rhododendrons

An adaptation allows broad-leaved evergreens like rhododendrons to thrive in the doubly-challenging conditions of damp soil and freezing temperatures.

A phenomenon called "thermonasty" causes rhododendron leaves to curl up when it’s really cold out. This adaptation allows these broad-leaved evergreens to thrive in the doubly-challenging conditions of damp soil and freezing temperatures.

The rhododendrons that bloom once a year at a New Hampshire state park are coming out, but vegetative growth may be hiding some of them.A New Hampshire…