What Happens to Solomon’s Plume Tops

by Carl Strang

Smilacina racemosa, the feathery false Solomon’s seal or feathery Solomon’s plume, is a woodland perennial herb that vanishes before we can seek it in the winter botany season. So, what becomes of its tops? This is a plant that encloses its seeds in berries, junk food for naïve first-time migrant birds (the berries are an attractive red color, but are lacking in nutritive value: White and Stiles 1985, Ecology 66:303-307). Since most of these migrants pass through in September, the tops remain upright at least that late.

A Solomon’s plume plant with berries on display

A Solomon’s plume plant with berries on display

Very quickly, though, senescence begins.

The berries are gone, and the leaves rapidly are browning.

The berries are gone, and the leaves rapidly are browning.

By late autumn the leaves will be gone, and the stalks collapsed and buried in the new load of leaf litter. This is a perennial, and the roots will grow a new top next year.

Fruits of the Season

by Carl Strang

The season draws down toward winter, and the photosynthetic labors of the myriad plants are being expressed through the product of their fruits. Plants can’t spread their seeds around without help, though, and this is a good time to compare and contrast the different ways in which evolution has diversified the seed dispersal process. Some use the wind, and this haphazard distribution method only succeeds if lots and lots of seeds are released.

White snakeroot seeds, parachutes unfurled and waiting to be carried away.

White snakeroot seeds, parachutes unfurled and waiting to be carried away.

Wrapping the seeds in fruits that animals can eat is more economical in the sense of being more targeted. I often have wondered if purple or black fruits low to the ground specifically are aimed at mammalian dispersers, whose narrowly defined habitual routing increases the chance that a seed will land in a suitable habitat. As a result, fewer seeds need be produced.

An example is the carrion flower, a thornless Smilax.

An example is the carrion flower, a thornless Smilax.

Carrion flower fruit cluster

Carrion flower fruit cluster

And then there are the plants that use us for transport, not because we eat the fruits but because we provide traveling surfaces the seeds can stick to.

My all-time least favorite example is stickseed, which I do my best to step around.

My all-time least favorite example is stickseed, which I do my best to step around.

All these methods work, of course, otherwise the plants would have vanished long ago.

Garden Bloodroot Disperses

by Carl Strang

I have planted 3 bloodroots in my shaded garden flowerbed. They are the earliest of my native plants to flower each year, and all have multiplied by root expansion. This year they demonstrated their fecundity in a different way. A fourth plant, growing several feet beyond the nearest established bloodroot, has matured enough to flower.

I had noticed leaves here the past year or two.

I would not have planted a bloodroot up against the edging like this, but it’s not an unreasonable place for an ant colony to do so. Ants are the main dispersers of bloodroot seeds, as well as those of a number of other plant species that bloom in our forests in early spring. Their seeds tempt the ants with fatty outgrowths called elaiosomes. Using these as handles, ants carry them to their nests. After consuming the elaiosomes the ants discard the useless (to them) seeds, having conveniently (for the plant) carried them into the protective soil.

This is very satisfying. Mine is not a hands-off garden. I have to work diligently, for example, to constrain the zig-zag goldenrods. But in this case I welcome the ants’ partnership, and look forward to watching the expansion of this newest bloodroot colony.

Honeysuckle Signpost

by Carl Strang

Last week I was walking through the south savanna at Mayslake Forest Preserve when my eye was drawn to this old signpost.

The post once held a sign warning people to stay away from the friary, which was demolished last year.

What struck me was how the post was partly surrounded by a honeysuckle bush.

This vase-like, fanning array of stems is typical of honeysuckles.

No one would have forced their way into the bush to place the sign, so it seems likely that the bush grew up after the sign was in the ground. Furthermore, the sign may be responsible for the bush being there. Honeysuckles disperse with the aid of birds, which eat their berries.

Fruits of amur honeysuckle.

I am guessing that a robin, a catbird or one of the other species that eat these berries, facing south while perched on the sign, ejected the seed which had passed through its digestive tract, planting the bush which ultimately embraced the north side of the signpost.

Mayslake Plant Notes

by Carl Strang

This is the time of year when the prairies and meadows at Mayslake Forest Preserve are spectacular with masses of asters, goldenrods and other prairie plants.

Many plants also are fruiting now. I took a moment to study some fallen ginkgo fruits.

They are about an inch in diameter, and each contains a single seed that fills much of its volume.

I have heard they have an awful smell, so this was one of those rare occasions when I was glad for my nose-plugging allergies. I was reminded of the ginkgo seedling I spotted last year below the friary, half a mile distant on the far side of May’s Lake.

Now that I’ve seen the size of that seed, I am less inclined to think that a bird transported it. Now coyote seems the likely disperser, unless there is a female ginkgo off the preserve that is closer.

The red oaks are producing a lot of acorns this fall.

Mayslake doesn’t have many red oaks, but the large ones all seem to have plenty of acorns beneath them.

This may be a regional mast year for them, as I have noticed the same production across the county at Herrick Lake Forest Preserve.

Needless to say, squirrels like mast years.

