Institution: | (1) Department of Botany-Microbiology and Oklahoma Biological Survey, University of Oklahoma, Cross Hall, Norman, Oklahoma 73019, USA;(2) Botany Department, Stockholm University, SE-106 91 Stockholm, Sweden;(3) Missouri Botanical Garden, P. O. Box 299, St. Louis, Missouri 63166, USA;(4) Samuel Roberts Noble Electron Microscopy Laboratory, University of Oklahoma, Norman, Oklahoma 73019, USA |