foliage – Discover-Nature

Forest Floor

Two main types of forests grow in the regions between the tropics and the poles, deciduous forest and coniferous forest. A majority of energy from sunlight is captured by the canopy vegetation, with little leftover to reach the forest floor. And yet, the lowest level of the forest has an abundance of food and organisms.

Deciduous species are mainly hardwoods including oak, birch, maple, ash, beech, and hickory. These trees have leaves that are broad and flat, designed to catch sunlight. Conifer forests are made up mostly of softwood tree species from the pine and fir families. Most conifers have leaves that are long, thin, and needle-like, a compact form of leaf that is often waxy and designed to withstand the rigors of an environment that is cold and dry for long periods.

^{Green ash tree leaf in summer & autumn by Alain de Maximy}

Chlorophyll is a chemical that is synthesized by plants and gives leaves and needles their characteristic green color. Plants use chlorophyll to absorb energy from sunlight and use that energy to power the process of photosynthesis which creates carbohydrates, providing food for the rest of the plant. Senescence, the process that occurs when a plant stops making chlorophyll, happens as seasons change and day length shortens while temperatures fall. As chlorophyll is removed, leaves and needles lose their green hues and show their underlying colors of browns, reds, and oranges even as they die and fall to the forest floor.

^{Black beetle on forest floor by Undefined, Getty Images; Forest floor fungi cluster in Autumn woods by Vladimir Srajber, Pexels; Springtail on fallen log by Henrik L, Getty Images; Lush moss covering the forest floor by Doina Gherban}

Fallen leaves create a thick layer of litter, broken down by a rich variety of decomposers including mosses, fungi, insects, and other invertebrates. Decaying vegetation releases nutrients back into the soil to be used once more as food for other forest plants. The annual leaf fall adds an estimated 2,600 pounds of vegetation per acre back into forest habitats worldwide.

In deciduous forests, all of the leaves typically fall in late autumn opening up the forest floor to sunlight in early spring. A group of plants known as spring ephemerals take advantage of this sunlight to quickly flower, bloom, and reproduce before leaves re-appear and shade once more rules the forest floor. In conifer forests, where shade is ever-present, flora is restricted to shade-loving species such as ferns and fungi. In addition, fir and pine tree needles are high in acid content and their leaf litter is only broken down by a relatively few fungi species over long periods of time.

All forest floors are rich with many organisms present throughout the year. Invertebrates including insects, fungi, and small mammals spend their entire lives living in the leaf litter. Detritus from leaf fall provides food and nutrients throughout the year to the plants and other organisms living in these wonderful habitats. As you walk the forests, no matter what the season, think about all of the life going on around you each day on the rich woodland floor.

Greene Valley Trail

As the heat abated a little bit, we decided to take a hike at the DuPage County Greene Valley Forest Preserve in Naperville, Illinois, this past weekend. On the east side, in the central part of the preserve, a 2.25 mile trail loops from the south parking lot to the Southern DuPage County Regional Trail and the Valley Trail. Trails are well-marked, wide limestone paths, with plenty of room for walkers and bicycles.

We found a pleasant, open vista that was great for birdwatchers and prairie enthusiasts alike. The Valley Trail runs alongside the east branch of the DuPage River, which makes it attractive to bird species, although there is no view of the river for hikers. While it was an overcast day making bird identification difficult, we were able to observe those seen below:

^{Birds pictured above in clockwise order: Northern cardinal, Cardinalis cardinalis, by Mshake, Getty Images; Red-winged blackbird, Agelaius phoeniceus, by Robert Jakubowski, Pexels; Song sparrow, Melospiza melodia, by BrianEKushner, Getty Images; Common yellowthroat, Geothlypis trichas, by BrianEKushner, Getty Images; Field sparrow, Spizella pusilla, by Mr Jamsey, Getty Images Signature; Gray catbird, Dumetella carolinensis, by SKHoward, Getty Images Signature}

Vegetation varies greatly, providing good protection for many of the small mammals plus lots of perches for birds. Many plant varieties could be seen and identified without leaving the trails, including those pictured below.

