Friday, September 19, 2008

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; 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.


  1. Great post Ruth..I have to go read the article on is taking over in our wetlands to the exclusion of everything else. Regarding the juve birds...There should be guide books on them. Here we have gulls and they are so confusing...

  2. It's amazing how beautiful Nature is - one has to slow down to take it in.

  3. Anonymous7:43 am GMT-4

    Weed or not, invasive or not, I'm with you, I enjoy the colors, the blooms and the visitors to them. Even dandelions are a quaint weed and we are constantly pulling them out of our lawns.

    Once again, good post on Friday Flowers and it looks like those beautiful butterflies enjoying your flowers as well.

  4. Beautiful pictures! Beautiful place to visit. Don't know why, but just wondering... do you feed the birds at your home?
    Thanks for helping identify my birds!

  5. Love the pics, and thanks for the butterfly IDs. I see butterflies around here, and usually have no clue what they are.
    It is so nice to see some wetlands that are allowed to be just that. Development has gone nuts around here, so that a wetland would be filled in and developed in a heartbeat. Never mind birds, bees and butterflies.

  6. I cannot say knapweed is ugly, I love its purple blooms but I must admit I rip it out whenever I see it. It is a plague here, the problem with it is that it releases a toxin into the soil that reduces growth of native species.

    I spreads so rapidly, my in-laws orchard has an infestation of it, in spite of years of ripping it out. It has effected the trees and they are slowly dieing as the weed destroys the soil. It has wiped out all the oregon grapeholly in that area too (which is a pity since it is one of the plants on the United Plant Savers watch list...)

    Still, just as I am a fan of thistle, I love the flower structure of knapweed.

  7. Noxious or not, it surely attracts the butterflies. Lovely pictures.

  8. Your butterflies are so clear and vibrant. I also like the weeds - they're pretty - especially the butterfly bloom bush.
    Thanks for these lovely pics.

  9. Many of the plants considered weeds were brought over for either food or medicinal purposes. Now we rely so heavily on pharmaceuticals, as well as the convenience of the mass produced standard veggies, we've lost the art of their use.

  10. It's nice that we humans find ways to let nature back into areas we "borrowed" for a time. The reclaimed lagoon looks like a great place for wildlife now. Thanks for sharing such colorful, cheerful photos, showing just how such a reuse is a good thing.

  11. Your West Perth picture has the quality of a fine painting, and such an ethereal sky!

  12. Michelle- Thanks...I find the Sibley Bird guide great for IDing juvenile birds.

    Jean- Always beautiful, always changing.

    Cheryl- We do have a negative attitude toward many weeds and overuse herbicides. The butterflies need the weeds.

    Julie- I put feeders out in the winter. I get too many house sparrows and squirrels in the summer and they do make a mess.

    KGMom- I think these wetlands will be protected for some time. We are slowly learning the value of such areas.

    Jaspenelle- I know the problem is worse out west where knapweed first was introduced. It has spread here from the west coast. Time will tell how much of a problem it is here.

    NCMW- Thanks!

    Wendy- If the butterflies are on a plant they love, they will stay still long enough for a picture. I find noon hour is the best time to picture them.

    CS- That is a topic I wish I knew more about. The medicinal use of plants is an art in my opinion.

    Zhakee- The lagoons were pretty disgusting, especially the smell. It is wonderful to see how nature can regenerate.

    FM Doc- The day was 100% perfect. The clouds roll in from Lake Huron which is just a little way to the west.

  13. Thanks for the linkage, Ruth! I'm afraid I don't know a whole lot about knapweed, like the Himalayan Balsam it's not something I've encountered much around here. Out west, though, where I worked one fall in the Okanagan Valley, it was a real nuisance, and a problem weed that was easily filling in disturbed areas.


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