I found American Hazelnuts in bloom today.
This monoecious shrub has two separate flowers. Look for the male (staminate) and female (pistillate) flowers on the branches of the same plant.
Female flowers of Corlyus americana
The female flowers are tiny and very inconspicuous. Look for the violet-red stigmas and styles poking out of scaly buds along the branches.
Male flowers of Corlyus americanaThe male flowers are numerous, usually clustered and very conspicuous.
The tightly-closed "catkins" (on the left) first appear in the fall - along the branches near the tips. They don't open until spring. I noticed them starting to pop a couple of weeks ago.