Plant: Shrub or tree to 4 m, armed with curved spines Leaves: leaves alternate, twice compound with 2-4 pinnae Flowers: flowers cream in dense elongate clusters Fruit: a pod with round segments irregularly constricted. Misc: Flats, washes; 100-1400 m.; Apr-Jun References: Shreve, F. and I. Wiggins. 1964. Vegetation and Flora of the Sonoran Desert. Standford University Press. Stanford Cal.J.C. Hickman, ed. The Jepson Manual.