Can there be any hallucinogen herbs that are not poisonous?

Depends what u mean: by 'poisonous.' Many hallucinogens are also strong anticholinerigic drugs , like aminita mushrooms and belladonna, and those can cause severe problems, especially in older people. Mescaline, peyote and psilocin are herbal derived hallucinogens which in low doses produce an hallucinogenic experience without many medical side effects, but a bad trip, with psychosis and danger 2 self/others possible