Landscape March 2014 L-33

Expanding Tree Diversity in Hawai‘i’s Landscapes: Lignum Vitae, Guaiacum officinale

Richard Criley Department of Tropical Plant and Soil Sciences

low-growing and evergreen, with a rounded crown and beautifully mottled bark, lignum vitae is under- utilizedS in Hawai‘i landscapes because of its slow growth rate. Branching can be irregular, so careful pruning is required to develop a tree form. Typically about 15 feet tall and wide, mature trees can reach 35 feet with a spread of about 25–30 feet. The wood is very hard and very heavy.

Recommended Use in Landscapes • Courtyard • Park • Coastal areas • Specimen tree • Street tree

Distribution • Tropical Americas, Caribbean islands • Dry and humid coastal woodlands • National tree of Jamaica

Propagation Techniques • Seed

Cultural Requirements and Tolerance • Tolerant to diverse soil types • Drought resistant once established • Good degree of salt tolerance • Full sun

Published by the College of Tropical Agriculture and Human Resources (CTAHR) and issued in furtherance of Cooperative Extension work, Acts of May 8 and June 30, 1914, in co- operation with the U.S. Department of Agriculture, under the Director/Dean, Cooperative Extension Service/CTAHR, University of Hawai‘i at Mānoa, Honolulu, Hawai‘i 96822. Copyright 2011, University of Hawai‘i. For reproduction and use permission, contact the CTAHR Office of Communication Services, [email protected], 808-956-7036. The university is an equal opportunity/affirmative action institution providing programs and services to the people of Hawai‘i without regard to race, sex, gender identity and expression, age, religion, color, national origin, ancestry, disability, marital status, arrest and court record, sexual orientation, or status as a covered veteran. Find CTAHR publications at www.ctahr.hawaii.edu/freepubs. UH–CTAHR Expanding Tree Diversity in Hawai‘i’s Landscapes: Lignum Vitae L-33 — Mar. 2014

Flower and Fruit Characteristics • Five-petaled light blue flowers (¾ inch) develop after good rainfall. • Fruit capsule about ¾ inch long, yellow at maturity • Fruits split open to reveal seed with red aril.

Leaf Characteristics • Six broadly elliptical, leathery leaflets pinnately arranged on golden petiole; leaf about 9 inches • Evergreen

Advantages for Use in Landscapes • Adaptable to many uses • Compact • Can be used under power lines • No major pest or disease problems

Disadvantages for Use in Landscapes • Capable of producing many seedlings • Slow growing

2