Black raspberry, Rubus occidentalis; Edible in season
Climbing prairie rose, Rosa setigera; Pollinator species for bees
Common milkweed, Asclepias syriaca; Pollinator species supporting more than 450 species of insects
Cup plant, Silphium perfoliatum; Leaf wraps around the stem forming a water holding cup
Eastern Black Walnut, Juglans nigra; It is allelopathic, releasing chemicals from its roots that may give the tree some advantage over its nearest competitors for food and nutrients
Elderberry, Sambucus sp.; Sambucus is Greek for an ancient wind instrument sounding as a whistle
Grey headed coneflower, Ratibida pinnata; Perennial attractive to Butterflies & birds
Hemp dogbane, Apocynum cannabinum; All parts of the plant are toxic, possibly fatal
Joe Pye weed, Eutrochium sp; Considered medicinal by early American cultures
Northern red oak, Quercus rubra; Acorns need a minimum 3-month exposure to near freezing temperatures to germinate
Sumac, Rhus sp.; Prized as a spice from the cashew & mango tree families
Virginia creeper, Parthenocissus quinquefolia; Flowering vine in the grape family
Grey poplar, Populus x canescens; Cross between white poplar and Aspen
Wild bergamot, Monarda fistulosa; Considered medicinal in use as a tea for colds

^{Scroll through pictures above using the left & right arrows}

The area supported plenty of small mammals such as rabbit, shrew, deer, coyote, and both gray and fox squirrels. We saw lots of pollinators including bees, moths, butterflies, and dragonflies. Greene Valley Forest Preserve offers a wide range of hiking trails, a scenic overlook, camping and picnicking facilities, a model airplane field, and many events, including night sky observations throughout the year. Consider catching some of the amazing sights in natural areas near you.

^{Fauna pictured above in clockwise order: Coyote, Canis latrans, by Esteban Arango, pexels; Galls on grape leaves; White-tailed deer, Odocoileus virginianus, by Stefonlinton, Getty Images Signature; White cabbage butterfly, Pieris rapae, by Bejan Adrian, Pexels; Shrew by CreativeNature_nl, Getty Images; Eastern cottontail, Sylvilagus floridanus, by Brian Forsyth, Pexels}

Natives In Bloom

Spring has arrived in northern Illinois with warming temperatures and spring rains. At this time of year, we can observe many of the early ephemerals in bloom. Many of these species only bloom for a short period before the flowers are gone, but the plants continue to grow and put forth fruits and seeds before dying back altogether until next spring. Let’s take a look at what is blooming right now in our area.

^{Bloodroot, Sanguinaria canadensis, by DonArnold, 2025}

^{Bloodroot, Sanguinaria canadensis, colony by DonArnold, 2025}

Bloodroot, Sanguinaria canadensis, is one of the earliest plants to bloom as soon as warmer temperatures stabilize. It is a perennial that grows up to a foot tall. Each leaf unfolds to reveal a single white flower with bright yellow anthers. Each flower blooms for only one to two days, and the entire colony of plants last about two weeks.

^{Sharp-lobed hepatica, Hepatica nobilis acuta, by DonArnold, 2025}

Sharp-lobed hepatica, Hepatica nobilis acuta, a member of the buttercup family, reaches only a few inches in height. Flowers are white, pink, or blue, clustered in tufts of several blooms. They like woodlands and rocky bluffs, and flowers persist for two to three weeks.

^{Celandine poppy, Stylophorum diphyllum, by DonArnold, 2025}

Celandine poppy, Stylophorum diphyllum, is a taller plant between 12″ and 18″ in height. Each stem bursts forth in two to four golden yellow flowers. If cut open, the sap is an orangish-yellow color. After about three weeks, flowers die back and an inch long, ovoid seed capsule grows for several weeks before releasing numerous seeds upon splitting open.

^{Virginia bluebells, Mertensia virginica, by DonArnold, 2021}

Virginia bluebells, Mertensia virginica, stands tall at one to two feet. Pale pink or blue flower buds open to light blue tubular flowers. Blooms last about three weeks and make a dazzling display when plants are observed clustered over a large space in many shaded woodlands throughout the area.

^{Shooting Star, Dodecatheon meadia, by DonArnold, 2025}

Shooting star, Dodecatheon meadia, is a group of 17 subspecies of flowering plants found throughout North America and Siberia. Standing up to 18″ tall, a cluster of eight to twenty purple, pink, or white flowers with yellow stamens hang from the top of each stalk.

