Kiawe trees (Prosopis pallida) are native to the northeastern corner of South America. They were introduced to Hawaii way back in 1828 and now are the dominant tree in coastal areas on the drier west side of this island. The downside of this is that the tree has wicked thorns that penetrate tires and footwear. My feet have been jabbed through Teva sandals and Adidas hiking shoes. The most popular footwear in Hawaii are slippahs (flip-flops or thongs), but one has to be brave and vigilant, or maybe foolish, to wear those where kiawe grow.
On the plus side, the tree’s wood is popular for firewood and barbecues. Kiawes also provide shade and have light yellow flowers which are popular with bees and butterflies such as the painted lady butterfly in this photo.