Leaf Desciptions

alternate - petioles attach at different points
opposite - petioles attach at the same point on opposite sides

simple - one single leaf attaches to petiole
compound - one petiole has many small leaflets
lobes - leaf has a deeply wavy margin, the indentations are called sinuses

palmately lobed - lobes are arranged as a hand (palm)
pinnately lobed - lobes are arranged in a line
toothed - not lobed, edge is not smooth

See sites above for descriptions and pictures of local trees

Know by sight the following tree leaves:

Maple
Oak
Elm
Tulip
Red Bud
Ash