For daffodils, the instructions just say to throw them up in the air and plant them where they land -- this is called "naturalizing" and looks like what has been done here. Then you have to avoid mowing them down with the grass later, to allow the leaves to gather nutrients for the next year's blooming.

Daffs were the Rube's favorite flower back when he was a gardener -- he used to have dreams about them magically coming up in the spring, much more in number and varieties then he actually had planted. He can't really remember the names of the varieties now, but Fig 1 shows some with bright yellow trumpets and white petals; Fig 2 he thinks are narcissus because they are much smaller then regular daffs, and Fig 3, yellow/yellow, may be the basic "King Alfreds".

Fig. 3 also illustrates one of the less picturesque features of Central Park -- areas are always fenced off to try to help them recover from the very heavy foot traffic of legions of New Yorkers.