Rattlesnake-weed (Hieracium venosum)
The purple veins of the leaves make this plant noticeable in my open woods long before it flowers. In fact, the puny yellow flowers are so mismatched with the fleshy leaves, that they are somewhat of a disappointment. I have never been tempted to eat it.

Salsify, Oyster plant (Tragopogon porrifolius) or
Yellow goat’s beard (Tragopogon pratensis)
These two hybridize and mingle, making it difficult to tell them strictly apart. The root of this biennial is delicious, but almost impossible to find in the first year, when it is tender and sweet. The seed head looks like a dandelion on steroids.

Hawkweeds (Hieracium species)
There are a dozen or so hawkweeds in my area, all with yellow (or orange) dandelion-like flowers. None of them are poisonous, but the leaves and flowers are way too bitter for me so I don’t eat them.

Sow-thistles (Sonchus species)
I first met this dandelion-like plant in New Zealand, where she was introduced to me as one of the favorite greens of the Maori. It is exceptionally mild tasting and delicious in salads, or cooked, especially if you can find a species that is not too bristly.