For those grasses that seem shy on producing pollen, ie. very few anthers dehiscing, can I cut the flower heads and allow them to dry and they will shed their pollen naturally into a container?

Will a paper bag over the flowering heads become filled with pollen?

I am having trouble collecting the pollen when I cannot see it! As grasses are wind pollinated the pollen is small and difficult to collect on a paintbrush.

Does anyone know if grass pollen looses its viability quickly?

I am working with Panicum, Miscanthus, Stipa, Molina, Pennisetum...

Any help is appreciated.
With regards
Alan (inUK)

Is it not possible at all to move the plants near each other? Generally the way I've seen it done with grasses is to put male and female inside a piece of dialysis tubing, which you flick a few times a day for a few days to ensure pollen movement. What if you cut off the flowering stalk of the male and put it in some water next to the female? Pollinating grasses with a brush seems likely to be kind of low yield. I could be wrong...like I said, I haven't done any work with grasses myself.