By Laura Gardner, Master Gardener
Now that the gardening season has winded down, I’ve turned my attention to some interesting reading. On my nightstand there are some little books that I’ll pick up and read a few snippets just before bed. They are part of a series called “Pedia” published by Princeton University Press.[i] The word “pedia” comes from the Greek word “paideia” for “learning” or “education.” There may be a perception that University presses publish only heavy academic titles. However, many do publish titles that are suited for the general reader. In this particular series, so far it covers the subjects flora, insects, trees, fungi, geology, dinosaurs, birds, and neurology. The petite clothbound books are like miniature encyclopedias, each with around 100 entries on a wide range of topics. Some of the entries are so fascinating that I needed to find out more.
Here are three entries that show gardeners the symbiotic relationship between insect species such as bumblebees, beetles, ants and selected plants:
In “Florapedia,” there is an entry for the plant Cornus canadensis (Bunchberry), a native of the Dogwood family that can be found in some of our Peterborough County forests. Its flowers are said to be capable of the fastest movement in the plant world. As a self-incompatible plant (i.e., unable to self-pollinate), it relies on a unique process of pollen transfer. Amazingly, it has the ability to project its pollen at a rate of 4 metres per second—more than 2,000 times the acceleration of gravity (p. 20). When an insect touches on an unopened flower, it triggers the firing of the pollen through the release of stored energy. The pollen then transfers to the insect which in turn moves on to another flower to cross-pollinate. Larger pollinators such as Bombus (Bumblebees) are required to initiate the opening of the flowers; although flowers that open by themselves are able to fire the pollen at a distance of about 1 metre to adjacent plants.[ii]
In “Treepedia,” we learn that Magnolia trees were among the first flowering species on the evolutionary scale (about 100 million years ago) and that they were and still are pollinated by beetles (p. 82). Magnolias developed hardened carpels (female reproductive parts) so they are able to tolerate the beetles’ chewing mandibles.[iii] The beetles are attracted to the large, strongly scented flowers as well as the pollen and other secretions. Pollen grains are readily captured by the insects’ hairy bodies—which are transferred to other flowers.[iv] Some gardeners may only think of bees as being pollinators and don’t think of the importance of beetles. Some other species that are pollinated by beetles here in Ontario include Asimina triloba (Pawpaw), Nymphaeaceae spp. (Water Lillies), and Lindera benzoin (Northern Spicebush).
In “Insectopedia,” the topic of seed dispersal, the term myrmecochory is explored. More than 4,000 plant species rely on ants for seed dispersal. Ants are attracted to the nutritious fatty seed coats called elaiosomes and take them back to their nests. The remaining unwanted parts of the seeds are discarded near the nests and subsequently germinate into new plants (pp. 155-156). Have you ever wondered how some new plants pop-up some distance from the parent plant? Species such as Sanguinaria canadensis (Bloodroot), Trillium spp., (Trillium), Scilla spp., (Squill), Hepatica acutiloba (Sharp Lobed Hepatica), Viola spp. (Violets), are just a few examples of plants that can spread with the help of ants.
These little books would make a nice gift for any curious gardener, amateur botanist, or nature enthusiast.
[iii] Evich, Philip. The Botany of Magnolias. Smithsonian Gardens. Online: https://gardens.si.edu/learn/blog/the-botany-of-magnolias/
[iv] Hooks, Cerruti R., and Anahí Espíndola. Beetles and Pollination. Maryland Agronomy News. Online: https://blog.umd.edu/agronomynews/2020/06/29/beetles-and-pollination/