Study discusses climatic factor’s impact on flowering of exclusively endemic Impatiens johnii Barnes, I. coelotropis C. E. C. Fischer and I. platyadena C. E. C. Fischer. Mean noon temperature ranged from 190 C - 19.50 C revealing no influence on flowering. But survival is only in temperature range around 190 C. Peak Relative Humidity from July to September persuades I. johnii to initiate flowering. At higher RH flowering plants were more except in I johnii which flowers from September to December. Vegetative resurrection happened in all species by onset of monsoon. In I johnii, a facultative lithophyte vegetative enlargement took 3 months for flowering. Rainfall triggers spontaneous and staggered flowering in other two as and when it rains. Even at lower rainfall higher RH favors optimum flowering ascribed to stored biomass of previous year’s growth. There is direct relationship of luxurious flowering and high rainfalls. Low rains reduce seed production and number of new individuals for coming year.
