Friday Flowers: Noxious Weeds?

Painted Lady on Spotted Knapweed

About an hour west of our home is an area known as the West Perth Wetlands. The town of Mitchell transformed their old sewage lagoons into a series of ponds which attract large numbers of waterbirds especially during spring and fall migration. The surrounding meadows and woodlands are connected by a trail that extends into the town and along the Thames River.

West Perth Wetlands

It is a lovely area for walking and for birding. On a recent visit there we saw hundreds of shorebirds on the muddy flats. I became thoroughly confused while trying to identify juveniles and birds in non-breeding plumage. A flock of Bobolinks were in the thistles and weeds and because the males look far different than the ones I saw this summer, I did not know what they were until I downloaded my pictures.

Orange Sulphur on Spotted Knapweed

It was much easier to identify the many butterflies that were about that day. The preferred bloom was Spotted Knapweed, a non-native plant considered invasive especially in Western Canada. These plants in this family are copious nectar producers are are favoured in some areas by honey producers.

Seabrooke of The Marvelous in Nature wrote a recent post in defence of Purple Loosestrife called the Purple Monster. She pointed out that many invasive plants gain a foot hold due to human activity in highly disturbed areas. Her post is well worth reading to gain perspective on both sides of the coin of this issue.

Monarch on Spotted Knapweed

I do not have the knowledge to argue whether or not Spotted Knapweed is a significant invader in North America. The butterflies in these pictures have no concerns about the source of the nectar they are enjoying.

American Lady on a Butterfly Bush bloom

Near the parking lot a number of Butterfly Bushes had been planted along with Highbush Cranberry, Dogwood and other native shrubs. The Butterfly Bush (buddleia davidii) is an import from China and is considered an invasive plant in West Vancouver. But it is frequently recommended as a planting for butterfly gardens. The bushes at West Perth were covered in butterflies of different species.

American Lady and Milbert's Tortoiseshell on a Butterfly Bush bloom

Seabrook states in her post, "There’s no shortage of invasive species; Invasive.org lists 694 exotic plant and 228 non-native insect species on their website as well as 43 other organisms."

Invasive plants or not, I enjoyed their blooms and their visitors. And I applaud the efforts of those who have transformed the sewage ponds into an important nature area.