Erythrina crista-galli lower branches

The bark of Erythrina crista-galli is grey-brown and deeply, longitudinally fissured or furrowed. The somewhat crooked branches curve variably, becoming gnarled with age. The tree has a taproot, the roots bearing nodules of nitrogen fixed by bacteria. Most legumes form a symbiotic relationship with nitrogen-fixing bacteria called rhizobia.

The trifoliolate leaves have spines along the leaflet veins and on the long petioles. The young, upper branches are spiny, sometimes dying back seasonally (Wikipedia; iNaturalist; www.smgrowers.com).