I'm unfamiliar with this species, but allow me.

[He promptly plucked a leaf lose and licked it without hesitation, pausing thoughtfully as he processed the plant.]

It doesn't contain any toxins that would be considered poisonous or dangerous to humans. It does, however, contain very high levels of oxytocin, a hormone produced by humans. It encourages prosocial behaviors, such as facilitating trust, empathy and attachment between individuals.