Heliotropium indicum is an annual herb that can reach 1m tall. The stem is slender, woody, and deeply grooved at the base, with a hairy texture.

It is recognized by its rough-textured ovate to oblong-ovate leaves and fragrant lilac flowers arranged in coiled clusters.

Heliotropium Indicum Classification

Domain: Eukaryota
Kingdom: Plantae
Phylum: Spermatophyta
Subphylum: Angiospermae
Class: Dicotyledonae
Order: Boraginales
Family: Boraginaceae
Genus: Heliotropium
Species: Heliotropium indicum
Varieties: Heliotropium indicum var. indicum, Heliotropium indicum var. amplexicaule
Common Names: Indian turnsole, Blue heliotrope, Common heliotrope, Wild heliotrope, Devil weed, and Scorpion weed.

Nativity and Distribution

Heliotropium indicum is believed to be a native plant from Tropical Asia or parts of the United States. It is now naturalized in several regions globally such as:

Africa
Caribbean
Central America
Australia

Physical Characteristics

*Indian heliotrope has rough-textured leaves and small white to purple flowers. Image: Flickr/photographybysha*

Leaves: Ovate to oblong-ovate, alternate dark green leaves.
Fruits: Small brown nutlets.
Stems: Erect, hairy stem stem about 1m in height.
Flowers: Small fragrant white to purple flowers.
Roots: Strong taproot system.

Heliotropium indicum is an erect-growing succulent annual herb that can grow up to 1m tall. It is easily recognizable by its dark green rough-textured leaves and tubular-shaped white to purple flowers arranged in coiled clusters.

The stem is erect, hollow, and deeply grooved with coarse hairs. The leaves are alternate, ovate to oblong-ovate, about 2-10 cm wide and 3-15 cm long, hairy on both surfaces, and dark green in color. The upper surface of the leaves is rough to the touch while the lower surface is prominently veined.

Indian Heliotrope produces small, lanceolate, white to purple flowers about 3-4 mm wide and 2-3 cm long. The tubular flowers are arranged in dense clusters that roll into a spiral pattern at the tip.

The seeds are small, about 2-3 mm wide, round, and dark brown to black in color.

Reproduction, Dispersal, and Life Cycle

Life Cycle: Annual
Seeds: Can produce up to 2,500 seeds.
Climate: Tropical and subtropical climates.
Dispersal: Wind, water, and animals.

Heliotropium indicum behaves as an annual plant and reproduces through seeds. A single plant can produce up to 2,500 seeds in one growing season, many of which are generally viable.

The seeds that fall on the ground surface germinate easily. Indian Heliotrope seeds can also germinate and thrive in partially wet or flooded soils.

The seeds are small, hairy, and lightweight, allowing for wide dispersal by wind, water, and animals to new sites.

However, they can also be dispersed through agricultural and maintenance activities and as a contaminant in agricultural produce.

Similar Plants

Heliotropium elongatum
Heliotropium arborescens
Heliotropium angiospermum
Heliotropium europaeum
Heliotropium ovalifolium

Uses

It is used as an ornamental plant in landscaping.
The leaf extract is used as traditional medicine for healing wounds, conjunctivitis, and skin ulcers.
It is used as a trap plant to control flea beetles in vegetable and cereal farms in India.
In Ghana and Nigeria, it is used to treat jaundice, stings, gumboils, and poisonous bites.
The leaf paste is used to control rheumatism in India.

Impact on Farm and Environment

*Indian heliotrope is a problem weed in crop farms, arid, and riparian habitats. Image: Flickr/ahmadfbm*

Heliotropium indicum is a major farmland weed. It has been observed in sugarcane, maize, and rice fields in many countries including, India, Bangladesh, Venezuela, and Tanzania.

Indian heliotrope contains pyrrolizidine alkaloids that can harm cattle if ingested and will cause symptoms like weakness, nausea, liver damage, or even death.

It is also considered an invasive weed that grows rapidly and can outcompete vegetation in diverse environments, affecting native biodiversity.

Control

Mechanical control: Hand pulling, digging
Chemical control: Dichlormate, Methabenzthiazuron, 2,4-D, MCPA, and Dicamba

Repeated hand pulling and digging can help control small infestations and successive regrowth.

Pre-emergent herbicides like dichlormate and methabenzthiazuron have been shown to prevent weed growth in wheat farms.