• Source: Plietesials

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.

There is considerable variation in life history for Strobilanthes. Most known plietesial Strobilanthes take between 10 and 15 years (usually 12; although reports of 5 to 9 year cycles also have been made) to flower gregariously, set seed, and die. The flowering periodicity in all individuals is rarely 100%, with the result that flowering of rare individuals in non-mass-flowering years is not uncommon. In some species, mass flowering occurs over a wide area on a species-specific cycle; in other species, populations in different regions follow their own cycles. Some species flower gregariously in certain years but do not die following the mass flowering, and are therefore not plietesial. At least one species exhibits different flowering patterns in different portions of its range. The perennial Strobilanthes wallichii flowers annually in the eastern Himalayan portion of its range and plietesially in the western Himalayan portion (Wood 1994). Literature reports of life history for some taxa are ambiguous. For example, Robinson (1935) noted a 12 year plietesial cycle for S. consanguineus C.B. Clarke whereas Bowden (1950) indicated that this species flowers every year. Such discrepancies likely result either from misidentifications of or life history variations within taxa.




See also


Strobilanthes callosus
Strobilanthes kunthiana




References

Kata Kunci Pencarian:

• Plietesials
• Strobilanthes kunthiana
• Monocarpic
• Semelparity and iteroparity
• Strobilanthes callosa
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