When we returned to the ranch from our Reno hiatus the black locusts (Robinia pseudoacacia) had finally leafed out. Not only had they leafed out but they had produced millions of creamy, white blooms. The blooms smell sooooooo good, adding a sweet, clean, refreshing quality to the air.
FYI, black locusts are quite toxic, every part of the tree including the seed pods are toxic. Horses that eat the tree can show signs of depression, diarrhea, colic and weakness.
Look closely and you will see the western tiger swallowtail: