I don't think it's either of them... The leaves are not carrot-like (look at the third photo). The seeds look like the ones from poison hemlock, but the leaves are different. Besides, my bunny loves that plant and she's been eating some from time to time for a year or so and she's completly fine, she never had any problem... And the brand of hay from which the plant comes from is relatively known in Europe...
What other plant could it be...?
(I won't feed her again with it until it's identified, just in case)
Thank you!
