It’s often good to approach plant habits from their point of view instead of from ours.
Why does a plant act in a certain way? Ferns, for instance, will often shed old fronds when new ones emerge. These dead fronds lie in a heap at their base. This looks pretty messy to many of us—that useless brown foliage just lying there. But wait, what does this habit do from a fern’s perspective? It makes a very good mulch, preserving moisture for the roots.
When I noticed that the white gentian (Gentiana flavida) in the Morton Civic Center Habitat Garden bloomed a full two weeks before the purple-blue bottle gentian (Gentiana andrewsii), I thought that was curious. Both of these gentians have closed petals—it takes large bees to open them for pollination. So why would the white gentian bloom any earlier? They are both practically the same species, and have been known to hybridize in mixed settings. Probably the whites were a variation in the blue ones many, many years ago.
Would the bees have anything to do with this difference in bloom time? It is well known that bees see three colors: ultraviolet light, blue, and green.They are most attracted to purple, violet, and blue. In terms of our two gentians, the purple bottle gentian would get most of the bees. The white one would be left out, unless it was able to bloom at a different time. Perhaps over a large expanse of time the early-blooming white gentians were the ones that got the pollinators and were able to survive by blooming first.
— Douglas Macdonald
Doug Macdonald has been steward of the Morton Civic Center Habitat Garden since 2017. He was formerly a curator at the Chicago Botanic Garden.
The photograph of Doug is by Peter Laundy. Doug took the pictures of the gentians.