^{Spring Beauty, Claytonia virginica, by DonArnold, 2021}

Spring beauty flowers, Claytonia virginica, open on warm, sunny days but remain closed when clouds or cool breezes are present. They bloom for one to two months in late spring and like dappled sunlit areas. White blooms with pink lining give off a pleasant floral scent.

^{White trout lily, Erythronium albidum by DonArnold, 2021}

^{White Trout Lily bloom, Erythronium albidum, by DonArnold, 2021}

White trout lily, Erythronium albidum, grows in large patches of four to six inch high plants with bright white blooms that stand out among dark green leaves mottled with brown markings. The flower nods from a short stalk and blooms for about two weeks in late spring.

^{Cutleaf toothwort, Cardamine concatenata, by DonArnold, 2021}

Cutleaf toothwort, Cardamine concatenata, stands about ten inches tall with large-lobed, toothed leaves. Many small white flowers with yellow anthers bloom above the leaves for about two weeks.

^{Mayapple, Podophyllum peltatum, by DonArnold, 2021}

Mayapple, Podophyllum peltatum, stands up to eighteen inches tall. Infertile plants produce one leaf on a single stalk. Fertile plants have two leaves on petioles branching from the stalk, with a nodding flower growing from the juncture of the petioles. Flowers are pale white with a yellow or greenish middle.

^{Prairie trillium, Trillium recurvatum recurvatum, by Karly Tuminello}

^{Large-flowered trillium, Trillium grandiflorum, by СССР, May 2019}

Trillium grows in prairie and woodland habitats. There are seven recognized species, and two of the ones that you are most likely to observe in our area are large-flowered trillium, Trillium grandiflorum, and prairie trillium, Trillium recurvatum recurvatum. Large-flowered trillium is declining in population, preferring swamps or wet soil areas, which are also declining as development expands and destroys these habitats. Prairie trillium prefers open woodlands dominated by oak, hickory, and maple species. All species of trillium are notable for their structure consisting of three leaves and flowers with three petals.

^{Dutchmans Breeches, Dicentra cucullaria, by DonArnold, 2025}

^{Dutchmans Breeches, Dicentra cucullaria, by DonArnold, 2021}

Dutchman’s breeches, Dicentra cucullaria, stands about six inches tall, with a white flower shaped like a pair of pants hung upside-down from a pedicel. These plants are found in undisturbed woodlands, especially along ledges and ravines throughout Illinois.

^{Eastern redbud, Cercis canadensis, by Greg Hume, Apr 2005}

^{Eastern redbud, Cercis canadensis, buds up close by Greg Hume, Apr 2005}

Eastern redbud, Cercis canadensis, is a small tree or large shrub, growing up to thirty feet high. The bark is dark and smooth, and twigs are slender with a zig-zag appearance. Flowers bloom in mid to late spring and form small, vivid rose-colored bunches.

^{Serviceberry, Amalanchier sp, by DonArnold, 2025}

Amalanchier is a genus that includes about two dozen varieties of small trees or shrubs. These are known by several different common names including shadwood, serviceberry, sugarplum, saskatoon, and others. They bloom for short periods in late spring, displaying clusters of four to twenty white flowers. Small red berries grow in mid to late summer, but do not last long since they are a favorite food source for both birds and small mammals.

Getting out for a walk to your favorite prairie or woodland habitat over the next few weeks will provide the opportunity to observe many of these plants while they are in bloom, including our own woodland trail around Lake Benedictine here at the Jurica-Suchy Nature Museum.

Midwestern Prairie

Grasslands make up the largest habitat in North America and cover about one-quarter of the Earth’s surface. There are many different types of grasslands, each with its own descriptive name. Prairie, found in North America, is from the French word for “meadow;” steppes, found in Asia, is Russian for “flat, grassy plain;” pampas, found in South America, is from Quechua meaning “flat surface;” and veldt, found in Africa, is from Afrikaans meaning “field.” In all of these areas, grasslands are characterized by flat or gently rolling countryside.

From upper left: The African veldt by Cello8, May 2007; Sunrise on the Mongolian steppes by Nicolas Mirguet, Apr 2011; Pampas grasslands, Uruguay, South America by Guilherme Boettcher, May 2010; Nachusa Grasslands, Lee County, Illinois by Justin Meissen, Jul 2007

Prairies in Illinois were formed by the action of glaciers retreating northward at the end of the last ice age. Massive ice fields compacted the soils and flattened the landscape. Many areas retained much of the melting ice in ponds, creeks, and rivers. These provided much needed moisture to help establish the new flush of vegetation that moved in as the climate warmed.

