Common Name: tree heliotrope
Type: Broadleaf evergreen
Family: Boraginaceae
Native Range: Polynesia, Micronesia, Indian Ocea
Zone: 12 to 12
Height: 15.00 to 20.00 feet
Spread: 15.00 to 20.00 feet
Bloom Time: Flowers freely
Bloom Description: White
Sun: Full sun
Water: Dry to medium
Maintenance: Low
Suggested Use: Annual, Shade Tree
Leaf: Evergreen
Attracts: Hummingbirds, Butterflies
Tolerate: Drought, Erosion, Shallow-Rocky Soil
Culture
Best grown in sandy or rocky, loose, well-draining, dry to medium moisture soils in full sun. Tolerates poor, shallow soils, drought, heat, and salt spray. Intolerant of compacted, waterlogged soils. This tropical plant is hardy in Zones warmer than 12.
Noteworthy Characteristics
Tournefortia argentea, commonly called tree heliotrope or velvetleaf soldierbush is a large, slow growing, evergreen shrub or small tree native to tropical, sandy, windswept coastal areas of eastern Africa, Madagascar, Sri Lanka, and Oceania. Mature individuals can reach up to 20' tall with a roughly equal spread. It tends to form a spreading, umbrella-shaped canopy. The leaves (up to 12" and 5" wide) are obovate to oblanceolate in shape, held in whorled, terminal clusters, and are covered in dense, silvery hairs. Small, white flowers (1/5-1/4" in diameter) bloom throughout the year on terminal branched cymes. The flowers are attractive to butterflies and other insect pollinators. Small, green fruits encase brown nutlets, which can float and are dispersed by ocean currents.
Tree heliotrope is a significant plant to people of the Pacific Islands, having culinary, medicinal, religious, and crafting uses. It is also an important plant for creating salt spray barriers, wind breaks, and stabilizing coastal soils.
Genus name honors Joseph Pitton de Tournefort (1656-1708), celebrated French botanist.
The specific epithet argentea means silvery, in reference to the appearance of the foliage.
The common name tree heliotrope comes from this plant's former genus Heliotropium.
Problems
Heliotrope moth larvae are a potential pest if planted in the Central to Eastern Indo-Pacific where the moth is found. Otherwise, no major disease or pest concerns. Root rot can occur if planted in wet, poorly-drained, compacted soils.
Uses
Suitable for use as a shade tree in tropical seaside gardens and public areas.