Botanists Try to Get Seeds of Rare Shrub to Germinate Using Blowtorch and Boiling Water
Posted on October 12, 2011
Scientists are having a tough time trying to get seeds of the rare Michaux's sumac (Rhus michauxii) to germinate. The native shrub is one of the rarest shrubs in the southeastern United States. Botanists have exposed the hard, thick-coated seeds to boiling water, dry heat up to 284 degrees Fahrenheit and flames from a propane blowtorch to try to coax them into germination. Nothing has worked.
Michaux's sumac grows only in areas with few trees where the vegetation has been disturbed, so it has long been assumed that its seeds germinate naturally following exposure to the high temperatures of a brush or forest fire. The shrub's decline has been linked to the prevention and suppression of brush and forest fires by humans.
In a series of germination experiments, scientists exposed different sets of Michaux's sumac seeds to dry heat temperatures of 140, 176, 212, 248 and 284 degrees Fahrenheit, some sets for 5 minutes and other sets for 10 minutes. The researchers found that temperatures above 212 degrees F. killed the seeds. Lower temperatures had virtually no impact on breaking the seed's dormancy. The highest germination rates of 30% occurred after sulfuric acid was poured on the seeds and allowed to scarify (dissolve and weaken) the seed coats.
Scientists are going to feed the seeds to birds next. "We are going to feed the seeds to quail and wild turkey to determine if that breaks the seed dormancy," says Jay F Bolin, a research associate with the Department of Botany at the Smithsonian's National Museum of Natural History and an assistant professor at Catawba College in Salisbury, N.C.
The paper "Germination of the federally endangered Michaux's sumac (Rhus michauxii)," authored by Jay F Bolin, Marcus E Jones (Norfolk Botanical Garden, Norfolk Va.,) and Lytton J Musselman (Old Dominion University, Norfolk, Va.) appeared in the Summer 2011 issue of Native Plants Journal.