How is this tall plant with dandelion-like leaves called?

Family: Asteraceae Form: Herb Origin: Native of Europe, Asia and northern Africa. Flowers/Seedhead: Many small flowers (florets) in heads surrounded by bracts 6–9 mm long at flowering (to 15 mm in fruit). Flowers spring to autumn. read more

It looks like Senecio vulgaris ( the english name is Common Groundsel, I think ). If it is, it’s a very common garden weed, growing fast and almost everywhere. read more

To be certain, break a leaf in half, if you get some sticky milky substance that weeps out, it is milkweed dandelion. Milkweed dandies are poisonous and should not be eaten, unlike dandelion. My husband and I have a 5 foot 22 pound iguana who loves dandelions. read more