Beach flowers

A little group of friends strolled out to the ‘island’ at the mouth of Fish Creek. On the berm along the way, we found swathes of pink shooting stars, showy yellow buttercups, and blue lupines—a carpet of color. Out at Cowee Meadows this month, we’ll make an annual pilgrimage to enjoy the fields of wild iris, dotted with chocolate lilies and other flowers, and the banks of wild rose. These flamboyant favorites get most of our attention and appreciation.

It occurred to me, however, that there is an unsung gallery of flowers on beaches and intertidal meadows. These flowers are generally smaller and less showy, but surely they would have some interesting stories to tell. So I did a bit of digging and found surprisingly little detailed information about their life history. In some cases there were contradictory reports, which might mean either that certain reports are simply wrong or that the habits of a species vary from place to place. The bottom line is that there’s plenty of room for some detailed study of pollination, seed dispersal and germination, survivorship and longevity, and all the facets of life history.

In the meantime, here are a few gleanings about some of the seaside flowers—with all the above caveats plus the confusions of alternative scientific and multiple common names (too many to list, in some cases). Most of these species are widespread perennials in the northern hemisphere.

–Sea milkwort (Glaux maritima or Lysimachia maritima): Small, white flowers, pinkish at the base, grow from the junctions of leaves and stem. There are no true petals; the flower is formed of sepals that have taken on the role of advertising for pollinators, presumably small insects, although the flowers might be self-fertile. This species can also reproduce vegetatively, from buds on rhizomes (underground stems). It’s very salt-tolerant; salt glands on leaf surfaces excrete excess salt and the leaves can store fresh water. Milkwort reportedly makes mycorrhizal connections to the roots of other plants. Common on our beaches and other coasts, it also grows in saline habitats in the interior.

Honckenya peploides

–Sea sandwort or seaside sandplant or (locally) beach greens (Honckenya peploides): Clumps of this plant dot upper sandy beaches. Its branches spread over the ground and most reports indicate that it can spread vegetatively, by rhizomes. The flowers have nectar and are said to be honey-scented and pollinated by a variety of insects; I saw several kinds of small flies on the flowers. Some of the flowers have very small white petals, no male parts, and are strictly female. Others have white petals about as long as the sepals; these are hermaphroditic, having both male and female parts. Many of the reports that I read confusingly called these simply ‘male’, but they are self-fertile to some degree, perhaps setting fewer seeds than the fully female flowers.  Females reportedly grow more slowly than hermaphrodites. I recently searched some of our beaches for examples and found three clumps with wide-open female flowers on all the stems and several all-hermaphrodite clumps. I was fascinated to read that clumps with many flowering stems may be comprised of several genotypes but somehow all have the same sex-expression; this needs some elucidation.

–Oysterleaf or oysterplant (Mertensia maritima): Rather showy flowers are pink at first, turning blue; we’ve also seen rare individuals with white flowers. Although they are sometimes visited by insects, they are said to be mostly self-pollinating. The stems spread out on the surface, originating from a big taproot. The fruit is a ‘nutlet’ that can float in sea water for two weeks or more, and the seeds can be dormant for several years.

–beach pea (Lathyrus japonicus): The flower is usually pink or red at first, turning blue-purple at maturity; occasionally, all-white flowers are produced. The flowers absorb UV and nectar guides then become visible. It’s a complex flower that has a lower keel surrounding the sex organs and two spreading wings that are generally paler than the rest of the flower. It’s pollinated by bees, and I expect that (as happens with lupine) the bees have to pry open the flower to do the job. Pollen is shed into the keel and stays viable until the stigma becomes receptive. The seeds float and are viable in saltwater, although the plant can also spread by rhizomes. Bruchid beetles often bore through the hard seed coat, breaking dormancy, which would enhance the germination rate unless the beetle larvae eat too much; wasp parasites that kill the larvae reduce damage and allow good germination. Beach pea (like lupine and other legumes) has root nodules containing Rhizobium bacteria that fix atmospheric nitrogen into a form usable by plants.

–Beach lovage (Ligusticum scoticum): The small, white or pinkish flowers in a cluster on top of the plant can be pollinated by flies and other generalist flower-visiting insects. The plant is tolerant of salt spray. We have observed that bears commonly dig up and eat the root, but the possible effect of this activity on the lovage population is not known. One report suggests that perhaps it can regenerate from root fragments.

–Glasswort or pickle weed or sea asparagus (Salicornia virginica): Hermaphrodite flowers are tiny, in groups of three, sunk in hollows at the stem joints on a spike. They may self-pollinate. This plant is considered to be a perennial but may be annual in some places. In California, it responds to the addition of nitrogen and phosphorous even in estuaries with high nutrient levels. It provides essential habitat near San Francisco for the endangered salt-marsh harvest mouse.

Recent finds along the trail

A stroll across Bridget Cove tide flats in early July brought us to a stand of eelgrass. To our surprise, the eelgrass was dotted with many thousands of fish eggs. We thought this was too late in the season for herring, but a forage-fish expert told me that herring have been known to spawn there in early July. The eggs would need to incubate for about two weeks (at a temperature of eight degrees centigrade) and the embryos of these eggs appeared to be in early stages of development. If we went back a week or so later, they probably would have hatched.

After the recent jökulhlaup, I went to inspect the ‘gooseneck’ area on the lower Mendenhall River, where a sweeping loop in the river has created a narrow peninsula just upstream from Vintage Park. I imagined that the big water coming down would have breached the really narrow part of the peninsula, flowing over the top and eroding at least an overflow channel. But no! There is indeed some new erosion of the bank on the upstream side. On top, trees now lean downstream, their roots tipping up and making large cracks in the soil; they will probably fall rather soon, reducing the top of the peninsula to just a couple of feet in width. Something to keep our eyes on!

Just on the other side of Cropley Lake, in a wet area, is a stand of pale yellow flowers. This is a species of fireweed called yellow fireweed or sometimes called yellow willowherb (Epilobium luteum). The familiar pink flowers of the usual fireweed (formerly a species of Epilobium but now reclassified in a separate genus, Chamaenerion) are evident all over town, but the yellow one is much rarer. We’ve seen small numbers of this in only a few places around here. It can propagate vegetatively, so once a plant gets established from seed, it can spread locally if the habitat is suitable. And by the way, why is the pollen of the pink fireweed sometimes blue-green?

Another familiar local plant is known as goatsbeard (Aruncus dioicus). This species is dioecious, bearing male and female flowers on different individuals. On a recent stroll up Perseverance Trail, we looked more closely at the narrow flowering tassels. Indeed, just as expected, males and females were distinguishable. However, we were interested to see that in a very few male plants, a small number of seed pods were developing on some of the tassels. I recall that some other reportedly dioecious plant species have similar transgender issues at least upon occasion. Because the female plants were well past flowering and had well-developed seed pods, we could not tell if any of them had once sported male parts.

On Gold Creek, a female harlequin duck was foraging, dipping and diving among the rocks. We enjoyed watching her skillful maneuvers, swimming upstream underwater, skittering rapidly on the surface of a broad, flat rapid, doing balanced skids on wet rocks, and ferrying across the fast chutes just like a kayaker or a canoeist would do. Humans may have learned this technique, long ago, from the ducks.

A friend reported a dipper nest in the spillway on Gold Creek, so I went to look. Sure enough, in a big crack in the concrete was a pile of moss with an opening through which I could see movement. Mama dipper was either incubating eggs or brooding chicks, while Papa was on guard on a boulder nearby. Later, I looked again, and now the adults were both outside, feeding three or four small, piping nestlings. Big loads of caddisfly larvae and other goodies went down the begging mouths. Very satisfying to observers, as well!

One day we walked on the sand flats of Eagle River along the Boy Scout Trail. There were small footprints in the sand, looking a bit like a baby’s foot but with five claw marks well ahead of the pad. Hmmmm, probably a porcupine. And presently we saw the perpetrator, busily nipping of the ends of beach greens (a.k.a. seabeach sandwort; Honkenya peploides) shoots. After some minutes, the critter bustled off toward the woods, and we went to look at the nibbled shoots. It had ignored the shoots with seed pods and seemed to have concentrated on the shoots with flowers.

This area of sand flats has many clumps of beach greens, whose shoots sprawl out in all directions. In one portion of this plant colony, most of the clumps had been rolled up from one side…the long shoots on that side were flopped over the ones on the other side, consistently in the same direction. We know from reports of other observers that porcupines sometimes roll up outdoor carpets and lick what is underneath. Could these plants reflect similar behavior? If so, what are the animals getting?

Thanks to Darcie Neff for information and references.