White River Prairie, Wisconsin by Joshua Mayer, Aug 2016

Several different types of prairies can be found, differentiated by the mixture of grasses and flowering plants, called forbs. We classify prairies as wet, mesic, meaning moderately moist, or dry. The determination is made based on how much water is retained in soil layers, but can be greatly influenced by temperature, rainfall amounts, and fire. Grasses have narrow leaves, can grow in drier environments, and are the dominant plant type in most prairies. Forbs have broad leaves and require more moisture than grasses. Prairie plants often have deep root systems to access water and nutrients.

From upper left: Big Bluestem, Andropogon gerardii by Matt Lavin, Sep 2019; Rattlesnake master, Eryngium yuccifolium by Adam B, Jan 2017; Grey coneflower seed heads, Ratabida pinnata by JanetandPhil, Nov 2010; Frosty Prairie dock, Silphium terebinthinaceum by Anne McCormack, Dec 2010; Indian grass, Sorghastrum nutans by Douglas Mills, Sep 2015

Animals that inhabit midwestern prairies are adapted to this habitat. They are able to find water and food in drier conditions, when water is scarce. They avoid the hazards of fire sweeping across the landscape. They keep warm during cold winter months. They avoid predators in a landscape with few hiding spaces. Many species are able to burrow underground for warmth, to avoid fire, and to escape predators. Others live near the ground in thicker vegetation that provides cover from wind, cold, and attack.

From upper left: American toad, Bufo americanus by Alan Huett, Jul 2008; Sedge wren, Cistothorus platensis by Joshua Mayer, Jul 2015; Thirteen-lined ground squirrel, Spermophilus tridecemlineatus by ChristaR., Nov 2016; Prairie kingsnake, Lampropeltis calligaster by Peter Paplanus, May 2022; Northern harrier, Circus hudsonius by Wendy Miller, Dec 2010

At this time of year, prairie plants are starting to go dormant and many bird species are migrating southward to warmer climates where food and water is abundant. It is a great time to get out and observe plants as they set seed and surprise us with the many hues of autumn. Birds are abundant as flocks fly overhead on their migration. Birds that spend the winter here are searching for areas that will provide seed and cover during the coming cooler months. Other animals are out to gather plants for insulation in their winter dens or seeds to store in their larder. Keep your eyes and ears open as you walk the prairie paths this month.

Midewin tallgrass prairie preserve, Wilmington, IL by CheapShot, Jun 2012

Ash Trees

In the past, ash trees were one of the more common street trees in many urban areas of the United States. However, with the introduction of the Emerald ash borer, Agrilus planipennis, a member of the beetle family native to Asia, our native ash populations have suffered severe losses.

^{Emerald ash borer, Agrilus planipennis, by Leah Bauer, USDA FS Northern Research Station, Bugwood.org}

^{Emerald ash borer larva by Oregon Department of Agriculture, Mar 2023}

^{Emerald ash borer damage by John Hritz, Aug 2006}

Ash trees have been a popular “street tree” species for many urban areas. It is estimated that by the late 20th century, 20% of all parkway trees in Chicago were ash species. Green ash, Fraxinus pennsylvanica, likes moist soils, but grows well in most conditions. White ash, Fraxinus americana, is very similar to green ash, but prefers well-drained sites. Both have furrowed bark appearing as tight rectangular blocks on young trees, but deepening into longer furrows and ridges resembling a diamond-shaped pattern in mature trees. Black ash, Fraxinus nigra, often found on wet sites, is covered with irregular, knobby bumps. All the barks are grayish-brown.

^{Green ash, Fraxinus pennsylvanica, flowers by DonArnold, Aug 2023}

^{Ash tree samara by Herve Breton, Getty Images}

In spring, ash trees grow small green or purple flowers with no petals. Most are wind pollinated, although several bee species collect the pollen and contribute to some seed development. Flowers appear on both male and female trees, but only female trees develop seeds. Seeds are called samaras, or “helicopter seeds,” due to the distinctive whirling pattern they exhibit as they fall off the tree in a lazy spiral to the ground. The seed is housed in a fully rounded shell at one end of the single wing of each samara.

