1Received for publication Jan. 6, 1982. The assistance of Janet Finley, Margaret Gregory, Mark Leopold, and Robert Perrone is gratefully acknowledged. Supported by Grants G5105004, G5115003, and G5115212, U.S. Department of Interior, Office of Surface Mining, and by grants from the Horticultural Research Institute and Sierra Chemical Company.
The cost of publishing this paper was defrayed in part by the payment of page charges. Under postal regulations, this paper therefore must be hereby marked advertisement solely to indicate this fact.
2Department of Horticulture and Landscape Architecture. Present address: Studebaker Nurseries Inc., 11140 New Carlisle Road, New Carlisle OH 45344.
