Animals Can Be Gay & So Can Mushrooms, Says 'Queer Planet' Doctor

Humans and animals aren't the only living organisms with same-sex couples ... some plants and fungi are also essentially lesbian and gay -- so says a pro who knows all about this.

Dr. Patricia Kaishian -- who worked on this new Peacock doc all about queer animals -- has been researching plants and fungi for years ... and she joined us on "TMZ Live" Thursday and shared some of her strangest findings ... same-sex reproduction!!!

It's pretty incredible, the good doctor says the plant and fungi worlds are way more complex than simply being comprised of just males and females ... and she says some organisms have figured out how to have offspring without a mate of the opposite sex.

Some of these findings -- most notably among mushrooms, as she explains -- are included in the new Peacock doc about animal sexuality ... and she reemphasizes that regular animals can for sure be fluid in their sexuality -- a phenomenon we've seen out in nature.

It's long been known animals have gay and lesbian sex, but the same going on among plants and fungi is new and important, information ... and Dr. Patricia is expanding on the topic in her upcoming book, "Forest Euphoria."

So we've got queer lions and whales, sex-changing fish, pansexual monkeys and now gay mushrooms and plants ... it's like wildlife is mirroring society among us humans.

One big difference ... Dr. Patricia says animals don't discriminate against other animals for being gay. Huh, imagine that!