Ironweed: Fall and Summer

I spend much of July and August — and half of September — walking in the Eliza Howell Park prairie wildflower field, admiring the flowers and watching the insects.

Now, in mid-October, the flowers are in seed and the field is a feeding site for several species of migrating sparrows. Recently I stopped by to take a look at a favorite Ironweed, a flower on the regular route in the summer. I was seeking a close look at the seeds.

This particular plant is over 8 feet tall, the tallest flower in the field. Though the seeds are attractive, they don’t command the kind of attention the intensely colored flowers do during their month-long blooming time. This picture was taken in August.

In the summer I regularly check the scattered Ironweeds for butterflies and frequently find them. The flowers are grouped near the top of the tall plants so the nectaring butterflies are easy to spot from some distance away. And the size makes it possible to get pictures of butterflies with the sky as background

This picture of a Monarch was taken in August. The next one, of a somewhat beat-up Tiger Swallowtail, was taken in July.

Ironweed is a native perennial wildflower that is sometimes grown in gardens, where tall upright plants are wanted. It spreads by seeds, dispersed by wind.

The name “itonwood” comes from the tough stem. Praying Mantis eggs remain in the egg case over winter, hatching in the spring, and the females often select a sturdy plant for laying their eggs. In September I found that one had, understandably, selected an Ironwood plant. This case seems to be doing well so far.

I might not notice the new growth that will emerge next spring until it gets to be several feet tall in June. But I will definitely follow it through the Summer and into the Fall

Fall Foliage: October Is the Month

Over the years I have often heard individuals in this part of the country say that Fall is their favorite season. It is a totally understandable preference. For nature walkers and nature admirers, the weather and the foliage alone are enough to lift the spirits many a day.

To observe fall foliage in Detroit’s Eliza Howell Park, October is definitely the month. Early on dewy and sunny mornings, the view from my birding path can even take my attention away from migrating birds.

As a way of focusing closely on the color changes, I have been taking pictures of the same trees regularly as October progresses. The first picture of this Sugar Maple was taken on October 5; the second on October 11.

I am in the practice of taking a picture several times every month looking upstream from the footbridge over the Rouge River. The view changes every day in October, even if only a little.

These are from October 1 and October 11.

Not all tree species are on the same schedule. Yellow-bud Hickory (AKA Bitternut Hickory) is among the earlier ones. It was nearing its golden peak on October 10 when this picture was taken.

The Pin Oak, on the other hand, has only only recently begun the annual transformation (this picture is from October 14). I will be following it carefully in the next two weeks.

The Sugar Maple above is fully red. Here is another tree of the same species that still has a long way to go. I have already been following this one for two weeks as it very slowly turns red, starting at the top,

It has been difficult selecting the photos for this report because I have been watching – and documenting – a variety of different deciduous trees, too many to include here.

In addition, the leaves of some other plants are also striking this month. This grass is one example.

Michigan is a great state for fall foliage and, especially in Detroit / Southeastern Michigan, October is the month to enjoy it.

Milkweed Seeds: Ready to Blow in the Wind

The seed pods of the Common Milkweed, developing over many weeks, are now starting to open in Eliza Howell Park.

Each seed is attached to a silky coma, a “parachute,” which facilitates dispersal by the wind.

The pods split open and the seeds separate, starting at the end of the pod. The brown color indicates that the seeds are mature or ripe, useful information for anyone wanting to collect milkweed seeds for a butterfly garden.

They don’t all ripen at the same time, but these are ready to fly.

The parachute look is evident in a close up view.

Milkweed spreads by rhizomes (roots or underground runners) as well as by seeds. The rhizomes account for the fact that milkweed is often found in colonies, the milkweed patches that I regularly visit in the park. Seeds are designed to start plants in new locations at a distance removed and wind dispersal is perfect for that.

The about-to-be-dispersed seeds are asking to be photographed on a dewy morning.

Milkweed, once best known as an aggressive weed that is difficulte to eradicate from crops, is now widely known as the plant that the marvelous Monarch butterfly depends on.

Common Milkweed attracts many other insects in addition to butterfies. When it is blooming, the milkweed patch is a great place to watch various pollinators. And now that the seeds are ripening, I am watching Large Milkweed Bugs.

The milkweed bugs are, like Monarch butterflies, dependent upon milkweeds. Monarch caterpillars eat leaves; milkweed bugs eat seeds. They are most visible now, as they congregate in large numbers on selected seed pods.

When we want a plant species to flourish, it can be tempting to resent the eating of seeds by wildlife. But, just as the practicec of Blue Jays consuming acorns does not prevent oaks from flourishing, so the loss of some milkweed seeds to insects does not constitute a threat to milkweeds or to Monarch butterflies.

Common Milkweed has long since finished flowering for this year and is now dropping its leaves. The seed pods remian.

This is a great time to stop by and take another look — before the seeds have all been blown away.

The Chestnuts Are Falling — and Disappearing

NOTE: This is the 200th post since I began this blog 34 months ago. I continue my nature walks in the park as there is much more to find, to observe, to experience, to research, to photograph, to wonder about, and to admire.

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The chestnut trees in Eliza Howell Park are quite fruitful again this year and the fruit is now ripening.

The nuts are inside burs covered with very sharp spines that quite effectively keep the fruit from being taken prematurely. While the ripe burs sometimes open while still on the tree, most seem to fall first, opening on the ground to reveal 2 or 3 nuts.

It is rare to find the nuts on the ground, however, since they quickly disappear, grabbed up almost immediately, with only empty burs left behind.

I suspect that squirrels take most of this desired food, either consuming the nuts on the spot or carrying them off for later. There are a variety of other animals that also find chestnuts both edible and desirable, including deer (according to reports) and humans.

The Eliza Howell chestnuts (I am not entirely sure of the exact species, perhaps Chinese Chestnut, perhaps a hybrid), are about an inch in diameter.

I have seen humans harvesting chestnuts in the park more often than I have seen them collecting hickory nuts or walnuts. Since humans are rarely able to beat other critters to the fallen nuts, they tend to harvest by picking the low-hanging fruit from the tree, dealing with the prickly spines as well as they can.

There is an unrelated tree/nut that might be confused with chestnut — the Buckeye or Horse Chestnut. Buckeye nuts, which are NOT edible, are considerabky larger and do not have the pointy end. The differences are evident in this picture (chestnut on the left; buckeye on the right).

My harvesting is limited so far this year to collecting a few for “study purposes.” I have found that the bur can be opened without pain to me or damage to the nuts by fairly gently rolling a bur under one’s boot.

Visitors to Eliza Howell often ask whether something is edible. The evidence is clear that chestnuts are prized as food by both wildlife and humans.

I am hoping that, one of these days, I will be able to confirm that the park deer are getting their fair share, as they get ready for rutting season

Oak Hedgehog Gall: Food and Shelter for Wasp Larvae

More than in past years, I have recently been paying attention to the insect galls that are found on oak leaves in Eliza Howell Park.

There are many kinds, but I have been focusing particularly on one called Hedgehog Gall, found on the midrib (middle leaf vein) of oak leaves.

Oak species are divided into two major groups: red oaks and white oaks. The tiny wasp responsible for the hedgehog gall, known as the “hedgehog gall wasp,” has a distinct preference for white oaks. The gall is much better known than the wasp.

This is on a Chinkapin Oak, one type of white oak.

As leaves are developing in the spring, the wasp lays eggs and stimulates the tree to abnormal growth at the egg site. The gall is a growth produced by the plant, not the wasp, but it provides the seasonal home and the nutrients for the wasp larvae to feed and grow. Each hedgehog gall has a few cells for developing larvae.

Though the galls are often round, they get their name from the shape that is thought to resemble a hedgehog.

These galls can be found on either the top or underside of white oak leaves and have orangish or reddish hairs. They might look soft, but are very firm, providing excellent protection for the wasp larvae.

If I have my identification correct, these are all hedgehog galls.

Since I started looking carefully, I have been finding many other types of galls on oak leaves. The ones represented in this collage are mostly on red oak trees.

An oak leaf gall is an amazing phenomenon. The insect induces the tree to build a “nest” to raise its young. And, as galls rarely do the tree any real harm, the cost to the tree is minimal. Another of Mother Nature’s many ways of living together.

Virginia Creeper: Fall Color Season Begins

“Leaves of three, let it be. Leaves of five, let it thrive.” The first line of this rhyme, referring to Poison Ivy, is better known than the second. The second vine is Virginia Creeper, similar to Poison ivy in some ways, but with five leaflets instead of three — and much more welcome.

Late in September, Virginia Creeper is one of the most stunning plants in Eliza Howell Park.

Virginia Creeper is both a creeper and climber. It clings to trunks and drapes itself over dead and living branches, turning red or burgandy in contrast to the often green or yellow of surrounding plants.

Though an aggressive grower capable of climbing large trees, Virginia Creeper is not considered a threat to the health and vitality of the natural environment. It is native to our area, a vine with which other native plants have long been compatible. (This map of its native range is taken from Ontario Wildflowers.)

Attractive as the leaves are in early Fall, for some viewers the appearance of the fruit is even more striking, dark blue berries on red stems.

While the berries are usually described as toxic to hunans, they do not last long after they ripen, eagerly eaten by both mammals and birds. Some 30 species of songbirds have been confirmed as comsuming them, Norther Flicker being one.

(Photo courtesy of Margaret Weber.)

Fall leaf season is now starting in Eliza Howell. Virginia Creeper is contibuting to an excellent beginning.

New England Aster: The End of Summer

Since April 23, I have written about different wildflowers of Eliza Howell Park 10 times. The flowers have been irresistible this year and I have been excited to learn that the park has even more species than I had thought.

As summer ends, the flowers are fading fast. One more species should be featured, however, before the flower season is totally over: New England Aster.

I have long thought that the signature flower of September in Eliza Howell is Goldenrod. And it is dominant this month. But the bright purple aster is an additional highlight and the two go together extremely well.

New England Aster is a late season bloomer, found in open fields and at the edges of forest. It is native to much of North America.

Most of the asters in Eliza Howell grow to about 4 feet high, scattered in the wildflower prairie in the park, not forming large patches. They repeatedly invite me to get closer to admire both individual blooms and clusters.

I feature New England Aster as my last flower post of 2020 not because it is rare or unusual, but because it announces the end of sunmer. September is truly a month of transition for flowering plants in Southeast Michigan: at the beginning of the month many of the summer flowers continue to thrive; at the end of September there are very few that have not faded.

New England Aster is perhaps the brightest of the fall wildflowers.

Four months ago the alpha of this year’s featured flowers was the delicate Spring Beauty. I think New England Aster is a deserving onega.

Bald-faced Hornets: Locating the Nests

One of the greatest benefits of taking many nature walks in the same location year after year is a growing ability to identify patterns, to learn the WHEN and the WHERE of nature’s annual cycle.

Near the beginning of September, I expect to see the first of the 8 or more Bald-faced Hornet nests that I find every year in Eliza Howell Park

This year it was September 3.

Bald-faced Hornets are a type of social wasp (“social” here means living in a colony that has a queen and workers). They are fairly large and are an attractive black and white.

The construction of the nest was begun much earlier in the season by the queeen, the only one to survive the winter, but I do not see the nests until they are full size. The large nest (roughly basketball size, but shaped more like a football) hangs among tree leaves, usually well enough hidden (until the leves fall) that it is difficult to find despite the size.

In September, the entrance way, located near the bottom, is busy with traffic, as can be seen in this photo taken by Kevin Murphy.

Based on observations from previous years, I have had a good idea about WHEN to find the nests. But identifying the WHERE has been more difficult. They are constructed in a variety of deciduous trees in different locations in the park.

The last couple of years, though, I did notice one or two each year in the maple trees along the the entrance drive from Fenkell.

So this year, when it was time, I made a point of checking these trees very carefully.

During the first week in September, I found, in addition to the one pictured at the beginning of this post, the 4 others that are in this collage. All 5 are in these maple, from about 8 to 15 feet from the ground.

I will no doubt find this year’s other nests scattered around over many acres, but I have now identified some sort of a pattern regarding location. Next year my search will likely start here again and will include other similar maple trees

Butterflies on Purple Coneflowers: A Photo Report

This has been a great summer for butterflies in Detroit’s Eliza Howell Park.

Since nectaring butterflies frequent Purple Coneflowers, for about three weeks starting on July 20 this summer, my butterfly watching regularly included a stop at a coneflower clump or two. With the flowers at the top of the plants, some three feet high, the coneflowers provide an excellent opportunity for picture taking.

American Lady (July 20)

Monarch (July 23)

Giant Swallowtail  (July 24)

Painted Lady (July 27)

Eastern Tiger Swallowtail (July 28)

Viceroy (July 31)

Black Swallowtail (July 31)

Red Admiral (August 5)

Clouded Sulphur (August 7)

Pearl Crescent  (August 8)

The coneflowers have now gone to seed. But they will bloom again next July and  the butterflies will be back. I am also planning to be there.

Bur Oak: Singing Its Praises

Among the many different species of oak trees found in Eliza Howell Park, Bur Oak is one that, in my mind, merits special recognition.

My attention starts with the acorns. Ever since I was young, I have been fascinated by these large nuts, reportedly the largest of any North American oak, almostly entirely covered by a mossy cap.

I cannot resist taking pictures, even when the acorns are not yet mature.

In bumper crop years — and this year appears to be one — these acorns are so noticeable that the tree looks a lot like a fruit tree.

The leaves are also easily recognizable, large and wider near the end. This, too, I learned early and is one of the reasons I have always been able to identify this species in the midst of many other oaks.

Bur Oak lives life leisurely, growing slowly and living a long, long time. And as it survives decade after decade after decade, it can get to be massive.

I have more than once measured one particular Eliza Howell specimen.

At four and a half feet from the ground  the trunk has a circumference of well over 15 feet, which translates to a diameter of nearly 5 feet, perhaps the biggest tree in the park.

Using the standard method of estimating tree age based on diameter (and taking species growth rate into account), this individual is estimated to be nearly 300 years old.

In 1720, Detroit’s population was about 200 people.

Given how long these oaks have been growing, one can expect that Bur Oak is  native to this part of the country.

As this map suggests, Bur Oak is more of a prairie tree than it is a forest tree. It has been one of the key oak species in “oak openings” or “oak savannas.” 

Grasslands have historically burned with some regularity. Bur Oak’s bark is fit for this environment, thick enough to make it fire resistent.

There is a great variety of oaks — and acorns — in Eliza Howell and I am slowly getting to know many of them.

But I confess a stronger attraction to one of them than to (most of) the others. I am a Bur Oak fan.