Plietesials are plants that grow for a number of years, flower gregariously (synchronously), set seed and then die.The length of the cycle can vary between 8 and 16 years. For example, the neelakurinji plant (family Acanthaceae) flowers every 12 years and bloomed as expected in 2006 and 2018 in the Munnar region of Kerala, India.
Other commonly used expressions or terms describing a plietesial life history include gregarious flowering, mast seeding, and supra-annual synchronized semelparity (semelparity = monocarpy).
Certain species of unrelated families of flowering plants Arecaceae, Scrophulariaceae, Fabaceae, Apocynaceae, and Acanthaceae are plietesial. This type of life history is especially well known among certain bamboos (family Poaceae) some of which have a life cycle of 40 to 50 years.
It is not clear why gregarious flowering after long vegetative intervals would be associated with death after flowering, although both are associated with higher reproductive outputs.[1]