Mellow yellow

Daffodil (Narcissus x hybridus tête à tête)

Buttercups

Into the woods! 
Wood anemones aka. windflowers or thimbleweeds (Anemone nemorosa) & fig buttercups aka. pileworts or lesser celandines (Ficaria verna formerly Ranunculus ficaria).

Topinambur

Helianthus tuberosus aka. Jerusalem artichoke, sunroot, earth apple, or sunchoke