More Mayslake Fruits

by Carl Strang

Earlier I featured several plants at Mayslake Forest Preserve that produce fruits timed to coincide with the fall migration of berry-eating birds. This mutualistic interaction for the most part benefits the birds, through nutritional provisioning, while the plants get their seeds dispersed. Today I want to feature some outliers to this pattern. Let’s start with Solomon’s plume, also known as false Solomon’s seal.

Solomon's plume fruit b

Like many fall fruits, these advertise themselves to birds with a bright red color. When analyzed, however, the berries proved to be junk food, or perhaps are more accurately described as food mimics (White and Stiles 1985, Ecology 66:303-307). The plants save their energy, investing no nutritional value in these fruits. The ruse works, apparently, by exploiting the naïve instinctive response of first-time autumn migrants, the young of the year. A little different from this is the offering of the European highbush cranberry.

European highbush cranberry fruit b

Another study (Witmer 2001, Ecology 82:3120-3130) showed that the nutritional value of these berries becomes available only when they are consumed along with a significant protein source. I was impressed to learn that, like the waxwings native to the shrub’s European home, our North American cedar waxwings ignore these tempting berries until spring, when cottonwoods or other poplars are flowering. Then the birds consume the berries along with cottonwood catkins, protein in the pollen providing access to the berries’ nutritional value.

Common buckthorn fruit b

These black berries are common buckthorn fruits. They generally are ignored by birds until late winter when, apparently, the better quality foods have been depleted. Then, robins and waxwings consume them, unfortunately dispersing the seeds throughout our woodlands. Buckthorns leaf out early and lose their leaves late, casting a shade so dense that no other plants can grow beneath them. This is why these Eurasian shrubs must be removed at the beginning of woodland restoration projects. A final fruit is of no interest to birds.

Buckeye fruit 2b

Ohio buckeyes in fact are largely ignored by animals generally. This opens the possibility that, like other trees I discussed earlier, buckeyes may have been dispersed by now-extinct mastodons and other large herbivores.

Mastodons? We Don’t Need No Stinkin’ Mastodons!

by Carl Strang

In one of this spring’s earlier posts  I mentioned the difficulty Kentucky coffee trees have in getting dispersed, now that mastodons and other herbivorous megafauna no longer are around to facilitate their transport. Recently, though, I noticed that the grove of Kentucky coffee trees at Mayslake Forest Preserve has quite a few saplings coming up around its periphery.

Kentucky coffee tree leaves 2b

Most of this photo is occupied by a single, bipinnately compound leaf extending upper left to bottom right and out of the frame. Though dispersal distance clearly is more limited than it would have been in the gut of a mastodon, these trees are reproducing just fine, thank you very much.

Owl Nest Postscript

by Carl Strang

Mayslake’s great horned owls lost their nest  when a March storm broke off their tree right at the nest cavity. I was passing that tree in late May, and was interested to see a spot of green up there.

GM owl nest 2b

It’s a garlic mustard seedling, growing rapidly in its well-lit location, its roots penetrating the rotten wood high above the ground. A moment’s thought produced a couple possible explanations of how the seed got there. Garlic mustard produces seeds prolifically, but they are not wind borne or explosively expelled. In areas where the species is invading, I often have seen the first plants germinating beside animal trails. They are not particularly sticky or burry, but they are small and so can cling to the feet of animals to be transported for a short distance.

GM owl nest 1b

The seed may have been carried into that cavity by a climbing raccoon, squirrel or mouse. It may have gotten there on one of the parent owls’ feet. It may have been sticking to a prey animal they carried there to feed one of their doomed young. However it got there, the garlic mustard seed got its best chance to grow when the top of the tree broke off and exposed the floor of the former nest cavity to the sun.

Seeds on Snow

By Carl Strang

 

There is a magnificent paper birch near the entrance of Mayslake Hall which has managed to evade the bronze birch borers long enough to become robust and beautiful.

 

paper-birch-2b

 

Yesterday I noticed that the birch had dropped seeds onto the snow.

 

paper-birch-seeds-2b

 

For a moment I was a little surprised that there were any seeds left. A couple weeks ago that tree was filled with goldfinches, juncos and pine siskins pigging out on seeds they were digging out of the tree’s cones. Obviously they missed some, for the snow was covered with yellow-brown seeds and shed cone scales.

 

paper-birch-1b

 

After taking some photos, I thought about the timing. Now, with leaves dropped from deciduous trees, the little winged seeds have their best chance of being carried away on the wind. Furthermore, if there happens to be snow on the ground, the wind can further push the seeds, increasing the area over which they are spread. This might improve the possibility that some will find suitable places to grow.

 

That thought brought out a memory, of a presentation decades ago at an Ecological Society meeting. Someone had studied Queen Anne’s lace and found that its seeds are contained within the closed umbrella of its flower/fruit support struts.

 

qa-lace-closed-b

 

The struts remain closed when the air’s humidity is high, but open as humidity drops, so that seeds are released in the dry air of winter when there is a good chance the ground will be snow-covered, allowing the seeds to be wind dispersed over a smooth surface.

 

qa-lace-open-2b

 

Later during my lunchtime walk I found some Queen Anne’s lace, and sure enough, though some were closed, others had opened and begun to drop their seeds onto the snow.

 

qa-lace-and-unknown-seeds-2b

%d bloggers like this: