One of These is Not Like the Others

The soaker hose did the trick- my plants were happily growing upon my return today. To the right is a photo of one of the broccoli plants which had a growth spurt while I was gone. Before I left I stuck a couple lettuce seeds in a pot just to see what they'd do. I thought it might be too hot still, but one of them has sprouted. The onions look about the same.

The carrots have also been growing. I am curious what these other little seedlings are that have sprouted in both the carrot pots and one of the onion pots. I haven't decided yet whether to pull them out or see what they turn into. See the middle of the photo below for the odd man out.