<p>Rhododendron (<i>Rhododendron maximum</i>), Lackawanna State Forest, Lackawanna County.
</p>
A cold-hardy species, <i>R. maximum</i> responds to subfreezing temperatures by curling, folding down, and clamping shut its foliage. This action helps protect the shrub from the desiccating effects of cold air. (According to my GPS unit, the air temperature was 9ºF [–13ºC] at the time.)
<a rel="nofollow" class="external text" href="https://www.flickr.com/people/14922165@N00">Nicholas A. Tonelli</a>
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<a href="//commons.wikimedia.org/wiki/Flickr" class="mw-redirect" title="Flickr">Flickr</a>: <a rel="nofollow" class="external text" href="https://www.flickr.com/photos/14922165@N00/8413647837">Nature's Thermometers</a>