By chance, one of the dinner guests brought a platter bearing an attractive painting of a dandelion. Within a day or two, the yard had once again become a sea of dandelion seedstalks.
Afterthoughts: If dandelions were spreading to natural areas and displacing native species, I might get serious about clearing them from the yard, but their edibility for wildlife makes any invasion of woods and fields unlikely. They could also be a useful, non-mechanical means of aerating a lawn. When the urge to weed them out strikes, cut them off just below the rosette of leaves, so that the decomposing taproots will serve as channels for rain to percolate into the soil.