Neelakurinji flowers once in
Neelakurinji Strobilanthes kunthiana or Strobilanthes sessilis exhibits plietesial monocarpy — prolonged vegetative phase 11-12 years accumulating resources, then synchronous gregarious flowering covering entire hillsides in purplish-blue, seed set, and death. Phenomenon observed in high-altitude grasslands of Munnar, Kodaikanal, and Coorg within Western Ghats. Mass flowering satiates seed predators and maximizes pollination efficiency with honeybees. Botanical Survey monitors cycles; last mass bloom 2018 attracted global tourists. Twelve-year interval defines cultural calendar of Western Ghats hills. Clarity on this principle prevents confusion between in-situ and ex-situ methods often interchanged in examination options.
Ref: Botanical Survey India Strobilanthes kunthiana 12-year Bloom; Kerala Forest Neelakurinji Factsheet Munnar