Guaiacum sanctum

Guaiacum sanctum, commonly known as holywood or holywood lignum-vitae, is a species of flowering plant in the creosote bush family, Zygophyllaceae. It ranges from India, Sri Lanka, Java and the Tivu islets of the Indian ocean, southern Florida in the United States and the Bahamas south to Central America and the Greater Antilles. It is threatened by habitat loss. Guaiacum sanctum is the national tree of the Bahamas. This small tree is slow growing, reaching about 7 m (23 ft) in height with a trunk diameter of 50 cm (20 in). The tree is essentially evergreen throughout most of its native range. It is shade tolerant. It fruits between the age for 30 and 70 years over the summer months in the Northern Hemisphere. The wood is hard, heavy and self-lubricating and has a Janka Hardness Score of 4500, which is one of the hardest in the world. It can sink when placed in water. There are fine ripple marks on the wood. The leaves are compound, 2.5–3 cm (0.98–1.18 in) in length, and 2 cm (0.79 in) wide. They are dark green in color and occur as three to five pairs of leaflets. They fold together during the hottest parts of the day. The purplish blue flowers have five petals each. They can grow individually or in clusters at the ends of branches. The flowers have both male and female parts (stamens and pistils) and yield yellow pods containing black seeds encapsulated separately in a red skin. This tree is one of two species which yield the valuable Lignum vitae wood, the other being Guaiacum officinale. The wood has been used for making specific parts of ships that needed to be self-lubricating so that they would last longer.