by slipping a drinking straw around their stems, constraining them in one orientation.