It's morel season, and it pays to keep one's eyes open during walks along the wood verges. At least two species of morel grow here, but neither ever seems abundant. The one in the image is the only one I've seen so far this year.
The little yellow violet is Viola pubescens , a very common species here. There are places in the woods where yellow and purple violets grow together and make a lively combination.
The final image is of a section of Rock Creek; the water is relatively high due to recent rains. I have seen kingfishers, wood ducks and mallards here, and an Eastern Phoebe haunts the nearby bridge.