Sydney Golden Wattle is more likely a large shrub but we will consider it a small tree commonly used as a utility tree along freeways. These evergreen trees grow really fast to 20' x 20' with a rounded habit, dense canopy with branches to the ground. The end result is nondescript evergreen screen. Trees become visible as soon as they bloom. Most commonly seen along the freeway.
Leaves are alternate, evergreen, simple, oblanceolate, thick, bright green, no distinct upper or lower surface, more or less 4" long, sometimes slightly curved. Like all simple Acacia leaves, these are phyllodes or flattened petioles.
Stems are thin, green with small rounded vegetative buds.
Older stems are sort of cool looking, nice color and lines on the stems from the buds.
Flowers in mid winter. Flowers are small, yellow, rounded balls of flowers in elongated clusters, fragrant. Bright yellow.
Fruit is a pod, usually twisted.
Misidentification:
In bloom, not as likely, the flowers are super bright yellow on an elongated inflorescence.
Location:
Most commonly seen on the freeway.
Aptos
Just below the railroad overpass closest to Rio Del Mar Exit
Santa Cruz
Along the highway at the old drive in movies, now the swap meet. (Pulled out for more lanes)