Parkinsonia aculeata (Mexican Palo Verde) - Dry garden landscaping. 'Desert Museum' is the most prized hybrid mostly for its lack of thorns. This tree is extremely fast growing when regularly irrigated, reaching 20' x 20'. Once established it takes very little water. It can exist on rain water alone, but will grow much slower. Evergreen though leaves are quite small. Beautiful display of flowers in spring. Casts light shade.