My kitchen has become a small scale operation – thinking fruit pies, jams and jellies?
Caulophyllum thalictroides (Blue cohosh) blue seeds will easily pass for blueberries but unfortunately are poisonous if ingested in large quantities. That’s very improbable to happen though because what seems like a big berry is actually a single huge seed surrounded by a thin fleshy and blue seed coat.
More likely to lose a tooth or two than being poisoned!
On the other hand, Podophyllum peltatum (Mayapple) fruit it is/has been used to prepare jams and jellies. The big size fruit (hog apple, wild lemon, Indian apple), when fully ripen has a light yellow colour and a persimmon fragrance (in my opinion). It is actually the only part of the plant that’s not toxic.
To ensure good germination seeds of both species have to be placed in moist storage right away. They belong to a large category of species with hydrophylic seeds (intolerant of dry storage).
Also, both species are important North American medicinal woodland plants.
PS. In case you have available large quantities of mayapple fruits to make jam, be kind and promote a sustainable harvest (always) by discarding the seeds in a nearby wooden area.