Question 1

What is Pistia stratiotes used for in Ayurveda?

Accepted Answer

In Sri Lankan and broader South Asian Ayurvedic practice, Pistia stratiotes is used to address skin inflammations, haemorrhoids, urinary complaints, and fever. It is classified as a cooling herb and applied both topically as a paste and internally as a decoction. Its use should always be guided by a qualified practitioner.

Question 2

What is the Sinhala name for Pistia stratiotes?

Accepted Answer

Pistia stratiotes is known in Sinhala as 'Geta Kesel' or 'Jappu' in some regional dialects, though local names can vary across districts. In Sanskrit Ayurvedic texts it is referred to as Jalakumbhi, meaning 'water pot plant', a reference to the rounded shape of its leaf rosette.

Question 3

Is Pistia stratiotes native to Sri Lanka?

Accepted Answer

The plant is considered pantropical in distribution, meaning it occurs naturally across tropical regions of Africa, Asia, and the Americas. In Sri Lanka it is well established and abundant in freshwater wetlands, tanks, and slow rivers, and is regarded as part of the native or long-naturalised aquatic flora.

Question 4

Is water lettuce (Pistia stratiotes) safe to eat?

Accepted Answer

Pistia stratiotes is not generally consumed as a food plant. While some sources note limited traditional food uses in certain African communities, in Sri Lanka it is treated strictly as a medicinal herb. Internal preparations should only be taken under professional Ayurvedic supervision, and raw consumption is not recommended.

Question 5

Can Pistia stratiotes be used to clean polluted water?

Accepted Answer

Yes, the plant has documented phytoremediation potential. Its extensive root system absorbs nitrogen, phosphorus, and some heavy metals from polluted water, making it useful in constructed wetland systems designed to treat agricultural run-off or wastewater. However, plants grown in polluted water should never be harvested for medicinal use.

Question 6

Where can I see Pistia stratiotes growing naturally in Sri Lanka?

Accepted Answer

The plant is common in slow-moving rivers, lagoons, and irrigation tanks across the island. It is frequently seen on boat excursions through coastal wetland systems, in the margins of ancient tanks in the dry zone, and alongside paddy-field drainage channels. River and lagoon boat tours in the south-west coastal belt often pass through areas where it grows.

Question 7

How does Pistia stratiotes fit into Sri Lanka's broader Ayurvedic tradition?

Accepted Answer

Sri Lanka maintains one of the world's living Ayurvedic traditions, with government-registered practitioners, Ayurvedic hospitals, and a formal catalog of indigenous medicinal plants that includes Pistia stratiotes. The plant is one of many aquatic and wetland species documented in this system, sitting alongside better-known herbs to form a rich pharmacopoeia rooted in centuries of clinical observation.