Flower colors

musings on the palette of summer

Just before the summer solstice, a little group of friends walked out onto Cowee Meadow. Although it was raining in town, out there, the sun was shining. The meadows were a blaze of color: pink shooting stars, yellow buttercups, and blue lupines covered acres with floral glory. While those species were dominant in the meadows, we counted over sixty species of flowers on our walk (not counting grasses and sedges). We did include the irises, which were just starting to bloom; in another week or two, irises will be the main show.

Among all the blue lupines were three or four individuals with pink flowers, and we’ve sometimes seen very pale shooting stars. On the upper beach, there’s the usual blue-flowered oysterplant, with a few white-flowered individuals—and even one plant that apparently made both blue and white flowers. Rare white-flowered geraniums and beach peas are also reported among the usual purplish ones, and some chocolate lilies have yellow (instead of brown) flowers. That made us wonder about the fate of these mutants—do they get visited by insects or are they reproductive failures?

While cogitating about flower color, we also commented that white flowers seem to characterize more of our native, local flowering species than any other color, although many of those white flowers are small and inconspicuous. There’s a fair number of species with blue/purple, yellow, or pink flowers, but red, orange, and green flowers are rare. However, white may not predominate in our alpine zones–It might be interesting to compare the frequency distribution of floral colors in different habitats and contemplate possible relationships with the available pollinator fauna (or other factors).

A common white flower on the Cowee Meadow trail is dwarf dogwood (bunchberry). It’s so common and familiar that it often escapes notice! That ‘flower’ is really an inflorescence composed of four whitish bracts surrounding a tight central cluster of actual flowers. There were many other things to look at on that hike, so I didn’t take time to inspect those dogwood inflorescences closely.

Photo by Kerry Howard

However, a few days earlier, I had done so on the Eaglecrest Lower Loop—higher in elevation, so the dogwoods were then less advanced and I could observe the seasonal progression of floral development. Some dogwood inflorescences were just opening and the bracts were small and green; the floral buds in the center were dark and tightly closed over the male and female parts inside. On more advanced inflorescences, the bracts were bigger and greenish-white, while the floral buds were still dark and closed. Then the bracts get bigger and whiter, and by the time they are fully mature, the floral buds are starting to open, exposing the sex organs to visiting insects. The flowers ultimately can open by themselves, but studies have shown than an insect visit can trigger floral opening and an explosive release of pollen. In either case, stamens catapult pollen vertically for several centimeters at very high speed, onto an insect or into the breezes. The pollen grains are not sticky, so high-speed release is thought to be necessary for adhering the pollen to an insect. Whether by wind or by insect transport, pollination is only successful when pollen arrives from a different dogwood individual, because this species is self-incompatible. After pollen is ejected, the pollen-capturing surface of the stigma increases, ready to receive incoming pollen. However, fruit-set generally seems to be low.

Another white-flowered plant was blooming profusely in the meadow along the Lower Loop trail: three-leaf goldthread.  This flower looks nothing like the flower of the related fern-leaf goldthread that mostly grows in the forest. The flower is comprised of several white sepals surrounding the sex organs and five (sometimes six) tiny golden trumpets that are modified petals offering nectar to visiting insects. Although I saw no insects visiting a group of open flowers, I watched a small fly working assiduously for several minutes, trying to gain entry into an almost-open bud.

There must be good stories behind the evolution of flower colors and shapes; I wish I knew them!

Cowee Meadows

a May expedition finds flowers and toadlets

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Photo by Deana Barajas

Several things combined, recently, to bring me a strong wave of nostalgia for the Midwest. I love the oak trees—their varied forms and leaf shapes and acorns. On top of that, my brother in Wisconsin regales me with tales and pictures of the birds that throng his feeders—orioles, goldfinches, rose-breasted grosbeaks, catbirds, and more—species that I’ve not seen for a long time. Then one of my old post-docs, in Chicago, wrote to me about all the spring flowers that grace the woodland floors—Dutchman’s breeches, bloodroot, spring beauty… Aaahh, I do miss all that!

However, on the last weekend in May, a bunch of regular Saturday hikers went out to Cowee Meadows. On the way down the trail, we enjoyed the many bog laurels and bog rosemary flowers in the muskeg, and we stopped to inspect the young bracken ferns for nectaries. Cowee Meadows is a place I like to visit several times as spring becomes summer, to see the seasonal development of the flower show. A couple of weeks ago, there were a few shooting stars, some buttercups and marsh marigolds, but little else. But now, the meadows were awash in color: lots of yellow buttercups, shooting stars in all shades of pink, joined now by tall blue lupines. Hidden under the taller plants were violets, starflowers, and the coming chocolate lilies. Even without the famous irises and the banks of roses, which will bloom in a week or two, this is a spectacular sight—hard to beat! Carpets of strawberry flowers out near the river weren’t bad, either, even though I never get there in time to harvest any of the fruits. Nostalgic feelings were successfully subdued.

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Photo by Louise Ketcheson

One of the most common plants in these meadows is the shrub called sweetgale (Myrica gale). It is very aromatic, and the nodules on the roots fix atmospheric nitrogen into a form usable by vegetation. The books say that sweetgale is typically dioecious—male and female on separate shrubs, but occasionally hermaphroditic—both sexes on one plant. Yet the shrubs all looked the same to me; where is the other sex? Then I read that, for unknown reasons, sweetgale males commonly outnumber the females by a big margin. So the many shrubs we see bearing small cone-like structures are presumably males. But if so, what do the females look like? Two field guides and a few official floras were no help at all; if they illustrated any flowering parts, it was the typical cones, and the verbal descriptions were unhelpful. Finally I discovered a website (thank you, Minnesota) that illustrated both male and female inflorescences.

It turns out that the rare female inflorescences look like small, red tufts along a twig. Knowing a characteristic that is useful in the field, we have now found two stands of female sweetgale shrubs and a few mixed-sex individuals in a population that is overwhelmingly male. Good to have that sorted out!

Another satisfying observation on this hike was seeing tiny toadlets making their way through thick tangles of herbage. I don’t know in which pond or slough they spent their time as tadpoles, but with patience, they can travel quite a distance once they have legs. One of these toadlets was crawling about on the upper beach, which is hardly a suitable place for a growing toad. Although it is tempting to catch them, we must remember that if we have insect repellent on our hands, it can poison them through their skin. And, in any case, it is illegal to hold, transport, and release them. Better to just observe and protect them!

When I got home, there was fun at my bird feeders. When the pushy jay and the big hairy woodpecker aren’t there, chickadees, nuthatches, and juncos use the peanut butter feeders daily. I started watching more closely as the three smaller birds pecked at the peanut butter lumps on the feeder. Peck and gobble, peck-peck and gobble. But the last peck gets a little gobbet that doesn’t disappear into the inside of the bill. A small wad of peanut butter is carried off into the woods, and I’m betting that it goes to a chick.

Ducks, sundews, yellowlegs, and…

dragonflies, gentians, leaf beetles, and a yellowlegs encounter too

On a hot, sunny day, I sat with some friends on a big log, looking across Berners Bay toward Lion’s Head. The tide was out, exposing some big rocks off to one side. A female merganser with four half-grown ducklings cruised around, eventually disappearing behind one of those rocks. Suddenly two of the young ones came hurriedly splashing around to the near side of the rock. Hmmm, something was clearly awry! They then went behind the rock again but soon reappeared, with at least one of their siblings, on one end of the rock. There they all settled down into what a friend once called “a little pile of cuteness”. What caused the commotion and the retreat to the top of the rock? We blamed a seal, whose head surfaced next to the rock, looking intently where the duck family had been.

What about the female merganser? As she drifted between her resting brood and the shore, an eagle swooped down on her from behind. A narrow miss for the eagle, as the duck quickly dove down. An exciting day for the duck family.

We were staying in the Cowee Meadow cabin and found entertainment on our doorstep. A red-breasted sapsucker regularly visited the logs of the cabin walls, peering around at us on the deck, almost as if it were hoping for handouts. Later, a sapsucker went down to the ground by the fire-pit and picked up several woodchips, filling its bill and taking off with them. Why would a woodpecker scavenge chips when it could make its own, and what did it want with them, anyhow?

The front of the cabin was patrolled by a large dragonfly that flew back and forth between the creek on one side and the nearby trees on the other. A sudden flash of blue emerged from the trees and made a grab for the dragon, but I think the jay missed its mark; soon thereafter a large dragon was again patrolling the front of the cabin.

A few days later, still in the hot sun, Parks and Rec went to up to Cropley Lake. Great expanses of meadow were spangled with thousands of small white stars: swamp gentians. This annual plant is probably pollinated by flies (rather than bees), but there has been very little study.

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Swamp gentian. Photo by Bob Armstrong

A little lower down in the meadow vegetation, we found many tiny, white, five-petalled flowers of the round-leaf sundew. These small insectivorous plants were so common in some areas that they almost made a carpet, although not all were flowering. Experimental studies, comparing sundew plants with lots of captured insects to those with few captures, revealed that well-fed sundews grow better and make more flowers. The flowers have no nectaries, so they have little reward for pollinators; they are capable of self-pollination. However, insects, mostly flies, do visit the flowers at times. So flies can be pollinators but they are also prey for this plant. That seems self-defeating! However, they are likely to be different kinds of flies, as shown for the closely related long-leaf sundew.

On a walk out toward Nugget Falls one morning, I noticed that the cottonwood leaves had been severely damaged. So of course I looked more closely, and I found lots of small black larvae of leaf beetles. They had munched up the surface layers of both top and underside of the leaves, leaving nothing but a delicate network of leaf veins. Adults of these leaf beetles overwinter in the leaf litter and lay bunches of eggs in spring. The larvae pass through several molts as they munch and grow; the early stages (called instars) are often colonial, feeding in gangs; later instars are more independent. Some trees had been much harder hit by these beetles than others, but is that because some trees are just more susceptible, less well protected, or because of chance events when female beetles were laying their eggs?

A friend and I walked up to a meadow on the Spaulding trail to see if the long-leaf sundews were flowering yet. No, but we had an exciting time nevertheless. There were fair-sized shorebird footprints in the mud of the drying ponds and a shorebird was calling persistently from the top of a dead pine. As we turned to go, we got dive-bombed from behind—a close pass ruffled my hair. Then a second attack, accompanied, as before, by loud cries. (OK, OK, we are leaving anyhow…). Those greater yellowlegs were clearly defending something important, and at last we saw it (there might have been more, somewhere)—a big, tall chick, still fuzzy and flightless, sneaking through the sedges. So we went quietly on our way, leaving them in peace.

A group of five mallards in female plumage come to my home pond that same day. They foraged all around the edge, nibbling here and there. Then they went over to the bank on the far side and I expected them to climb up and settle down for a nap, which is what usually happens. But this time, the naps were delayed and the birds were almost hidden in the brush. The blueberry bushes started twitching and jumping, and I could see that the birds were reaching up to !!pick blueberries!! They cleaned out the berries on those bushes and finally settled in for a nap. I wonder how they learned that blueberries make fine snacks—so different from their usual fare.

Reluctant spring

…in Cowee Meadows

Early April and, despite some earlier signs of spring, we seemed to be stuck in the middle of a long cold spell—freezing at night and daytime temperatures in the thirties or low forties. All the trails were icy, and it seemed as if I would never get all the ice chipped off my driveway.

A friend who had missed a Parks and Rec hike to Cowee Meadows during a warm spell in March wanted to check out that area. Where P&R hikers had waded ankle-deep in meltwater on the trail, in early April it was all frozen solid. We walked securely over the beaver sloughs and ponds—easy going! The only down-side was a very stiff and cold north wind, with gusts strong enough to send me off-balance occasionally. So we didn’t go out on the beach at all, but just wandered around the meadows to see what we could see. We hid from the wind behind some dense spruces for a comfortable lunch in the sun.

There was plenty of evidence that the horses from the ranch across Cowee Creek had paid their usual visits. They too had taken shelter in the lee of spruce thickets, leaving digested evidence of their sheltered stay.

Bird life was scarce. A woodpecker drummed, but it eluded our sighting. A couple of chickadees flitted by, at the forest edge. A group of nervous mallards fled down the creek well ahead of us. Two ravens performed their classic rolls as they flew overhead.

A solitary, hapless robin poked along the fringe of a frozen pool, where the sun had loosened the ice along the edges. There was little there to feed on; maybe it was getting a drink. In fact, there’s not much for robins to eat when the weather is like this—some invertebrates on the beaches, perhaps, and a few frozen berries in the woods; I wonder how they manage to survive.

Two little sparrows, buffeted by the winds, dove into the shelter of bent-over dead grasses. From their pale brown backs, I guessed that they were savanna sparrows, which frequent these meadows. They stayed under cover for some time—smart birds!

Later in the morning, and a little farther on, we came upon a bunch of six crows, all gathered around the edge of a shallow, sun-warmed pool with some remaining ice. They looked like they were drinking: they’d dip the bill into the water, then raise it up and tip it back—which is how many birds drink fluids. But what was so special about this pool, when the creek and some other pools were nearby?

A few green shoots emerged from one small open-water slough. But all the skunk cabbage shoots that had emerged above the surface of the frozen meadow had been blasted by the cold temperatures. It’s not unusual to see frost damage on the tips of skunk cabbage shoots, but out in these meadows, the cold had killed and blackened several inches of new shoots. Not a good start of the season for them.

There were deposits of moose pellets on the snow in several places, clear evidence that moose had been visiting the meadows this winter. Moose have been recorded from Cowee Meadows for several years, as well as a few other places in Juneau, where moose are usually a rarity.

Sweet gale, a wetland shrub, is widespread in these meadows. The volatile oils of this aromatic plant are reported to repel midges and mosquitoes, but moth caterpillars are said to love eating the leaves. Insect damage induces the plant to increase its chemical defenses, reducing further attacks. The volatile oils can also reduce some fungal and bacterial infections. Vertebrate herbivores include beavers and moose; the European mountain hare eats it too, leading me to wonder if our snowshoe hares might do so also. We noted that some of the sweetgale shrubs in the meadow had been browsed, possibly by the visiting moose, but we could not exclude the possibility that ranch horses might have done so.

Sweetgale is an interesting plant in other ways too. It harbors symbiotic bacteria in root nodules; the bacteria fix atmospheric nitrogen, making it accessible to plants. Although some accounts say that male and female flowers are borne on separate plants, in reality, some individual plants have both male and female flowers and, to further confuse the matter of gender identity, sometimes both male and female sex organs are found in the same flower. However, I have not found any information about the factors that might control sex expression in sweetgale. In any case, propagation is said to be primarily by vegetative means, via underground stems called rhizomes, rather than by sexual means and seed production.

Although this excursion to the meadows was very wintery, I just had a cheering report from a friend that ruby-crowned kinglets have arrived! Now spring can get serious.

Solstice at Cowee Meadows

surrounded by abundance

Around the time of the summer solstice, I spent a couple of nights in the Cowee Meadow cabin, along with some friends and my visiting niece. We like the flower show in the meadows. This year, everything was a bit early (after the sunny, hot month of May) and flowering was somewhat past its best, but nevertheless we noted as many species of plants in flower or just past flowering as we found last year (over 75 species, barring grasses and sedges).

The cabin needed some attention, so we swept it out and washed the windows with plain water, having neglected to bring window cleaner. We brought in window screening and duct tape, so we were able to cobble together screens to exclude the flying bugs and thus keep the windows open. As it happened, however, there were astonishingly few mosquitoes and such (what a difference from last year!). Sitting outside for breakfast, lunch, and dinner was very pleasant.

Every day we cruised around the trails, seeing what we could see. A major highlight was the discovery of a sizable patch of RIPE strawberries—just one big patch; the plants all around this site held only green, unripe berries. This discovery caused a significant delay in our progress but there were big smiles all ‘round!

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Photo by Katherine Hocker

These coastal strawberries have a very interesting distribution: they occur naturally along our coasts but different subspecies or varieties also occur on the coasts of Chile and Argentina and, reportedly, in the mountains of Hawaii. The species is thought to have originated in North America, but it was probably carried to South America by migrating birds. There is good evidence that migratory shorebirds can carry seeds and spores of a variety of plants on their long-distance seasonal journeys. Some seeds may stick to feathers and escape being preened off. Strawberries (and other fleshy fruits) are adapted to be eaten by vertebrates, which snack on the fruits and pass the seeds through their guts. Most small birds pass seeds rather quickly, in just a few hours, so viable strawberry seeds travelling all the way from the northern hemisphere across the equator to the southern would require a really quick flight or a long residence time in the gut. I observe, with interest, that the coastal strawberry, Fragaria chiloensis, bears the name of the Chilean island where I spent many happy austral field seasons. Historically, this strawberry was widely used and cultivated in Chile and reportedly was hybridized with another species to create the domestic strawberry.

A small botanical mystery confounded us. We noted that the oysterplants (a.k. oysterleaf) on the upper beach fringe made smaller leaves on the parts of the stems that bore flowers. But on saltbush (a.k.a. orache) plants, flowers were borne on stems with both small and large leaves. Why the difference?

We had a report from later hikers of a sickly bear cub beside the main trail and eventually learned that ADF&G had picked it up. Their investigations failed to reveal any obvious cause of the distress, but clearly the little cub was malnourished and in a very bad way. Nothing could be done to save it, and it was a public safety concern to leave the cub where it was as long as the mother was nearby, so it was euthanized. Some observers later saw a female with one cub and thought that the family of the dying cub had moved on.

Along Cowee Creek a doe with two fawns come out of the woods to the sand bars. The doe was limping from a wound on a hind leg, but she was able to lead her fawns back into the thickets when she detected us a hundred yards upstream.

The meadows were popping with savanna sparrows, including lots of recent fledglings. Lincoln sparrows burbled their complex song along the shrubby edges, maybe contemplating a second brood. As we sat on the beach for a while, a male belted kingfisher came over our heads and landed on a big rock partly exposed by a low tide. Presently, he dove and came up with a long, thin fish. Then he headed overland toward an upstream part of the creek. The next day, we were walking up along the creek and heard a group of kingfishers raising a ruckus. We surmised that the chicks had fledged and were begging, but they all went around a bend of the creek and out of sight before we could be sure.

