Guajacum sanctum
Common Name: lignum vitae 
Type: Broadleaf evergreen
Family: Zygophyllaceae
Native Range: Florida, Mexico, Caribbean, Central America
Zone: 10 to 11
Height: 9.00 to 12.00 feet
Spread: 9.00 to 12.00 feet
Bloom Time: Seasonal bloomer
Bloom Description: Blue
Sun: Full sun to part shade
Water: Medium
Maintenance: Low
Suggested Use: Flowering Tree
Flower: Showy
Leaf: Evergreen
Other: Winter Interest
Tolerate: Drought

Culture

Winter hardy to USDA Zones 10-11. Full sun to part shade. Moderate but consistent water. Good drought tolerance. Requires sharply well-drained soils. Tolerates wind. Tolerates salt spray.

Noteworthy Characteristics

Guaiacum sanctum, commonly called lignum vitae (wood of life) or palo santo (holy wood), is a slow-growing, multi-stemmed, broadleaf evergreen tree or shrub that is native primarily to dry coastal areas in the Florida Keys, Bahamas, West Indies, Central American and northern South America. It will grow over time to as much as 35' tall with a dense rounded canopy, but is most often seen in the 9-12' range. Ornamental features include shiny compound evergreen leaves, brown bark with gray patches, blue flowers and ornamentally attractive seed pods. The wood of trees in this genus is resinous, dense, heavy and very hard. It is considered to be the hardest wood ever commercially used. It is almost impossible to drive a nail into the wood. Wood will sink rather than float in water. Wood was once used for making propeller shafts for steamships, bearings, gears and mallets. Pinnate compound dark green leaves (3-5 pairs of ovate leaflets - each leaflet to 2" long) are evergreen. Star-shaped, 5-petaled, blue flowers (1" diameter) in terminal clusters bloom on and off throughout the year, but most frequently in early spring (March-April). Fruits from the spring flowers ripen in summer. Fruit is a dehiscent orange capsule that splits open when ripe to reveal one or two black seeds each covered with a fleshy bright red aril. Dark brown bark on mature trees peels to show patches of gray. Resins in the wood have been medicinally used in the past to treat a variety of ailments (e.g., arthritis, gout, rheumatism), hence the aforementioned common names which refer to the plants live-sustaining properties. Guaiacum sanctum is listed as endangered on the International Union for Conservation of Nature's RED LIST of Threatened Species and in Appendix II of CITES. Threatened status is primarily due to habitat loss and human exploitation. Species is the National tree of the Bahamas. Tree flower is the national flower of Jamaica.

Genus name comes from the South American vernacular word guaiac the name for lignum vitae (G. officinale), meaning wood of life, so named because of its high repute in medicine.

Specific epithet means holy.

Problems

No serious insect or disease problems.

Garden Uses

Where winter hardy, it grows well in coastal plantings. Also serves as an attractive ornamental lawn tree. It also can be grown as a shrub. May be grown in containers due to slow growth rate.