The Search for Sisyrinchium sarmentosum

A fairly light-colored blue-eyed grass, but is it Sisyrinchium sarmentosum

A fairly light-colored blue-eyed grass, with rounded tepals, but is it Sisyrinchium sarmentosum? Note the winged stems and fairly narrow tepals.

According to the literature, Sisyrinchium sarmentosum (pale blue-eyed grass) is a rare species found only in a small area of the Cascades in southern Washington and northwestern Oregon near the Columbia Gorge. The Forest Service has been looking for more potential sites and has found several apparent populations farther south than the Columbia Gorge. Jenny Lippert, Willamette National Forest botanist, asked me to come along with her to a couple of these sites to take photographs, so on Wednesday, July 2, Sabine and I accompanied her to several moist meadow areas in Linn and Marion counties. Our first stop was Little Pigeon Prairie. It took us a little while to spot the blue-eyed grass because it was cloudy and before noon, and they don’t like to open up until the afternoon (I’m not much of a morning person myself!). As we headed to another nearby meadow just outside the large wetland of nearby Pigeon Prairie, suddenly the sun came out and so did the little blue stars of Sisyrinchium. It also went from cool to warm and humid very quickly—a fact that almost resulted in a major calamity for Sabine. While taking off her outer fleece, she had to take off her binoculars, which were on a harness. Before leaving the meadow, she realized the binoculars were missing but couldn’t remember where she’d taken them off and couldn’t find them anywhere. It was only after more or less giving up and heading out that she stumbled upon them again. What a relief! It’s a lesson for all us to mark all our equipment with brightly colored tape or paint—I have now put bright red tape on both my GPS and my oft-dropped lens cap.

blue-eyed grass

Shortly after the clouds lifted, the blue-eyed grass flowers began to open for the day.

After reading up on the differences between Sisyrinchium sarmentosum and the common S. idahoense (Idaho blue-eyed grass), it seems to me that the real challenge may be actually separating these two species. There are a number of characteristics used to identify S. sarmentosum. The main ones I can figure out are that it has pale blue tepals that are rounded on the outside and less than 3 times as long as they are wide, wingless stems (according to some but not all sources), and wrinkled seeds. Different authorities emphasize different characteristics. The trouble is, S. idahoense is a very variable species, with 2 varieties in Oregon, and many of those characteristics mentioned for S. sarmentosum can also be found in populations of S. idahoense. Flora of North America (FNA) says rather confidently, “The pale blue flowers with rounded apices on the outer tepals set this species apart from others in the region.” How pale is pale? The blue-eyed grass we saw at Pigeon Prairie seemed fairly light, with only a few darker ones here and there. Would the dark ones be S. idahoense mixed in or natural variety in S. sarmentosum? I looked at the few photos of on the web, and they seem much lighter than what we saw, but then again, the images weren’t of the highest quality and could be overexposed. Color in photos certainly can’t be relied on. Since that trip I’ve been out several times and seen S. idahoense in bloom twice much farther south, and many of the flowers appeared to be the same color as those at Pigeon Prairie and Bruno Meadows. I even found a pure white one! The rounded apices were mostly evident at Pigeon Prairie, but FNA says S. idahoense can have rounded tepals, and I saw some in S. idahoense on my later trips. A paper on Sisyrinchium written by Douglass Henderson in 1976 stated that one of the most consistent differences he found was the ratio of the length to the width of the tepals, with S. sarmentosum having relatively wider tepals than those of S. idahoense. The photos from Washington populations do show chubbier petals than any I’ve seen. There are still no ripe seeds to check, but I have my doubts as to how helpful those will be. For the moment, I’m still not convinced that the meadows we surveyed had the real Sisyrinchium sarmentosum, but whatever they were, they were still beautiful, and I know Sabine and I enjoyed our outing.