We watched dragonflies laying eggs: the females repeatedly dipped down to touch the end of the abdomen to the chosen substrate. One species dropped her eggs into open water, while another, larger one (a blue darner, I think) chose to put her eggs in decaying wood.

The wonderfully long days of solstice time gave us lots of time to wander about, including a stroll out to the beach in the evening to watch the sun setting—and anything else that came our way.

Solstice in the sun

spotlighting a wild flower show

It had rained, just a little, during the night, so the wet grass soaked our britches as we waded through it. But for once, these Juneau-ites didn’t whine about the wet—it felt really good! The outdoor temperatures the day before had reached into the seventies and the little cabin in Cowee Meadows was a heat collector. There was no cross-ventilation in the cabin unless we admitted hordes of hungry mosquitoes through the unscreened windows—a choice we were unwilling to accept. For real Juneau folks, this was a heat wave! The Down-Southers may laugh, but it was enough to make us a bit wilted.

So we waded happily through the wet grass, in search of nothing in particular and anything in general, and we found lots of things of interest. We brought to bear a diversity of eyes and mind’s eyes, which made our explorations very productive and more fun; one person could never have seen quite so many things. Here is a sampling:

We stood surrounded by acres of purple and blue iris and lupine, with patches of yellow buttercups. A few tall white cow parsnips and tufts of lady fern added contrast and texture. But if we looked more closely, there were dozens of other flowering species in bloom: roses on the raised berms, shooting stars fading, yellow pond lilies, silverweed, and on and on; the list grew very long. Out along the beach were arrowgrass, beach greens, milkwort, and goosetongue. In fact, when we tallied up all the kinds of flowers we saw (excluding grasses and sedges) from the trailhead out to the rocky beach, we had found a grand total of seventy five species of flowers. That’s pretty remarkable, and it indicates just how very rich this area is.

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Wild iris. Photo by Katherine Hocker

Irises came in many shades, ranging from pale blue through royal purple to a gorgeous reddish purple. Beach peas also varied, some with more white, or a deeper pink, or more purple. A big surprise was chocolate lilies that weren’t the usual brownish color (or brown with a few yellow speckles) but rather were entirely yellow (or yellow with a few brown spots). I have to wonder if the color variations affect the behavior of the pollinating insects.

Some species were going to seed, and their ripe fruits or seed pods were diverse in structure and function. Shooting star capsules looked like little red and green easter eggs, sitting in cups. When the capsule dries and splits open, the tiny seeds will be dispersed by the wind. Lupines had been quite well pollinated, but their seed pods were not yet ready to pop open explosively, sending seeds in all directions. Marsh marigold seed heads were like crowns of attractive spikes, each with a little hook, as is common in the buttercup family. Apparently the hook does not contribute to seed dispersal; the seed drops out of the enclosing tissue and floats on the water. We decided that a field guide to fruits and seeds and means of seed dispersal for local plants would be both useful and fun.

Sweetgale shrubs are usually either male or female, although occasionally they are both. Next year’s ‘cones’ were already formed and very small. We noticed that twiglets bearing last year’s female cones were invariably dead, so there seems to be a cost to producing seeds.

The hot weather meant that the insect pollinators were busily visiting flowers. Bumblebees foraged on iris and lupine and beach pea, and their behavior would be worth some detailed attention. The broad, white inflorescences of cow parsnip were covered with foraging flies. Many insects scrobbled over the pollen-rich rose flowers.

It’s the flowers that make these meadows so rich and spectacular, but vertebrate life is also abundant. It was so hot (and rather late into the season for some species) that bird song was at a low level, but I heard a northern yellowthroat singing in the big marsh and warbling vireos in the forest edge. Three kinds of sparrow sang, each in its own habitat.

We visited the colony of beach marmots, who were all down in the cool earth for the day. From the beach berm, we watched a sea otter diving and feeding. A mama seal was accompanied by a small, dark, young one. Whales spouted in the distance, out in Lynn Canal.

Of bears, we saw none. But there was plenty of sign of their presence. Bear-sized trails ran through the thick meadow vegetation. Bear scat decorated the human trails. And one morning we found numerous fresh digs along the upper beach: turned-up moss and soil that hadn’t been there the previous afternoon. Most of the digs were at the bases of rocks, and all seemed to be focused on the roots of species in the carrot family (possibly sea coast angelica and hemlock parsley).