I've previously mentioned plants that release their pollen from holes in the ends of the anthers. See handsome Harry and the laurels. Oneflower pyrola is in the same family as the laurels, and does the same thing, but a little differently. In the previous species, the pollen hole was undifferentiated from the rest of the anther. In this one, there are small brown tubes at the ends of the anthers that deliver the pollen.
The picture here gives a little better idea what I was dealing with when I took the closeup. I will confess that the pile of leaves in the background was done by me to improve the contrast.