December 4

The rhododendron throughout town are more conspicuous, in part because their deep green and broad leaves stand distinct against the background of stems and branches, the neighboring trees and bushes whose leaves have fallen away. It is almost as if the rhododendron is indifferent to the change of seasons, carrying on much as it has done since we first took notice of it last spring, when the purple, pink and white blossoms were nearly overwhelming.

The buds that will become next spring’s flowers sit idly now, fattened just slightly and a pale tan, waiting until warming conditions spur them to mature.

All is not quiet however, and here is where the rhododendron is curious. In the warming day, when temperatures run above approximately 35 degrees, the leaves are full and positioned nearly perpendicular to the stem. At freezing they begin to noticeably droop, and when the thermometer falls below 25 degrees the leaves curl closed. Colder yet and the curl tightens, concentrating the green color into drooping cylinders that appear lifeless.

Early mornings this time of year find them tightly formed, yet as the day progresses and the feeble sun helps modestly to push the air above freezing, the plant responds – opening leaves slowly and causing them to extend.

Why they do this isn’t really as important as is the wonder that they do, these living thermometers.