The descriptions are quite cryptic so there's nothing I will add.
Buffalo Bird Woman's Garden by Gilbert Wilson: no mention at all.
Plants of Haida Gwaii by Nancy Turner: no mention at all.
The Sioux Chef's Indigenous Kitchen by Sean Sherman & Beth Dooley: p94: ". . . every part of the plant is edible at different times of the year.
The cattail roots or rhizomes are starchy and can be dried and ground into flour and used to make into biscuits; but that's a lot of work,
and, to be honest, I prefer the upper parts of the plant."
Native Harvests American Indian Wild Foods and Recipes. by E. Barrie Kavasch. p124: pollen was harvested from the male spike (above the female spike)
and used as a flour extender to 50%.
Wildwood Wisdom by Ellsworth Jaeger. p254 & p255: rhizomes boiled into a starchy gruel or roasted.
They were then dried and pounded into a meal. Pollen pancakes made with 50% pollen/flour.
I might have other references but I've forgotten. Looks like you are in for some experimental dinners!
I confess, and this is a big confession for someone that has been foraging for a very long time, I have never made flour out of anything - there, it's out
The pollen is excellent. It comes off in huge amounts when the spikes are ripe. Just gently bend the stem until you can put the spike into a paper or polythene bag and then rattle it around a bit. The pollen will fall to the bottom of the bag. Don't damage the spike, because it'll make release pollen for several days.
It's bright golden yellow, really protein rich and it's not much flavoured but it does add nutrient to flour
M
I confess, and this is a big confession for someone that has been foraging for a very long time, I have never made flour out of anything - there, it's out
I'll be doing that , thanks Toddy.