Upon inspecting the yard I realized some seedlings had germinated in the knot of a rotting log. The leafy green to the right is our native Woodland Poppy, Stylophorum diphyllum, the other is all Creeping Charlie, which were likely dropped in there from a plant that grew over the hole (note the stalk to the left climbing up the side).
Woodland Poppy seeds have elaiosome on them and are thus dispersed by ants, but even seeds that don't have this substance on them can still be dispersed.
The granary of the common pavement ant, Tetramorium species E. are full of seeds to some sort of grass. While these seeds are eventually ground up to be eaten, the ants collect too many of them and they end up germinating before they're eaten.
At the stands to a number of grasses you can often find ant hill from species that likely planted them.