White Poplar, Populus alba
Salicaceae or Willow Family
 

Tall tree with rough gray bark.  Leaves are triangular, with very large teeth, and are not opposite each other on the twigs.  Flowers are catkins which appear in the spring before the leaves.

An alien tree, often planted, and persisting in the Park from earlier cultivation.  It spreads easily by sending up suckers from the roots.  A large beautiful specimen grows near the picnic table north of the Outdoor Classroom; the suckers it sends up are mostly chopped down in mowing the meadow there.

The triangular toothed leaves are distinctive and the best way to identify it.  In the spring, the flowers are are a good clue.