They are large shrubs or small trees growing to 5–12 m (16–39 ft) tall, dry seasondeciduous, with sparse, open, thorny crowns and green bark. The leaves are pinnate, usually bipinnate, with numerous small leaflets; they are only borne for a relatively short time after rains, with much of the photosynthesis carried out by the green twigs and branches. The flowers are symmetrical or nearly so, with five yellow or white petals. The fruit is a pod containing several seeds.
Most American species are known by the common name of palo verde or paloverde, derived from the Spanish words meaning "green tree". This name is given due to its characteristic green trunk. The palo verde (not species-specific) is the state tree of Arizona.[5]
Ecology
A major pollinator for Parkinsonia species in the southwestern United States and western Mexico is Centris pallida, a solitary bee known as the digger or pallid bee. C. pallida obtains nectar and pollen from this plant to fill a brood pot so that their larvae will have food when they hatch. The nectar and pollen give its bee bread a strong orange color.[6]
