Everywhere I look this fall is golden yellow with goldenrod.
All through fields alongside the interstate, in the Butler Prairie and in my home garden. The most common goldenrod in our area is tall or Canada goldenrod, Solidago canadensis. This native plant loves old fields and the edges of road and woods. It is a showy yellow-flowered plant that is falsely maligned as a hay fever trigger. Goldenrods are pollinated by insects. The plants make heavy pollen that sticks to insects like bees that carry the pollen from plant to plant to carry out cross fertilization and pollination. Plants like grasses and ragweed produce prolific amounts of pollen and rely on the wind to carry it from plant to plant.
Great bugs on goldenrod
They make flowers without colorful petals because it is not necessary to attract pollinators. This method of vectoring pollen does result in the production of copious amounts that can end up in the noses of susceptible people, resulting in the allergic reaction referred to as hay fever. Ragweed and goldenrod bloom at the same time of year, so folks attributed the cause of hay fever to the colorful plants they saw blooming.
I was contacted several years ago by a researcher who wondered if changes in pollen quality might be responsible for honey bee colony collapse. He claimed goldenrod pollen is the primary food for many bees in the fall, and wondered if climate change may be affecting pollen protein levels. We hoped to be able to collect pollen from herbarium specimens to compare pollen from 40 years ago with that from goldenrods growing today in the same location. Unfortunately, the herbarium specimens did not contain enough pollen to test.
Blue-stemmed goldenrod from my garden. Smaller and tamer than Canada, bought at the INPAWS plant sale several years ago.
Canada goldenrod in my garden
Oakleaf hydrangea (Hydrangea quercifolia [Quercus is the oak genus]) is native to the southeastern US, but was not found in Indiana in presettlement times. It is well-suited to the Hoosier lifestyle, however. Its leaves are shaped like oak leaves, and its flowers look hydrangea-like, with elongated flower clusters.
Both cream-colored and pinkish petal varieties are available. There is a nice stand of the pink form at the IndyGo office downtown.
Oakleaf Hydrangea has a graceful branching pattern with interesting bark that peels off to reveal different hues of reddish and cinnamon-brownish layers. The leaves turn reddish in the fall, adding more seasonal color.
Like the common purple/pink hydrangeas, you can dry the flowers and enjoy this plant in arrangements through the winter.
Sally and Harmon Weeks great recent book on shrubs and vines of Indiana* lists only one Hydrangea native to Indiana, Hydrangea arborescens, wild hydrangea. I’ve seen it at Marrott Park Nature Preserve. It has smaller, less conspicuous flowers than those used in horticulture, but you can recognize the basic floral theme as Hydrangea.
*Purdue University Press ISBN: 978-1-55753-610-5. $45.00
Zigzag spiderwort in my neighbor’s sunny garden
Spiderworts (Tradescantia spp.) and Day-flowers (Commelina spp.) are the only members of the Commelinaceae, the Spiderwort family in the Indiana flora. They are all monocots, with parallel leaf veins and flowers made of three parts or multiples of three.
There are four species of Spiderwort in the state. The common name comes from the arrangement of the flowers on the ends of the inflorescences with bracts underneath that curve back like the legs of a spider. We have Glaucous spiderwort (Tradescantia ohioensis) in the Butler Prairie. Flowers are a brilliant florescent blue in early June, especially on cloudy days. I bought some at the INPAWS auction a few ago that reliably bloom in my sunny front garden.
Three petals and six stamens of Spiderwort
Virginia spiderwort (T. virginiana) and Zigzag spiderwort (T. subaspera) are found in woods. Virginia spiderwort blooms in late spring; Zigzag a little later in the summer. The fourth species in Indiana is a non-native found in the north.
Day-flowers with their wandering-Jew-like leaves.
Day-flowers get their name because they only last one day, opening in the morning and fading by day’s end. Ours in Marion County are Common Day flowers (Commelina communis), non-native but not fiercely invasive. I see them along the edges of the Butler Woods. The photos are from the front steps of the International School. The flowers are beautiful and delicate, with two pale blue petals and one white petal.
Delicate flowers of Day-flower
Last year’s leaves are a beautiful tan color
This time of year is one of the best for seeing small American beech (Fagus grandifolia) trees in forests in Central Indiana.
Beeches tend to keep their light tan colored leaves throughout the winter. You can detect small trees in the woods as you drive along I-65 in southern Indiana or along US 31 to the north. These small trees are a hopeful sign that beech is replacing itself. On the Butler University campus we have lost several very large and very old trees in the last few years, trees we estimate to be over 300 years old. Forty percent of Witness Trees identified in surveys conducted in Marion County in the 1820s were beech. My recent surveys of forest remnants found less than 2 percent remaining, while there has been a great increase in sugar maple. Sugar maple is thought to be on the increase in some areas due to fire suppression. Lack of fire, a natural disturbance in presettlement forests, allows more sugar maples to establish and survive. Sugar maple is easily killed by fire. I have always wondered if loss of passenger pigeons affected seed dispersal and regeneration of beech.
A few tan leaves remain on the small beech tree in the center of the photo
Nice smooth gray bark of an American Beech tree with tan leaves still retained on the tree
Open-grown white oak tree on the Butler University campus
This time of year is a good time for noting individual trees in the landscape. Their shape and growth form helps you know the history of a site. Trees that grow in forests tend to have few outward extending lateral branches. Open-grown trees, free from competition with other trees for light that occurs in forests, tend to have large lateral branches. Some natural habitats, like savannas, are characterized by scattered open-grown trees. In central Indiana, large open-grown trees are mostly found in yards and parks where they have been planted or in places where the woods around them was cleared a long time ago when they were small young trees.
Open-grown tree near Atherton Union that was part of the landscaping of Fairview Park
There are some classic open-growth architecture trees on the Butler University campus. The campus was Fairview Park prior to Butler moving to the Butler-Tarkington neighborhood in the late 1920s. A ring of oak trees partially surrounding Atherton Student Center are amazing examples of the open- grown form. They must have been planted around the time Fairview Park was established at the turn of the 20th century.
Evergreen trees in the landscaping at Butler University.
Another striking feature of the landscape this time of year is the presence of evergreens. All conifers, cone-bearing trees, in Marion County have been planted, with the possible exception of Eastern red cedar, Juniperus Virginia, based on early records of the native flora. All the winter color and wildlife cover they provide are the result of human efforts.
Traditionally the 3rd week in October is peek color time for fall foliage in our area. Despite the unusual weather extremes this summer it seems to be true this year, too. This is the best time of year to distinguish the different hardwood trees that make up our Central Indiana Forests.
A few weeks ago I could see the reddish-purple hue of green ash in the woods along roads and highways. This lets you know how many trees are likely to succumb to the Emerald Ash Borer. This week it seems the sugar maples are ablaze with red-orange. Hackberries turn pale yellow-green; oaks a burnished russet or copper.
For more information on leaves and why they turn color check out our Herbarium website at www.butler.edu/herbarium. We have a whole section on trees and the Butler tree walk.
Sugar maple branch
Two other fall items of note. This seems to be a super year for fruit on redbuds. I wrote about these small trees, members of the bean or legume family, in the spring.
Redbud fruits are legumes, dry at maturity, splitting along 2 sides to release seeds
Following their nice floral display, now you can see the legume fruits, like small, dry beans, that hang from the branches.
A favorite shrub for fall color is chokeberry.
As nice a red as the nasty, invasive, non-native, popular landscaping ornamental burning-bush, it also produces tasty fruit for birds to eat throughout the winter.
Chokeberry fruits. Bitter compounds break down and may even ferment through the winter, making the berries more tasty to birds