Abstract
This paper describes seven new Gomphonema species from the Himalaya and provides information about their ecology with respect to water chemistry and habitat character. Diatoms were collected during surveys of over 200 Himalayan streams between 1993 and 2000. The geographical distribution, which covers a 1000 km east-west range in the Himalaya of north-west India and Nepal, is discussed along with the occurrences of these taxa in relation to environmental conditions.