Vol. 169, No. 6 (July/August 2008), p. 746
Quick update: Many more flowers have, and continue to, come in on my Calathea concinna. After some unsuccessful pollinations using a No. 4 paintbrush (done by gently agitating the organs of each flower), I saw browning and wilting within 2 days.
However, after a recent experience wherein I saw the style shoot forward (with a barely audible *click!*), I decided to read up on the family in general, as there is little literature on C. concinna, but more information on the broader family.
It turns out that each style houses the pollen plate (“pp” in the above figure) and the stigmatic cavity (“sc”). When the trigger area (“ta”) is brushed or otherwise agitated sufficiently, a presumed turgor pressure is relieved (in 0.02-0.03s!) and the apparatus curls forwards. This is used to scrape pollen from the pollinator onto the stigmatic cavity, fertilising the ovules, and push a new payload of pollen onto the pollinator to repeat the process.
Therefore, it can be assumed (from this action, along with the short ~2 day viability period of the flowers) that both pollen and ovaries are mature and accessible provided the flower is open and the style apparatus triggers. Using a paintbrush, it can be advised that the best course of action is to wait until multiple flowers are open on your Calathea, use the bristles to trigger one, then move to the next and repeat triggering until all flowers are tripped.
This way, you can be sure that all (bar the initial) should have received some pollen payload.
I will continue to update on this course of inquiry as to the success rate of the pollination attempts.
sploopst 