Yep, 2nd in the search...
Lignumvitae - also known as guayacan, palo santo, and ironwood. Scientific name: Guaiacum sanctum (GWY-uh-kum SANK-tum)
Family: Zygophyllaceae
Lignumvitae is an extremely slow-growing broadleaf evergreen, not native to North America, which ultimately reaches 30 to 40 feet in height and casts light shade, but few people have seen plants of this size because it is not grown in the trade. Most are seen 8 to 12 feet tall with a beautiful array of multiple trunks and a rounded canopy much like that of a mature Crape-Myrtle. The one to two-inch-long, leathery, dark green leaves are joined at many times throughout the year by the production of large clusters of deep blue flowers, the old flowers fading to a light silvery-blue and creating a shimmering haze over the rounded canopy. These flowers are followed by small, heart-shaped, yellow berries, appearing on the tree at the same time as the blue flowers and creating a lovely sight.
Underneath the smooth, beige/grey bark of Lignumvitae is some of the heaviest of all wood, sinking under its weight instead of floating in water. This dense wood was once popular for use in the manufacture of bowling balls and has also been used for propeller shafts on steamships, gears and for mallets.
This wood, known among carvers as "lignum", is known to be the heaviest and most dense wood in the world.