Dr. Uma Ganesan/Olympus Bioscapes Digital Imaging Competition
ANSWER: An oak leaf
The Northern Hemisphere is home to about 450 species of oak. This micrograph image of an oak leaf¹s surface reveals bunches of tiny hairs called trichomes, which concentrate light for photosynthesis and reduce water loss. Oak leaves also contain tannins, which can poison horses that have a taste for foliage.