Today's photograph is shared by Peter Buchwald (original image | Creative Commons License). Lindsay continues with January's thematic series on conservation of rare plants as part of the International Year of Biodiversity. Lindsay writes:

Commonly known as lignum vitae ("wood of life") or holywood, Guaiacum sanctum is native to the Florida Keys of the southeast USA, Central America and the Caribbean. It is the national flower of the Jamaica. Lignum vitae is an extremely slow-growing, multi-trunked, broadleaf evergreen which can reach 9m to 12m, but because of its slow growth and heavy harvesting, it is more commonly found at 2.5m to 3.5m tall in the wild.

A number of times each year, the leathery, dark green leaves are offset by large clusters of deep blue flowers. The old flowers fade to a light silvery-blue, and create a "shimmering halo" over the rounded canopy. Flowers are followed by small, heart-shaped, yellow fruits, which sometimes appear at the same time as the blue flowers--a stunning sight. The wood of this genus is famous for its density, durability and strength. It is the hardest trade wood measured via the Janka hardness test and will sink in water. This dense wood was once popular for use in propeller shafts on steamships, gears and mallets.Lignum vitae was also harvested, somewhat notoriously, for medicinal purposes. Purportedly, during his travels in the New World, Christopher Columbus picked up both syphilis and its cure--a concoction of lignum vitae!

All species of the genus Guaiacum are now listed in Appendix II of the Convention on International Trade in Endangered Species of Wild Fauna and Flora. According to the World Conservation Monitoring Centre, Guaiacum sanctum is considered endangered. It is similarly listed on the International Union for Conservation of Nature's Red List of Threatened Species. Population estimates suggest less than 2500 mature specimens in the wild, and those remaining individuals still face a rapid decline. Decline is principally due to deforestation and exploitation for human uses. In Central America and Florida remaining populations are threatened with habitat loss or exploitation, e.g., in Guancaste in Costa Rica, El Salvador, and Florida Keys. Conservation groups in both Costa Rica and the Bahamas have been successful in lobbying local authorities to ban sale and export of lignum vitae by establishing protected areas in its natural range. Despite its slow growth rate, propagation of Guaiacum sanctumis fairly easy. Current research suggests its use in rehabilitating degraded sites within its natural range.