Lobelias of the Krug Forest
I have always loved wetlands, be they swamps, bogs, marshes or the shoreline of a favorite river or lake. The Lobelia family are some of my favourite flowers to encounter in wetland habitats. During the July Wild Plants apprenticeship weekend we were fortunate to meet two beautiful Lobelias on our trip to the Krug Forest.
In a low, moist, open area on the sunny edge of the forest, we found an abundance of cardinal flower (Lobelia cardinalis) growing in a lush tangle of grasses alongside water hemlock (Cicuta maculata).
Cardinal flower immediately stands out for its shocking red colour– so red that my camera lens can’t seem to capture its depth and vibrancy. Cardinal flower is notable as a food source for the Ruby-throated Hummingbird. This scarlet red colour is not common in nature, yet, according to the Audubon Society, hummingbirds’ eyes are especially sensitive to colours in the red to yellow range.
While being sources of food for both Hummingbirds and Swallowtails, the Cardinal Flowers are not abundant enough to provide any significant food for birds or mammals according to John Eastman, author of The Book of Swamp and Bog. So intertwined are L. cardinalis and the Ruby-throated friends that John Eastman writes, “Cardinal flower abundance not only depends upon hummingbirds but also reflects, to some extent, their own abundance.”
L. cardinalis’s long tubular flower exhibits an exciting characteristic called protandry, in which the flower seems to “change sex” from male to female. First, the flower displays pollen-bearing “male” stamens. When the pollen is dispersed, the stamens decline, and pistils (the “female” part) extend, ready to receive pollen from another flower still in the staminate stage. This sex-sequential behaviour stands in contrast to most other flowers, whose staminate and/or pistillate parts remain static over the course of the plant’s life.
We saw Kalm’s lobelia (Lobelia kalmii) growing along the moist, sunny edges of a swampy wetland. The delicate stalks of this tiny plant would be easy to miss if it were not for its blue-violet flowers. Kalm’s lobelia prefers calcium-rich soils like fens.
Despite looking this plant up in my wild plant books, and browsing reputable wildflower websites, I wasn’t able to find many answers to my questions about Kalm’s Lobelia: what insects pollinate this plant? Do any herbivores browse on it? It seems that science doesn’t have much to say about this diminutive wildflower.
All members of the genus Lobelia contain the alkaloids lobeline and lobelamine in various quantities. Lobelia inflata in particular is used in western herbalism for smoking cessation, among other applications, and the usefulness of this plant is attributed to these alkaloids. But take caution: as we often see in herbalism, the most potent medicines can be harmful in large doses. If you were to consume a bowlful of Lobelias, their alkaloids could cause nausea, vomiting, diarrhea and convulsion. Plants are powerful!
I’m grateful for the opportunity to meet these two Lobelias again!