in Thoreau’s Journal:

Boiled a handful of rock tripe (Umbilicaria Muhlenbergii) (which Tuckerman says “was the favourite rock tripe in Franklin’s journey”) for more than an hour. It produced a black puff, looking somewhat like boiled tea-leaves, and was insipid, like rice or starch. The dark water in which it was boiled had a bitter taste, and was slightly gelatinous. The puff was not positively disagreeable to the palate.