Overview
Trichodesma zeylanicum is an erect annual or short-lived perennial herb of the family Boraginaceae, growing 1.5–6.5 feet (0.5–2 m) tall and 1–2 feet (30–60 cm) wide. The whole plant is rough with stiff, bristly hairs. Lance-shaped leaves 2–5 inches (5–13 cm) long are opposite low on the stem and alternate above, with a harsh texture on both surfaces. The nodding flowers are pale blue to almost white, about 0.6–1 inch (15–25 mm) across, with five pointed lobes and a cone of dark anthers twisted into a central beak. Flowering follows the wet season and continues while soil moisture lasts. The fruit breaks into rough, warty nutlets. Trichodesma zeylanicum grows on disturbed ground, roadsides, floodplains, and open woodland across tropical Africa, southern Asia, and northern Australia, often colonising bare soil after rain. It establishes quickly from seed and can spread into cultivated and grazed land. It can contain pyrrolizidine alkaloids that are toxic to livestock if eaten in quantity.
Native Range
Native across tropical Africa, southern Asia, and northern Australia, growing on floodplains, roadsides, and disturbed ground in seasonally wet-and-dry climates.Suggested Uses
Used in native and informal plantings in tropical and subtropical gardens and for quick seasonal cover on bare ground. Suited to low-water and disturbed sites. Spaced 18–36 inches (45–90 cm) apart.How to Identify
Appearance
Size & Dimensions
Height1'6" - 6'6"
Width/Spread1' - 2'
Colors
Bloom Information
Flowering follows the wet season, mainly through the warmer months, and continues while soil moisture remains. The nodding flowers are pale blue to nearly white, 0.6–1 inch (15–25 mm) across, with a central beak of twisted anthers. Rough nutlets ripen as the flowers fade.
Detailed Descriptions
Flower Description
pale blue to white with a dark anther coneFoliage Description
grey-green to greenGrowing Conditions
Sun Requirements
Requires 6-12 hours of direct sunlight daily
• Full Sun: 6+ hours of direct sunlight
• Partial Shade: 3-6 hours of direct sunlight
• Full Shade: Less than 3 hours of direct sunlight
Water & Climate
Water Needs
Drought Tolerance
Drought tolerant when established
Care & Maintenance
Care Guide
Grow Trichodesma zeylanicum in full sun in light, free-draining soil. It needs warmth and seasonal moisture and completes much of its growth during and after the wet season. The plant is drought-deciduous, dying back or setting seed as soils dry. It self-seeds freely and can become weedy on disturbed ground. Frost kills the top growth. It can contain pyrrolizidine alkaloids that are toxic to livestock if eaten in quantity.Pruning
No formal pruning is needed. Spent stems can be cut back after flowering, and self-sown seedlings removed where spread is unwanted. Whole plants can be pulled once they set seed and dry off.⚠️ Toxicity Warning
Toxic to pets and humansPlanting Guide
Planting Methods & Timing
Planting Method
direct sow
Direct Sow Timing
at the onset of the wet season when soil is warm
Days to Maturity
60–120 days
Plant Spacing
24 inches