Beargrass at Pigeon Prairie

A beautiful display of beargrass (Xerophyllum tenax) at Pigeon Prairie

There were other flowers of interest in addition to the blue-eyed grass. The beargrass (Xerophyllum tenax) was in full bloom along the edges of the meadow at Pigeon Prairie and along the roads. I’m guessing it will be an awesome show once again on nearby but much higher elevation Coffin and Bachelor mountains this month (see NARGS Campout Day 2: Coffin Mountain for a look at last year’s great display of beargrass). We also got to see the common arrowleaf groundsel (Senecio triangularis) growing alongside its cousin, streambank butterweed (Packera pseudaurea, formerly Senecio pseudaureus). Althought the former is common throughout the Western Cascades, the latter is one I only see in wetlands in the northern half. It does occur much farther south but mainly east of the Cascades.

Checkermallow (Sidalcea malviflora) Left

Checkermallow (Sidalcea malviflora?): pistillate (female only) inflorescence on the left, regular inflorescence on the right.

At the meadow where we found blue-eyed grass near the Bruno Meadows wetland, our second stop, we also saw some checkermallow (Sidalcea sp.). I was hoping these had started to bloom because I’m still struggling with this genus, and this is a specialty of Jenny’s. According to the Oregon Flora Project Atlas, several people had thought they’d seen Sidalcea cusickii (that was my original guess, but I’m taking that back now that I’ve seen more S. cusickii. Its wide-based sepal lobes are pretty distinctive.), and others had collected what had been determined to be S. oregana ssp. oregana. So Jenny’s conclusion that it was a subspecies of S. malviflora was either a third opinion, or perhaps it was yet another species in the same area. More confusion! Whatever the case, one of the really interesting things about checkermallows (and perhaps a contributor to the ID confusion) is that they may have inflorescences that are perfect (flowers have male and female parts) or they may be solely pistillate (female parts only). The latter look quite different as we were able to see. The pistillate flowers were much smaller, quite a bit darker, and were, of course, lacking the cluster of stamens in the middle. I’m not sure if all checkermallows do this, but I have seen this in the Sidalcea malviflora ssp. virgata that grow on my property. It certainly might make one think they are looking at two different species.

Sheep moths (Hemileuca eglanterina). Male on the left, female on the right on Castilleja miniata.

Sheep moths (Hemileuca eglanterina). Male on the left, female on the right on Castilleja miniata. Sheep moths have highly variable markings, but they are all quite striking.

What distracted me from my usual obsession with flowers were the flying creatures. Along with a number of butterflies, I was thrilled to see not one, not two, but three sheep moths (Hemileuca eglanterina) resting on plants. Usually these large, colorful, day-flying moths are constantly on the wing. Sheep moth caterpillars feed on species in the rose family, and there were plenty of roses as well as hawthorn and other related shrubs. There were two of these moths fairly close to one another. One was larger than the other, and it seemed likely to me that the smaller of the two was a male because he had much wider antennae. I later read that this was true. These help him catch a whiff of the female’s pheromones. Later I spotted another individual sitting on a plant, being accosted by a much smaller meadow fritillary. I was very dismayed that I wasn’t able to photograph the two together before the butterfly flew off. Sabine and I had seen this unusual behavior seven years ago when a female sheep moth was clearly being courted by a very confused checkerspot butterfly, (to see the photo, check out the butterfly photo gallery by clicking here. The photo is near the bottom). Apparently the combination of powerful pheromones and the oversized golden orange body are too much for these smaller, somewhat similarly colored butterflies to resist.

This sheep moth had different markings than the others. I'm guessing it was also a female, based on the fact that a butterfly was attracted to it!

This sheep moth had different markings than the others. I’m guessing it was a female, based on the fact that a butterfly was attracted to it!

One Response to “The Search for Sisyrinchium sarmentosum”

  • I have found 2 Sisyrinchium spp along the coast (identified for me):
    Sisyrinchium californicum
    Sisyrinchium bellum

    And, occasionally I have found them on the east side of the coast range. They where inadvertent finds. So, it seems to me that only S sarmentosum is rare.

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