|Whitethorn Acacia (Acacia constricta)|
DESCRIPTION: Large shrub or small tree up to 10 ft high. Bark reddish-maroon (making it fairly easy to pick out even at a distance) to gray. Leaves are bipinnately compound. Spines long, straight, and white (on new growth) or absent (on old branches). Flowers bright yellow, forming into 0.5" fuzzballs that bloom in late spring and often again in late summer following the monsoon rains. Fruit is a reddish-brown pod. Fabaceae (Legume)Family.
NATURAL HISTORY: Although spines help deter herbivores, they are expensive (in materials) to produce. Therefore, unless older plants are being grazed (or pruned), they often will not have thorns. Without thorns, use the leaves (small, bipinnately compound leaves) and bark color (maroon) to identify. Interestingly, the fragrant, bright yellow flowers offer no nectar and little pollen, thus are not visited as much as Catclaw Acacia that does offer nectar and pollen.