Mountain Plants of the Western Cascades

The west end of the ridge can’t be seen from most of the ridge, but this is where most of the purple milkweed is found.

After my first look at the rocky slope north of Grassy Glade (see Exploring Near Grassy Glade), I was anxious to get back when the milkweed was in bloom (and the weather was better!). On June 11, I drove to Grassy Glade and walked directly to the end of Road 262 to where I could climb down to what I’m now calling “Rabbitbrush Ridge.” Since the thunderstorm drove me away before I was able to make it to the far end of the ridge on my earlier trip, I headed along the ridge to west end rather than poking around down the steep slope. That turned out to be the right thing to do. After finding a few individual plants scattered along the ridge, I was thrilled to come upon a decent-sized population of milkweed blooming in a scree just beyond the north-south dike I had thought marked the end of the ridge. This area was a bit more protected and more gravelly than rocky, so perhaps more to their liking.

Milkweed growing in the loose areas between the rocks along with plentiful Oregon sunshine, ookow, bluefield gilia, and northern buckwheat

My guess is that this species is long-lived, and the number of stalks per plant might give an indication as to how old the plant is or at least how healthy. I think it is important to find out how healthy each population in this area is as a whole and whether it is expanding or contracting. This would help determine what, if any, measures need to be taken to improve the habitat. I had been keeping a count of plants and number of stalks as well as how many plants were blooming. I had a lot more plants to count here now, but the slippery slope meant I did a lot of the counting using my binoculars. From the top of the dike, I could see some way down below the rocks and a few more in a wash right below the dike. I was able to walk down to the highest of these to get a better look at them. Unlike at Grassy Glade, the largest plants I counted had only 10 or 11 stalks, but it was still a much larger population than I had thought from my first, curtailed look at the ridge, so I was delighted.

A hedgerow hairstreak nectaring on northern buckwheat

Many other later-blooming species were also in bloom, including lots of Oregon sunshine (Eriophyllum lanatum), bluefield gilia (Gilia capitata), ookow (Dichelostemma congestum), and northern buckwheat (Eriogonum compositum). These are all great butterfly nectar plants, with multiple small flowers close together in each inflorescence, and although I didn’t see any monarchs, I was happy to watch numerous butterflies enjoying the feast. By far the most abundant were juniper (AKA cedar) hairstreaks, but I saw many others as you can see from the photographs. Some, like the field crescents, were not as willing to sit still for a portrait as others, however. I came home with almost 200 photos of butterflies—my favorite kind of day!

A pale swallowtail enjoying ookow

For some reason, the juniper hairstreaks seem to prefer to nectar together on the same inflorescence, even though many others are available. This northern buckwheat was in the lee of the dike, so perhaps getting out of the wind was the attraction of this plant. A couple of tiny beetles and some ants can also be seen.

Anise swallowtail at Grassy Glade

The real highlight came after I returned from the ridge and went to check the milkweed at Grassy Glade. A couple of pale swallowtails and an anise swallowtail were nectaring on the delicious milkweed flowers. Suddenly, there he was, a gorgeous bright orange male monarch. My first one of the year! He soared around, trying to shoo the swallowtails away, but they also chased him—no one was ready to leave such a wonderful source of sweet nectar without a fight! There were plenty of flowers, so I don’t know why they couldn’t share them. The hairstreaks paid no attention to the larger butterflies and were in turn left alone to enjoy their milkweed flowers. I spent quite some time trying to photograph the monarch as well as the swallowtails. I noticed that he repeatedly returned to the same, seemingly unexceptional stalk of milkweed. Perhaps it had an especially good view of his rivals. Who knows what motivates these amazing creatures. Eventually, somewhat reluctantly, I had to head off. Hopefully, when I return, there’ll be a female monarch as well.

A male monarch on a purple milkweed inflorescence.

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