Flowers allowed to remain on the parent plant tend to last anywhere between 1 to 30 days* in terms of their pollination period. This large variation (x30) in longevity remains unexplained.

Floral longevity, the length of time a flower remains open and functional, is an important trait in pollination biology. Optimal floral longevities balance flowering costs against the rate of pollen export and receipt."

[ source below ]

A 2024 research project from Macquarie University, Australia, which examined 1,452 species, found that there is a significant difference in the lifespans of flowers depending whether they are 'zygomorphic' (i.e. bilaterally symmetric, such as orchids) , or 'actinomorphic' (radially symmetric, such as daisies).

We find that zygomorphic flowers last on average 1.1 days longer than actinomorphic flowers, a 26.5% increase in longevity, with considerable variation across both groups."

Source : Biology Letters, Volume 20, Issue 6

The reasons for the flower-type differences also remain unexplained.

Further study could determine, for example, whether zygomorphic flowers spend less than comparable actinomorphic flowers on resources such as pollen, nectar or water in compensation for their extended lifespan. Flower size and number trade-offs, and their interaction with the trade-off between floral longevity and floral symmetry, also bear investigation. Flower economics can thus expand our understanding of this critical aspect of plant reproduction, and the evolutionary compromises shaping the diversity of flowers around us."

[ Source as above ]

* Note : Of the flowers tested, the most common lasting-time (for both types) was around 1 day.