Foliage is deciduous, opposite, pinnately compound, 4-10" long, with (3)5-7 leaflets, each leaflet elliptical to lanceolate, 1-2" long, terminal leaflet larger than the others, with long petiolules (petioles of the leaflets), margins lightly serrated along the upper half of the leaflet, entire on the lower half or more. Upper surface medium green, lower may be pubescent, especially in the spring, or smooth later in the summer. Terminal leaflet is very wide in the middle of the leaf, narrowing to a long point, while the others are much narrower.
Not sure it makes much of a difference but the rachis and the petiolules are very much grooved.
Trees are males. Don't have any pictures.
No fruit as they don't have female flowers.
Stems are pubescent when young, smooth later in summer, brown with white lenticels. Terminal buds with dense copper colored hairs and clustered in 3's, with the center one much larger than the others. Prominent leaf scars strongly U shaped with the bud in the center of the U. Not as strongly U shaped as F. americana.
Bark is smooth and gray when young, turning rough and scaly with age.
Misidentification:
Lots of ash trees look alike, this one has different terminal leaflets, often only 5 leaflets, holds its fall color longer than most. Around here you will see mostly Green Ash and the Evergreen Ash. If you are really unsure, wait till fall and into winter. The green ash has the bud on top of the leaf scar, and the evergreen ash is…. evergreen.
Location:
Aptos
3070 W. Ledyard Way
Santa Cruz
1003 Morrissey Blvd on the corner with Park Way.