Meadow Salsify, Tragopogon pratensis FataMorgana Here is a link that might be useful: wikipedia - Tragopogon pratensis

you may think it's an interesting plant, but it's still a weed... grows really big, and the side stems, touching the groud make roots and the seeds... i spend a lot of time trying to get these out of someone's garden... :D

I would suggest using the site noted above or looking up each plant in the mix individually and add "seedling" to your search. You may get some other images to compare to. Using botanical names in your searches can help filter out some of the chaff in your search results. Other than that, seedlings are notoriously hard to id. Go back through enough posts here and you will see that immature plants are tough even for the experts. My suggestion is to leave what you don't know. If you want to weed, only pull the stuff that you know and don't want - the easy stuff like grass, lamb's quarters, purslane, ragweed, or whatever is the common stuff in your location. As the seedlings get bigger, they will be easier to ID as "wildflowers" or "weeds." FataMorgana

Papaver somniferum, a breadseed/peony/opium poppy. Not a US wildflower - thought to be native to the mid and far east. Either someone dumped the seeds there or other poppies were growing there previously. They don't bloom in my area until midsummer.