As we move into April, we are in a fickle month. During these 30 days, we may receive cold and snow, as in 2013; rain, including thunder showers; or it's dry and quite warm, 70 or 80 degrees. Lengthening daylight mixed with warming temperatures revive plants that have been largely dormant for the winter and five months beneath the snow.

At sunny snow-free sites, we might see dandelions in bloom. Here, crocuses that began to open in March become more widespread and colorful. Grasses begin to green; new shoots push up from the soil. At the edge of receding snow cover in our yards, we may also find patches of snow mold. But there is plenty to see in the trees around us as well.

When thinking of flowers in trees, we are likely to look for blossoms of apple, cherry, plum, juneberry or lilac, all of which we will be seeing during warmer days of May. These blooms are more of what we call a typical flower, one that has petals (the colorful part) around the female and male parts. In the center is the pistil (female) with stamen (male) surrounding.

There is huge variety to this arrangement, but with tree blossoms of May, this is normal. Not so with the tree flowers of April.

Early-blooming silver maple and, a bit later, red maples, have florets somewhat like this. They have some colors, but differ from the blossoms. Male and female flowers are separate and usually on different plants. The tiny female flowers (pistillate) are red-purple while the equally small male flowers (staminate) basically just produce pollen.

With no leaves of trees, pollen readily drifts in the spring breezes from male flowers to female, assuring pollination.

Among many other kinds of trees, a different type of flower is produced at this time: catkins. These structures that are shaped long like hot dogs can now be found on the branches of willows, aspens, alders, hazels and birches. Those of willows and aspen opened as the furry buds a couple weeks ago. These opening buds gave us a look at what was to come in the warming season.

Though we may have used these as a remedy for “spring fever," they have been growing and now, in April, they mature as male or female flowers. Male catkins produce pollen and may appear more yellow; females are greenish.

With the alder, hazel and birch, male catkins were on the tree twigs all winter. Now in spring, they enlarge and swell with pollen. With no leaves on the trees, the pollen blows in the wind.

April is the month of catkins. By the end of the month, we’ll see more, but now in early April, the alder branches that are filled with these developing catkins.

Alders (speckled alder, sometimes called "tag alder") are small trees with numerous branches. They abound in the wetlands, along the edges of ponds, swamps and lakes, often with willows. We hardly take notice of them all winter. But during the longer days of March, the catkins take on a reddish-purple glow, and when we take a closer look, we may see the tiny yellow grains of pollen.

Female catkins are smaller and grow nearby, on the same plant. When they get pollinated, seeds form in the female catkins that later grow to be cone-shaped. They also persist on the plant. We can still see last year’s cones on these trees.

The smaller alders of the swamps introduce us to the numerous catkins of April.

Larry Weber
Larry Weber