Ecological studies were carried out on 19 endangered populations of Meconopsis horridula, M. paniculata, M. simplicifolia, M. sinuata and M. villosa from the Sikkim Himalayas. The populations of M. horridula, M. paniculata and M. sinuata inhabit open alpine slopes, those of M. simplicifolia are restricted to alpine meadows, while those of M. villosa are confined to the interiors of temperate forests and along forest fringes. The habitats of these species remain snow-hound from October to February. Analyses suggest that all the species except M. horridula, have a broad area of distribution, but narrow habitats and niches. All five species are confined to moist, clayey to silty soils with acidic pH, high concentrations of organic matter, nitrate, phosphate, potassium and calcium. M. paniculata is a ‘generalist’, whereas all other species investigated are ‘specialists’.