Cymbopogon martinii, commonly known as palmarosa, Indian geranium, or rosha grass, is a tall, perennial, tufted grass in the Poaceae family. The plant typically grows between 1.3 and 3 meters in height, with erect, slender stems arising from a stout, woody rootstock. Its linear-lanceolate leaves are pale green, sword-shaped, and can reach up to 50 cm in length and 1–3 cm in width, emitting a sweet, rose-like fragrance due to the high geraniol content in its essential oil. The inflorescence is a narrow, erect panicle up to 30 cm long, with small, inconspicuous flowers that appear in autumn.
The plant is valued for its aromatic essential oil, which is colorless to pale yellow and widely used in perfumery, cosmetics, and aromatherapy. The oil is extracted from the above-ground parts of the plant, especially when harvested in full bloom, and is known for its antifungal, insect-repellent, and medicinal properties.
Habitat
Cymbopogon martinii is native to the Indian subcontinent and Indochina but is widely cultivated in tropical and subtropical regions around the world. It thrives in open grasslands, plains, and the edges of deciduous forests, often found in well-drained, sandy or loamy soils. The species is drought-tolerant, prefers full sun, and is intolerant of waterlogged conditions, making it well-suited to areas with moderate rainfall and warm temperatures.
Planting and Care
- Light: Prefers full sun for optimal growth and oil production.
- Soil: Requires well-drained, sandy or loamy soils; intolerant of waterlogged or slow-draining soils.
- Watering: Moderate drought tolerance; regular watering is needed during establishment, but mature plants require less frequent irrigation.
- Fertilization: Benefits from soils with adequate nitrogen, phosphorus, and potassium; adjust fertilization based on local soil conditions.
- Harvesting: Harvest above-ground parts when the plant is in full bloom for highest oil yield; typically one harvest in the first year, increasing to two or three in subsequent years.
- Maintenance: Remove old or declining clumps after 4–8 years as oil yield decreases with plant age; propagation is usually by division of clumps.
Additional Information
- Ornamental Use: Sometimes grown for its tall, graceful appearance and aromatic foliage.
- Medicinal Properties: Used in Ayurveda for treating joint pain, respiratory diseases, anorexia, intestinal worms, skin diseases, and diarrhea.
- Essential Oil Uses: Palmarosa oil is prized in perfumery, soaps, and cosmetics for its rose-like scent; also used as an antifungal, insect repellent, and in aromatherapy.
- Agricultural Benefits: Palmarosa oil can protect stored grains and beans from insects and fungi.
- Varieties: Two main cultivated types-Motia and Sofia-differ in oil content and growth habit.
- Economic Importance: Widely cultivated and exported for its essential oil, contributing to rural economies in India and other tropical countries.
