ENTS,
I thought at least a few members of the group would get a kick out of this. The three attached photos were taken after mowing the front yard on Wednesday. I have a very natural lawn.
 
What you see (look carefully) are very old seedlings of Eastern Red Cedar, Juniperus virginiana. Picture 00785 shows one, and the other two pictures show two each. Whenever I mow the grass, the trees get cut down, and they just keep growing back (just a couple of inches). We've lived here since 1985 and I'm not sure if these trees have been in the yard all that time or not. I'm sure they've been there at least 10 years, possibly even 15, 20 or more. I really don't know. But they sure are tenacious. They get cut but keep coming back for more.
Of course I'm not one of those lawn fanatics. I mow the grass and do nothing else to it. No fertilizing, no aerating, no de-thatching, no use of weedkillers, no watering except for rainfall, etc.
The plant species include many species of grass, at least two species of hawkweed, thistle, narrow-leaf plantain, broad-leaf plantain, white clover, some kind of cinquefoil, dwarf dandelion (Krigia virginica), regular dandelion, sweet everlasting, multiflora rose, common field daisy, evening primrose, at least one species of fleabane, horseweed (another fleabane), various species of moss, reindeer lichen, and a very rare orchid (I can't go into detail on that). Near the edges there can be found a few species of boneset, a couple species of goldenrod, etc. In some areas along the woods there can be found Stiff-leaved Aster, yellow star grass, and hairy blazing-star. And there's more. But you get the idea. I like a natural lawn, and have no interest in a pure grass lawn. Lawns like that are a waste of time, money and resources.