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Willow catkins with bee. At right you can see a
willow gall (the brownish cone at the end of a stem),
which houses a midge larva over the winter. |
It's the time of year when attention focuses on the earth, bursting with color and texture after the long, brown winter. Scarlet tulips and saffron daffodils adorn yards, while dainty white or pink spring ephemerals like bloodroot and spring beauty cover the ground in wooded preserves. Early native flowers provide much-needed nourishment to early bees and other pollinators, and the activity around these blossoms can be frenetic.
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| Showy catalpa flowers |
But if we focus on these obvious botanical gems below, we risk missing out on an entire world of pollination happening above our heads. Some trees are renowned for their decorative flowers (think of the cherry blossoms along the Potomac, or gaudy white magnolias). Other trees have showy flowers but are not as famous, like the common suburban catalpa with its big leaves and orchid-like white flowers striped with purple.
Still other trees have subtle flowers that may go unnoticed, not only because of their distance from human eye level, but because of their understated appearance. These humble flowers, however, offer a bounty to our pollinator friends.
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| Willow catkin with fly |
Right now at the Sycamore Wetlands there is a willow buffet: swarms of bees, flies, wasps and other insects visit the fuzzy-looking yellowish catkins for pollen and nectar. There are very few flowering forbs on the Greenway at this time of year, so these abundant tree-flowers provide sustenance until later-blooming plants can catch up.
In a few more months we will see the pollinators move along to the crowns of honey locusts. Their drooping clusters of brownish flowers are rather scraggly and unimpressive, but they emit a strong, wonderful fragrance that envelops passersby while insects buzz noisily high overhead.
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| Honey locust flower clusters |
Both oak and birch trees have dangling catkins similar to willows and honey locust, but these flowers are generally wind-pollinated and not utilized by pollinators as a regular food source. Though not high-value as a pollen provider, oaks and birches are vital hosts for hundreds of species; their foliage feeds larvae of many butterflies, beetles, and other insects, which in turn provide meals for birds and their young during the spring and summer.
Next time you are out enjoying the spring flowers, be sure to keep an eye out for the small but essential flowers in the sky.
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| Early oak catkins |
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| Birch catkins |
