The second half of August always gives me mixed feelings of melancholy and joy. It is sad that the summer is rapidly coming to a close; the campers go home and most of the staff return to school for the fall. Late August is also the start of another creature’s departure, the Monarch butterfly. It’s this migration that makes me happy because we get to see thousands of butterflies as they make their way south towards Mexico. You can see many Monarchs in Rondeau during this time of year as they stop to feed on plants such as Blazing Star and New England Aster to refuel for the next stage of their journey. However, not every Monarch you see is migrating south. Some of the butterflies are the ones that have been around all summer laying eggs, while others are those that hatched here in Rondeau and will migrate south to Mexico. You can tell the difference between the breeders and the migratory individuals by looking at them. If they look faded and/or are missing parts of their wings they are local breeders and won’t be going south. If they are bright and shiny orange they are more likely to be migratory.

With the upcoming Monarch Festival, our butterfly hike and the butterfly tagging demonstration, I don’t want to expound too much upon butterfly facts so I’ve decided to write about another bit of orange you can see this time of year. It’s a small, horn shaped flower that can readily be seen along Marsh Trail that goes by the name of Spotted Jewelweed.

Spotted Jewelweed is not only attractive to people, but is also a magnet for hummingbirds. The colourful flowers will produce 2.5ml of nectar per day that is about 40% sugar: a great treat for hummingbirds that are trying to fatten up for the long flight south. Hummingbirds aren’t the only visitors to these bright flowers; a number of different bee and wasp species will also feed on the nectar they produce. However, some of the bees and wasps can’t reach far enough into the flower to get the nectar so they chew a hole through the back wall of the flower. Unfortunately (for the flower) this means they don’t help pollinate the flower like hummingbirds do.

It’s vitally important for Spotted Jewelweed to be pollinated and produce seeds because unlike most wildflowers, it is an annual. Each year the new plants grow from seeds and not from rootstalks from the previous year. If no seeds were produced during one summer that would mean no new flowers the following season. To ensure its survival Jewelweed will also produce small flowers that will never open, but will self pollinate on the inside to produce seeds for the following year.

The real treasure (pardon the pun) of this plant is the seed pods. As summer fades to fall, the seed pods ripen and swell up. Once they are fully ripe a strong breeze or a slight touch by an animal or human hand makes the pod explode. This explosion gives this plant its other common name Touch-me-not. The explosion causes the seeds to be thrown up to 1.2m (4ft) away.

Interestingly, the self fertilized seeds do not explode as powerfully and are therefore not thrown as far as cross fertilized seeds. Some scientists believe that because self fertilized seeds are extremely similar to the parent plant the seeds will do better in similar soil types so the closer they land to the parent plant the better. Cross fertilized seeds have more genetic variability and will be better equipped to deal with slightly different soil conditions so further away is better. So if you get a chance later this summer and fall, go out and touch some Touch-me-nots and see if you can guess if they are self or cross fertilized seeds.

If you have any questions about Jewelweed or anything else nature related please email me at kipling.campbell@ontario.ca

Explodingly Yours
Kipling