Promise that you will take some more photographs when these open up, which won't take long. Just leave them alone to develop. These will be spectacular. glib, what you've said about mycorrhizal relationships is true (though stinkhorns are almsot always associated with hardwood trees), but removing the fruiting body does not take away the mycorrhizae. That part of the fungus organism is alive and well in the soil. Spaghetina, stinkhorns (including your lattice species) are often brought in with hardwood mulch. I've also seen it appear on or near the stumps and dead roots of hardwoods that have been removed. Just doing some recycling.

Oh believe me, we weren't even thinking of eating them. I just wanted to make sure they won't harm the kids if they come in contact with them. Thanks for the link. I tried to find something prior to posting here and had little success. I know jack about mushrooms.....

Update. Found another one today growing around the same section of the pot, and maybe another one I'm not sure. I am interested in finding out what kind this mushroom is. I am a bit sure why they're growing is because I have increased the watering as the sunflowers recently started drooping from the top and u had to tie them up.

From what I can see, It appears to be a fall oyster mushroom, which is just plain old pleurotus ostreatus fruiting under fall conditions. Perhaps it is some localized variety of pleurotus or other subspecies, but it looks like the same pleurotus that we find here in the midwest. A mycologist might not be so quick to jump to the same conclusion that I do, but that's what it appears to be to me anyways. From what I understand, it's the exact same mushroom as the white summer variety but it takes on a richer color and flavor during the cooler months. If not sure of your id, take it to a local expert before eating.