^{Green ash, pinnately compound leaves by Robert H. Mohlenbrock. 1989, USDA NRCS Wetland Science Institute (WSI), Lincoln}

Its pinnately compound leaves are another distinctive feature of the ash family. A compound leaf has a leaf blade divided into leaflets that are attached individually to the middle vein, each by its own stalk. The term pinnately refers to the arrangement of leaves, opposite one another along the middle vein. A terminal leaf, grown at the tip of the vein means there are always an odd number of leaflets, from 5 to 9 leaflets in ash species. Buds and branches also grow in this pattern, which can be observed on rose plants, as well as hickory and walnut trees.

^{White ash trees in autumn color by Cathy McCray, Nov 2016}

White ash is the main source of wood used in commercial applications. It is of medium weight and springy, able to absorb a shock and bounce back. This makes it valuable for bats, tennis rackets, bows and arrow shafts, along with a wide variety of other uses including tool handles, boats, and furniture. The seeds provide a valuable food source for several bird species including quail, duck, and turkey.

^{Green ash, Fraxinus pennsylvanica, bark by Kerry Woods, Apr 2022}

^{White ash, Fraxinus americana, bark by Virens, Sep 2009}

^{Black ash, Fraxinus nigra , bark by Robert H. Mohlenbrock, 1995, USDA NRCS Wetland Science Institute (WSI), Chester}

Although many, many ash trees have been lost to attacks from Emerald ash borers over the past couple decades, a small number of green ash have proven more resistant. They provide great shade for parks, yards, and large areas. In fall, watch as white ash trees turn beautiful shades of gold, deep purple, and maroon. Be sure to make note of them on your walks and check back in a few months to view their spectacular fall displays.

Oak-Hickory Forest

Oak-hickory forests makeup one-fourth of all the woodlands in the eastern United States. At the end of the last ice age, oaks were only found in the Appalachian Mountains and the driftless section where glaciers did not form in southwestern Wisconsin. In the last 15,000 years they have repopulated the land from the Mississippi River to the Atlantic coastline.

Clockwise from top left: Quercus alba, white oak by Chris Andrei, Getty Images; Quercus palustris, northern pin oak by Michel VIARD, Getty Images; Quercus rubra, northern red oak by ValerijaP, Getty Images; Fraxinus pennsylvanica, green ash by Garsya, Getty Images; Carya ovata, shagbark hickory by Elmar Langle, Getty Images; Prunus serotina, black cherry tree by Ina Hensel, Getty Images

Oak-hickory forests are an open woodland community where trees make up less than 10% of the plant life. Species of both the red oak and the white oak groups dominate these wood including Northern red oak, Quercus rubra, black oak, Quercus velutina, white oak, Quercus alba, and bur oak, Quercus macrocarpa. Two members of the hickory family, shagbark hickory, Carya ovata, and bitternut hickory, Carya cordiformis, are also found in abundance. These forests are rich with several other tree species most notably red maple, Acer rubrum, sugar maple, Acer saccharum, black cherry, Prunus serotina, black walnut, Juglans nigra, and green ash, Fraxinus pennsylvanica.

^{Arisaema triphyllum berries by ES3N, Getty Images}

^{Arisaema triphyllum, jack-in-the-pulpit by Holcy, Getty Images}

The open structure of the forest supports a large variety of other plants that offer food, shelter from predators and weather, and places to raise a family. Food sources are plentiful including fruit-bearing plants of the genus Vaccinium, which includes blueberries and raspberries, and vines from the genus Vitis, which includes several species of wild grape. Bloodroot, Sanguinaria canadensis, and Jack-in-the-pulpit, Arisaema triphyllum, along with several clovers, attract birds and insects that attract larger predators, creating a rich forest community. It is estimated that oak-hickory forests support over 300 animal species including birds, mammals, insects, reptiles and amphibians.

^{Oak woodland by fotoVoyager, Getty Images Signature}

Oak trees provide a haven for wildlife. Acorns, the fruit of an oak tree, are large and heavy, so they do not spread far from the tree. They offer good nutrition and are a favorite of many wildlife species, whether eaten immediately or cached and eaten over time. Oak trees retain their dead leaves throughout the winter, not letting them fall until early spring. The leaves provide shelter from wind and rain, as well as hiding many smaller birds and mammals from airborne predators. Oak trees have craggy bark providing shelter for insects and other small animals including many amphibian species that overwinter under the bark.

