2020 July 26

We were walking down our road on July 18, 2020, when we noticed this plant with purple flowers groing in the rip-rap[1] that the road commission put in to stabilize the slope beside the road:


The plant was pretty big, here it is with Sam for scale (she is 5’2″ tall)


This appeared to be something new, at least, none of us recognized it as something we’d seen before. The blossoms are pretty substantial, and a very nice shade of purple.




Each flower ultimately makes a long, thin seedpod, with each pod probably containing a few dozen seeds.


The leaves are long and thin, with a red central vein and red edges.


As it turns out, a local author published a book on the local flowers in the Keweenaw about a decade ago, called Blooming Seasons, and we have a copy. It is almost entirely high-definition pictures of flowers, organized by blooming date, with the common and scientific names of each. And, looking at the flowers that bloom here in early July, we quickly found our subject: it is Fireweed, Chamaenerion angustifolium.

Even though we hadn’t seen it before, it turns out to be (a) native, and (b) actually pretty common. They grow all around the northern hemisphere, as the seeds have little parachutes and they are able to spread widely. The thing that stops them from being an aggressive invasive species is that they apparently need a lot of sunlight and don’t do well when there is a lot of competition from other plants. Instead, what they do is specialize in colonizing soils where nothing is growing, like rocky ground and burned-over areas.

It is particularly well-known for being one of the first plants that grows back after forest fires, hence the name “fireweed”. It turns out that if the seeds land somewhere that there is a lot of competition, they don’t sprout right away. Instead, they stay dormant in the soil. They can wait for a long time, maybe 50 years or so, until something catastrophic happens to the other plants. Then they sprout and grow quickly, sometimes completely dominating an area until the tree seedlings can take hold, grow back, and eventually shade out the fireweed[2].

Apparently, it was considered a rare plant in England until World War II, when it suddenly had its chance to colonize bomb craters, giving it the name “bombweed”.

So anyway, it looks like it is going to colonize alongside our road for a while, since nothing much else is growing between the rocks. In fact, the road is currently being completely reconstructed following the big flood two years ago, which means that the sides of the road are going to be pretty much rock and bare soil for a while. This is fine with me, it is a pretty plant. Definitely nicer than the spotted knapweed.

[1] “Rip rap” is coarsely crushed, angular stone that is placed to prevent erosion. Around here, it is mostly basalt “poor rock” from the mines that was excavated and piled up to make the tunnels so the miners could reach the copper deposits. The mines haven’t operated for decades, but there are still huge piles of this rock available, with some pieces being a couple of feet across. Between being big and being angular, they tend to lock together so that the slope doesn’t erode or collapse. A lot of the roads around here have substantial amounts of rip rap placed, and it seems to hold really well.

[2] This is similar to the behavior of the Mullein that was previously posted here, when it had a massive population explosion in the pine plantation out back after the lumber company came through and thinned the trees, allowing light to get down to the forest floor again.

2 Responses
  1. July 28, 2020

    Thanks for keeping up your blog, Tim. I always enjoy it.

    A book of local flowers is such a great idea! I love the way they organized it to, designed for the flower-watcher.

    I would have thought that fireweed was a reference to some stingy property of the plant.

  2. July 29, 2020

    Thanks, KT. I always intend to post more frequently, but there are always a lot of distractions.

    The “Blooming Seasons” book is great, it is probably our most useful plant-ID book exactly because it is specific to the area and to the time of year. The author was pretty thorough, too. Our other flower books cover too much of the country (and as a result have too many entries), and are mostly organized weirdly (like the one that is supposedly sorted by color, but puts some of the purple flowers with the pink flowers, while other purple flowers go with the blue ones).

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