Coastalplain Hawkweed - Hieracium megacephalon

Coastalplain hawkweed (Hieracium megacephalon) is one of many such Asteraceae members that get mistaken for dandelions.  It is not one, of course, and is the sole member of this genus found in Florida.  It is found nearly statewide here, but is not an endemic as it also has been vouchered in Georgia.
Some might also call this a "weed", and it fits that description a bit since it is common in a wide variety of upland habitats and tends to reseed well into disturbed areas. "Weeds" are not necessarily unattractive or undesirable, however. Coastalplain hawkweed produces showy flower heads that can be up to 1 inch in width. The lemon yellow petals open in the morning and close by mid-afternoon. They attract a variety of pollinating invertebrates.  Flowers can be produced year round in frost-free portions of the state, but elsewhere are visible from spring to late fall.  The stalks are about  18 inches tall when grown in sunny locations.
Coastalplain hawkweed is a perennial forb. The leaves are elliptical in shape and normally 2-3 inches long. The leaves and stems are covered by coarse "hairs". 
This is not a species I've ever seen offered by commercial nurseries, but it would be easy to propagate from seed. As mature seed is available most months, collect a few from sites where this would be legal, and sow them slightly below the soil surface. Just realize that it is likely to spread once established.