Yellow Bird Of Paradise. Caesalpinia gilliesii, Pea Family: ( Fabaceae ), Yellow Bird of Paradise. Also Called: Mexican Bird of Paradise. We wish to thank Wikipedia, the free encyclopedia for some of the information on this page. We share images and information with Wikipedia. A large irregular shrub which can be trained to become a small deciduous tree. It may become an evergreen in warmer areas. Attracts hummingbirds. Quick Notes: Height: Up To 5 - 10 feet tall, they spread out 4 -6 feet wide. Stems/Trunks: Greenish stems, noticeable lenticils, spineless; a slender trunk if any. Fruit: Tan fuzzy pod, dehiscent, curled, persistent on branches unless removed. Flowers: The flowers are on branch terminals, informal racine of solid yellow flowers with long red stamens; they bloom mainly in the spring and early summer, then sporadically; 4 - 5 inches long. Flowering Time: March - September. Leaves: Bipinnately compound leaf. With 6 to 12 pairs of pinnae and 5 to 10 pairs of leaflets. Found: The USDA claims Caesalpinia gilliesii is native of the USA (AZ, CA, GA, NM, NV, OK, TX, UT), USA+ (PR). In Arizona it is native of all counties except La Paz, Yuma, Navajo, Apache, & Greenlee counties. It is also natiuralized in many parts of Mexico & Australia. It is native of many parts of South America. Peru, Argentina, Chile; & Uruguay. Hardiness: USDA Zone 8b: to -9.4 �C (15 �F) USDA Zone 9a: to -6.6 �C (20 �F) USDA Zone 9b: to -3.8 �C (25 �F) USDA Zone 10a: to -1.1 �C (30 �F) USDA Zone 10b: to 1.7 �C (35 �F) Soil pH requirements: 6.6 to 7.5 (neutral) 7.6 to 7.8 (mildly alkaline) 7.9 to 8.5 (alkaline) Sun Exposure: Full Sun Elevation: 0 Feet - 5,000 Feet. Habitat: Alkaline, Chalky/alkaline, Dry, Sandy, Well-drained/light soils, sandy washes. An ideal xeriscape landscape plant in Arizona. Miscellaneous: Flowering Photos Taken June 13, 2003. Hawkins Ranch, Near Date Creek, Arizona.