AY Honors/Nutrition/Requirements 2
From Pathfinder Wiki
You can also make flour with the roots or pollen of cattail and with acorns. Though acorns may be found in abundance, it is a lot of work to process it into flour. Other nuts (walnuts, hickories, hazelnuts, etc.), though often less abundant, are a little easier to process into flour as they do not require leaching to remove tannin. See the answers to the Edible Wild Plants honor for details.