17 Jul The tree with yellow flowers: Gold medallion trees light up the streets of Southern California

“Gold medallion […] blooms well near the ocean, but benefits from reflected heat of nearby pavement,” writes The Sunset Western Garden Book, explaining why the tree with yellow flowers in California — Cassia leptophylla — is doing gangbusters right now in the beachy yet highly developed neighborhood of Bird Rock. To ride your bike down La Jolla Boulevard — past Beaumont’s restaurant and bar, Bird Rock Coffee, the local Masonic Lodge — is to cruise down a street paved in gold. Meet the gold medallion tree.

Every summer, the main strip of the Bird Rock neighborhood of La Jolla is irradiated with gold medallion trees.

Each brilliant yellow flower is about three inches wide, and blooms in ring- and orb-shaped clusters. The drought-tolerant tree thrives in full sun.

The signal-yellow flowers alone aren’t what make this summer bloomer such an arresting street tree. It’s how the flowers of the gold medallion, a legume family member, are clustered: in melon-size orbs containing dozens of blooms. In the vertical light of day, the clusters suggest the flat, unresolved yellow hoops you might find in a work of abstract impressionism. Around sunset, these babies glow like fragrant balls of lightning you can hold in your hand.

According to Pacific Horticulture, the plant is native to Brazil, and can reach up to 25 feet in height and 30 feet in width. Semievergreen, they do drop some leaves in winter in cooler climates.

Outside our favorite coffee shop: Cassia leptophylla will develop multiple trunks if not pruned early to a single trunk.

The seed pods extend to over a foot long.

Flowers give way to seedpods, one of which we picked up yesterday off the street. It was dark maroon, 16 inches long, and rattled festively. We cracked it open (with extreme difficulty; RB gave up on knives and had to twist it with all his strength) to find pale tablet-shaped seeds inside. Despite these conspicuous pods and its ubiquity (we spotted many in bloom in Los Angeles last weekend on Lincoln Boulevard), Cassia leptophylla has managed to remain a crowd favorite — thanks to its elegant canopies, drought tolerance and friendliness to full sun.

—TH

Cassia leptophylla’s lush, graceful silhouette makes it a favorite street tree. Extra points if you can spot our intrepid photographer in this shot!