After dying, oak leaves retain tannin, a chemical that slows down their decay. As leaves build up on the forest floor year after year, they create thick layers used by amphibians, reptiles, small mammals, and insects for shelter from predators and weather. In winter, the leaf layer provides insulation from the snow and cold, allowing small animals to move around under the snow, hunting for food, or moving to other sites. However, the leaves can be advantageous to some predators, as well. Owls, and other nighttime hunters, have excellent hearing and can easily detect the sounds from crackling leaves as prey attempts to hide and flee.

^{Gnarled tree with large cavity from wepix, Getty Images Signature}

^{Nature lives forever in fallen trunks by Oleksiy Brunets, Getty Images}

Many tree species are susceptible to dry rot of their interior wood, and none more-so than members of the red oak family. This provides natural cavities for woodland species. Woodpeckers, owls, chickadees, and nuthatches, plus squirrels, raccoons, bats, amphibians, and reptiles all use cavities for shelter and protection. Almost 40% of animal species inhabiting oak-hickory forests will use cavities at some point in their lifetimes. As trunks and branches decay and fall to the forest floor, they create opportunities for food and shelter. In addition, animals drawn to these spaces provide food for larger predators.

As you walk through forested areas over the summer, take note of the tree species and the overall structure you observe Can you spot holes in trees, logs laying on the forest floor, and thicker layers of leaf cover? Are the woods open where you can see possible lanes of movement? What plants have fruit or seeds? Keeping a journal of observations helps us to identify the changes and enjoy these rich habitats.

^{Dry oak forest in springtime by Meinzahn, Getty Images}

^{Swamp oak forest in springtime by Aleksander, Getty Images}

Ferns

Ferns are a group of well-known plants that first developed during the carboniferous period about 350 million years ago when the climate was stable, warm, and wet. Ferns were globally abundant in woodlands and marshlands providing suitable habitat for them.

Ferns were the first group of plants with vascular systems. Vascular plants utilize tube-like structures, called xylem tissue and phloem tissue. Water and minerals are moved from roots to fronds (leaves) through the xylem tissues and are used in photosynthesis to create food that is distributed throughout the rest of the plant in phloem tissues. Vascular systems also provide internal support so these plants can stand upright on their own.

^{Fertile fronds, Christmas fern in Sheipsit State Forest, CT by Holcy, Getty Images}

Early scientists noted that ferns came back every year, but produced no flowers or seeds. In 1669, it was discovered that spores grew on the surface of the fronds, but it was not until the mid-18th century that the entire reproductive process was understood. Spores are one-celled organisms that start to develop in springtime. They appear by the thousands as small green bumps on the undersides of fronds. As summer progresses, the sporangia, a capsule that contains the spore, turns brown. Clumps of these are called sori, and can easily be observed on fern fronds. In late summer, when the sporangia mature, they open and release their spores. Some plants will forcefully shoot their spores away from the fronds and some will open and let the spores drift away, caught by any small breeze.

^{Polystichum richardii in Stanley Park, Akaroa by Jon Sullivan, Aug 2006}

^{Lady fern sporangia by Kerry Woods, Mar 2013}

Most spores will not land in a spot with favorable growing conditions (fertile soil and water), but the spore may remain viable for up to a year, should conditions change. Spores do not contain a small plant like a seed does. A spore starts as a one-celled organism that grows by dividing itself in two during the first phase of reproduction called the gametophyte generation. As this division continues, a small structure called a prothallium grows, getting its nutrients directly from contact with water. Two more structures develop. The archegonium contains an egg, and the antheridium contains sperm. When water is present, the sperm will swim to the egg, fertilize it, and eventually a new, self-supporting plant grows.

^{Crozier shaped fronds by Ray Hems, Getty Images Signature}

The fern develops underground over the winter. In spring, when ground temperatures have risen, fernlets will push tightly coiled fiddleheads through the soil into the open air. A fiddlehead, also called a crozier, is a group of young, coiled fronds (leaves) of a fern. As the fern grows, the upper and lower surfaces of the fronds grow at different rates, and the fiddlehead uncoils, straightening out into several fronds. The plant is entering the second phase of reproduction, known as the sporophyte generation, where spores will be grown on the undersides of the fronds.

