Sri Andhaka Nivarani Ambaal (Sri Irul Neekki Ambaal) Sameda Sri Oushadheeswarar (Marundheeswarar) Temple , Tirukacchur, Chennai
Lord Indra had a rare disease which cannot cured by his doctors - the Aswini Devas. The Ashwini devas then came to Tirukacchur to find some rare herbs and worshipped Lord Shiva here. They were unable to find the right herb that could cure Indira's ailment
Ashwini devas did penance here for twelve years and during the course of time they found that the plants, flowers and shrubs look the same in all seasons. They wondered how this can happen. Lord Shiva, doesn't want to test the patience of Aswini Devas and gave darshan there and told them that the soil of this Place itself is medicine. Hence marundeeshwar temple has a small place where one can collect the Soil and apply on Fore Head and drink with water
It is also said that Sage Agasthiyar worshipped Lord Marundheeswarar both at Thiruvaanmiyur and Thirukkachur and enriched his knowledge on Herbal Medicines
See also http://www.dharsanam.com/2008/03/thirukkachur-sri-oushadheeswarar.html