|A few spring beauties surrounded by the invasive lesser celandine|
|Lesser celandine along the trail where native flowers used to be|
Last year I was disheartened to find that the lesser celandine
, that attractive but aggressive invader, had spread over the land that once belonged to spring beauties and trout lilies. I am sorry to say that it looks like the non-native continues to make inroads.
|Pachysandra, upper right corner; snow drops, bottom; spring beauties,
center; lesser celandine. There are also stems of another alien,
Lesser celandines, with the help of snow drops and pachysandra, all of them garden escapees, have taken over the forest floor along my favorite nature trail. Later on, garlic mustard will show up in all the same places, but now it is not in sight. Snow drops were in bloom the last couple of weeks and now they are past their prime. This is another delightful but aggressive invader which brings joy to the hearts of many with its early blooms. Spring beauties struggle to survive hemmed in by all these newcomers to the land. Trout lilies face the same predicament in these areas.
|A patch of lesser celandine|
This spring I want to see how our native spring beauties and their pollinators are faring among the many introduced plants. So a few days ago I sat on my little stool on front of a patch of lesser celandine. It was a warm and sunny day and insects were quite active, including some gnats that enjoyed attacking my ears and forehead. During my forty minutes of observation I saw a number of little dark insects approach the patch and inspect the blooms by briskly hovering above them. Only one landed on a flower and stayed long enough for me to recognize it as an Andrena bee, the kind that would be loading her leg baskets with pollen from spring beauties if there were any around. Soon it left without attempting to gather anything from the flower. Perhaps it was just using it as a perch to pause during an exhausting and frustrating search for its favorite food.
|Another patch of lesser celandine, near a stream|
I continued my observations two days later. For more than an hour I walked along the trail illustrated above. I kept my eyes open for flower visitors and made frequent stops. I found only a handful of spring beauties nearly smothered by the lesser celandines. Even that very low number managed to have a few visiting bees. On the other hand, the bright yellow blossoms of lesser celandine remained neglected by anybody other than a small gnat and a beetle.
Finally, I sat for half an hour on front of another patch of lesser celandine, as on the previous time and intently looked for flower visitors. Finally a honey bee showed up and methodically worked the flowers. Let us remember that both honey bees and lesser celandines are European imports. There were no native pollinators in sight.
I should be glad that the lesser celandines don't get pollinated; but I can't. The variety brought from Europe propagates primarily by small bulbs (bulbils) with no need for pollinators. It reproduces this way only too well. Its abundance and the growing scarcity of spring beauty flowers forces the Andrena bees to travel longer and longer distances to gather pollen for their young. As a result, they can raise fewer and fewer babies each year. Both the flower and its pollinator continue to lose ground to the invaders.
|A spring beauty and its pollinator, a rarer sight each year|
List of articles
Beginners Guide to Pollinators and Other Flower Visitors
© Beatriz Moisset. 2012