Genus Cladrastis Species kentukea Cultivar Common Name American Yellowwood Patent ID Height 30 to 50 Feet Spread 40 to 50 Feet Habit Medium size, spreading to somewhat rounded tree. Slow to moderate growth rate. Zone 4 to 8 Culture Flower Fragrant white, in long terminal panicles, May-June. Must have some age and size on the tree before it flowers. Flower Color Foliage Compound, dark green in summer and yellow in fall. Deciduous. Category: Shade Tree Description Native tree.