Question 1

What is Imperata cylindrica used for in Ayurveda?

Accepted Answer

In Ayurvedic medicine, Imperata cylindrica root and rhizome are used primarily as a diuretic, a cooling agent in fevers and inflammatory conditions, and a haemostatic herb. Decoctions of the dried root are among the most common preparations. The plant is classified as having cooling properties and is included in formulations targeting urinary and renal health.

Question 2

What is the Sinhala name for Imperata cylindrica?

Accepted Answer

The Sinhala name for Imperata cylindrica is Illuk (ඉල්ලුක්). It is also widely known in English as cogon grass or blady grass. In Sanskrit Ayurvedic literature it is often referred to as Darbha or Kasha, though these names have sometimes been applied to related grass species as well.

Question 3

Where does cogon grass grow in Sri Lanka?

Accepted Answer

Cogon grass grows widely across Sri Lanka's dry, intermediate, and low-elevation wet zones. It is common in open scrubland, along roadsides, in degraded forest margins, and in national park grasslands. It tolerates poor, sandy, and laterite soils, making it one of the most adaptable and widespread grasses on the island.

Question 4

Is Imperata cylindrica the same plant as kusha grass?

Accepted Answer

Imperata cylindrica is often equated with the Sanskrit term Darbha or Kasha used in Ayurvedic texts, but taxonomists note that classical names have sometimes been applied loosely to related grass species. The botanical identification of Imperata cylindrica with specific classical Sanskrit grass names varies across scholarly sources, so it is important to rely on scientific nomenclature when sourcing the plant for medicinal use.

Question 5

Which part of Imperata cylindrica is used in traditional medicine?

Accepted Answer

The rhizome (underground stem) and roots are the parts most commonly used in Ayurvedic and traditional Sri Lankan medicine. The above-ground leaves and stems have fewer documented medicinal applications, though the ash of the plant has occasionally been used in topical preparations for wound care.

Question 6

Is cogon grass considered invasive in Sri Lanka?

Accepted Answer

Imperata cylindrica is considered problematic in agricultural contexts across Sri Lanka because its vigorous rhizome system regenerates rapidly after cutting or burning, making it difficult to eradicate from cultivated land. In semi-natural grasslands and protected areas, however, it functions as a native component of the ecosystem rather than a disruptive invasive species.

Question 7

Can I see Imperata cylindrica in Sri Lanka's national parks?

Accepted Answer

Yes. Open grassland patches within dry-zone national parks such as Udawalawe and Wilpattu contain extensive stands of Imperata cylindrica. These grassland areas are important for wildlife, supporting browsing by elephants, deer, and other herbivores. The feathery white seed heads of the grass are particularly visible during and after the dry season.