Surveying Milkweed at “Maple Creek Meadow”

This is the same view across the meadow, with the same milkweed and rabbitbrush, as I posted last year. You can see an open, rocky slope on the near ridge. I visited it a few days later. Grassy Glade is nearby on that ridge but can’t be seen from here. Unfortunately, the clouds never really broke, so we couldn’t see the view of Diamond Peak.

Last July, I discovered a new site for purple milkweed (Asclepias cordifolia) in the Rigdon area (see Another New Milkweed and Monarch Site!) and dubbed it “Maple Creek Meadow” since the nearest named feature is Maple Creek. I had been looking forward to getting an earlier look at it but wanted to wait until the milkweed had at least emerged. Since I had seen it coming up in some of the nearby sites, John Koenig and I decided to head up there on May 11. Knowing where I was going and how great a place it is, I found the boring, 1.7-mile walk up the bermed-off Road 217 much more pleasant than I did last year when I was wondering all the while if it would be worth it. We had hoped the morning clouds would burn off, but we were under clouds most of the day, so we didn’t get to see many butterflies.

This emerging purple milkweed plant has at least one side branch, apparently unusual in this species.

We spotted the purplish plants of emerging milkweed very quickly. We decided to do an informal count on the quarry side of the road that cuts through the area. The loose, crumbly rock made this more difficult than in the other sites, but there were many plants fairly close together. In fact, we counted over 70 plants, including many small ones without developing inflorescences; presumably, these are much younger plants. Our largest plant had over 20 stalks.

After a lunch break, we decided to head down this dead-end road to check out some small openings down the hill. It had been logged a while back and was mostly young Ponderosa pine forest, but the understory was pretty enough with lots of graceful California fescue (Festuca californica). We were looking for an opening just below the main meadow but it had looked steep by the edge of the road. We found a couple of smaller openings, one of which had quite a bit of ground rose (Rosa spithamea), the pretty rose that seems uncommon except in the Rigdon area.

On the quarry side of the road, the rocks are quite crumbly, and the soil is tinged with orange.

When we reached the end of this short road, we bushwhacked up the hill, following the aerial images on our electronic devices. Unfortunately, there was quite a bit of poison oak in the woods here, so we couldn’t beeline for the opening. While avoiding the poison oak, we were surprised to come upon a spring with newly emerging elk clover (Aralia californica). We weren’t sure what it was at first, as it wasn’t anywhere near as tall as full-grown plants. But last year’s exceptionally long stalks lying on the ground confirmed it was, in fact, Aralia. I’m not sure I’ve ever seen it in this area before.

Spring phacelia coming into bloom

When we finally emerged into the opening we could see through the trees to the main meadow. I felt silly having gone on such a circuitous route, but we would have missed the spring had we realized there was a much easier way to get there. There wasn’t much of interest in this side opening, mainly some pretty blue-eyed Mary species (Collinsia rattanii and C. parviflora) in bloom, but there was a grand old madrone (Arbutus menziesii) in the stretch of large trees that separated the opening from the main meadow.

We came out of the trees near the base of the steep slope. The main meadow is quite rocky with stretches of loose scree in between. As we climbed part way up the hill across these gravelly stretches, I commented that this was the ideal habitat for spring phacelia (Phacelia verna). John had spotted it on our recent trip to the equally rocky slope of Coal Creek Bluff (see First Flowers at Coal Creek Bluff) but forgot to let me know until he got home, so it was on my mind. This sweet little annual is endemic to a limited area of the Western Cascades of southern Lane County and Douglas County, so any sighting is important. No sooner had I started looking for it then it appeared! It was just starting to flower. The more we looked, the more we found. With several acres of this habitat, we figured there would be a large population, but we never spotted any the rest of the day, in spite of looking for it carefully. There’s just no telling, sometimes, why a plant seems to like one place and not another that seems identical to our eyes. Perhaps the soil is different, or there is more or less sun or moisture that we can’t discern.

The pale spot in the middle of this plant was covered up by a clod of dirt and one of last year’s stalks. Even the inflorescence wasn’t purple where it had been covered up.

When we got higher up the slope, we started to spot more milkweed. Counting it on this steep slope would be a daunting task, so we just noted where they were—clustered along the top and bottom of the meadow—and counted the number of stalks of the largest ones. We found several with over 20 stalks. Purple milkweed plants emerge quite dark, tinged with purple, later becoming a lovely glaucous blue-green. Upon removing a clump of dirt and dead material lying across part of one plant, I was surprised to find almost a complete lack of color where the leaves and inflorescence were covered up. I imagine the anthocyanins that cause the coloration protect the plant as it emerges.

John exploring the west end of the slope

We headed over to the far western end, which is partly separated from the main meadow by stands of conifers. There was a little moisture left in a seepy area and a nice show of rosy plectritis (Plectritis congesta) and California mistmaiden (Romanzoffia californica). As we climbed up a rock outcrop, I pointed out that none of the milkweed was actually on the outcrops—this was debunked almost immediately by three plants growing on the same outcrop. We’ve been trying hard to figure out what the best habitat is for the purple milkweed, but it seems to be different from place to place. If only we could ask the plants themselves!

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