Plants that bloom at long intervals like The Neelakurinji, S trobilanthes kunthianus, are known as Plietesials - the plants that grow for a number of years, flower synchronously, set seed and then die. The length of this cycle can vary between 8 and 16 years.
The Neelakurinji is a blue-and-lilac beauty with a 12-year life cycle. It flowers only once in its lifetime, and once it does, the plant dies. The seeds from the dying plant go back into the ground and lay dormant for almost a dozen years. Eventually, they sprout, grow, bloom for a magical two-month period and die again, restarting the cycle.
In India, the Neelakurinji flowers bloom in the 'Nilgiri Hills', which literally means the 'blue mountains'. These hills got their name from the purplish-blue flowers of Neelakurinji. These flowers also bloom in the region of Palani Hills and the Anaimalai Hills. Eravikulam National Park (UNESCO World Heritage Site) and Kurinjimala Sanctuary in Munnar, Kerala have the largest area dedicated to conserve these shrubs.
Kurinji plants grow at an altitude of 1300 to 2400 metres. The plant is usually 30 to 60 cm high. One can view the shorter variation of about 2 feet at higher spots and longer variations of about 5 to 10 feet at lower spots. When the kurinji bush blooms, it has a profuse display of violet-blue flowers that cover the entire plant and these blossoms spread out as a blanket on the hill slopes making it look like a purple blanket over the green hills.