Also called Soapbush. It's of the Zygophyllaceae family and one of the most fascinating plants I've seen. Would love to have one! Guaiacum angustifolium is the botanical name. It's a perennial evergreen bush, a bit odd-looking. Grows in the southern part of the Edwards Plateau, South Texas, Trans-Pecos into northern Mexico. Leaves are little pinnately compound clustered leaflets that remind me of some legume leaves. Flowers are violet to purple petals around off-white centers and stamens have yellowish anthers. The fruits turn red and in fall the plant has the red and green which reminds me of a really unusual Christmas tree.
I still don't have a pic of the plant with those bright red fruits! It just about broke my heart when a section of land above a creek in San Antonio was developed. There were Guayacan and many other great plants there. They didn't manage to destroy all the Guayacan, fortunately.