Beginner Gardening: what is this?? gowing under bird feeder, 0 by Gardenia731

Gardenia731 wrote:
I am so glad you posted this picture. I knew it was a seed from my Cockatiel seed mixture but I didnt know what it was. I let it grow thinking it might be broccoli but it was too tall. Then it started flowering these pretty yellow sort of clustered lil bunches. This is how tall it is as of today. I found it so amazing how something I dont water or feed can grow so large and my dogs pee on it every day. LOL!