From Thomas Björkman:
Don Rakow and Rajeev Arora (left), Department of Horticulture, Iowa State University, evaluate variation in cold injury among the Rhododendron species on Comstock Knoll in Cornell Plantations.
Arora, an expert on cold hardiness in woody plants and particularly the control of deacclimation in the spring, presented Monday’s Department of Horticulture seminar.
This species showed photobleaching of the midrib from when the leaf was curled at low temperature (thermonasty) and only the midrib exposed on a sunny but frigid day this past winter.