Maple Trees with simple leaves, small 5-part green flowers in clusters and paired keys.
Pine Mostly evergreen needle and cone bearing trees. Seeds are winged.
Olive Ashes have compound leaves, male and female flowers on different trees and clusters of keys.
Elm Trees with simple leaves with an asymmetric base, clusters of small flowers along the twigs, and seeds surrounded by papery wings.
Quassia Tree of heaven is a small tree with large pinnately compound leaves, branched clusters of small flowers and dense clusters of reddish keys.