Well, unwittingly, anyway!
It is illegal to pick Trillium flowers in many states, New York being one of them. When the flower is removed, the plant is seriously injured and/or may die. The seeds of Trillium are spread by ants and mice. The outside of the seed contains a fleshy part that the ant or mouse eats. When it passes through their system, it is then “ferilized”, and a new plant then begins. We have never had many Trillium plants here, but the mice or ants must have been busy, as we now have many plants in one area!
The leaves of the Trillium are actually underground, with the three leaves that surround the flower actually being a bract. The type we see here in the northeastern US are called Trillium Grandiflorum.