^{Green Boston fern frond, Nephrolepsis exaltata by Noppharat05081977 Getty Images}

^{Staghorn fern frond veins by IveehCoombs_Photography, Getty Images}

^{Staghorn ferns by Eyepark, Getty Images}

Ferns can also reproduce through cloning. The walking fern, Asplenium rhizophyllum, grows long fronds that eventually bend over and touch the ground. Wherever a tip touches moist soil, new roots are sent out, and a cloned plant develops. The Boston fern, Nephrolepsis exaltata, grows runners – leafless stems that branch out horizontally. Wherever they come in contact with moist soil, roots are sent out to clone another Boston fern. The staghorn fern, Platycerium sp, grows buds on its roots. As the soil around the plant is moistened by water containing nutrients, a new plant pushes upward through the soil from each bud.

^{Walking fern, Low Tatras mountains, Slovakia by Vrabelpeter1, Getty Images}

Ferns grow well in a variety of habitats. Many species prefer damp woodlands, but some grow on cliff faces or in rocky, dry locations. Be sure to watch for various species of ferns when you are out walking. A good field guide can help with fern identification and provide distinguishing information on this amazing plant group.

Maple Trees

Maple trees in the northern U.S. are coming into bloom at this time of year. Maples bloom in late winter and early spring, and the flowers come in green, yellow, orange, and red hues. There are about 130 species worldwide, and except for one species, all are found in the northern hemisphere across Asia, Europe, Africa, and North America. Thirteen maple trees are native to North America, and we will take a look at a few of the more common ones.

^{Holland Red Maple Swamp, Wisconsin State Natural Area by Joshua Mayer, May 2012}

Several species are large trees, reaching from 40′ to 65′ in height with 20″ to 60″ diameter trunks. Trunks are dark grayish-brown with ridged bark. Crowns appear generally rounded and root systems are widely spread. Maple trees do well in most habitats, particularly moist to wet soil, along streams or in bottomlands.

^{Sugar maple in spring by J Stephen Conn, Jul 2007}

Sugar maple, Acer saccharum, is well known for its maple syrup, marketed world-wide. When temperatures drop below 40˚, maple trees stop growing and excess starch is stored until temperatures start to rise again. Enzymes in the tree change the starch into sugar which is carried by tree sap flowing through the xylem and phloem cells, located just beneath the bark. A tap gently pounded through the bark intercepts some of the sap and collects it into buckets. It takes 40 gallons of sap to produce one gallon of maple syrup. Historically, the wood was used for railroad rails, plow blades, and wagon wheels. After burning, its ashes are rich in potash and make excellent fertilizer as well as an additive for soap and pottery glazing.

^{Maple tree tapping by PublicDomainPictures , Pixabay}

Black maple, Acer nigrum, is a close relative to the sugar maple, and these two species easily hybridize. Both species are shade tolerant, often found growing together for several years as understory trees. Sap from black maple trees may also be used in maple syrup production. Black and sugar maples are hardwoods, stronger and harder than other maple species, and valued for use as basketball court and bowling alley floors, workbenches, cutting boards, and baseball bats.

^{Bowling alley by vtwinpixel, Getty Images; Maple & other baseball bats by Comstock Images: Maple workbenches from thelinke, Getty Images Signature}

Red maple, Acer rubrum, provides food from seeds, buds, and flowers for squirrels, chipmunks, deer, moose, and elk. In winter, stumps and small twigs are an important food source for rabbits. Pollen is produced early in the spring and is a much needed food source at this time of year for bees and other pollinators. Red maple is also attractive to insects and fungi, which invade the wood and create many open cavities in trunks and large branches, favored as nesting sites for wood ducks and other species.

^{Red maple buds & flowers by Martin LaBar, March 2010}

^{Baby squirrel in maple tree by William Krumpelman, Getty Images}

Red maple has several qualities that have made it a widely used ornamental tree. It grows well in shady sites; it is tolerant of flooding and water-logged soils; it is one of the first to colonize disturbed sites and anchor the soil, and it has a rapid growth rate, colorful flowers and foliage, and lives 75 to 100 years. Maple flavored drinks, such as tea, are made from inner bark scrapings. Bark is also used in the production of ink and black or brown dyes. The wood is used for smoking meat and in the production of some whisky varieties.

Silver maple, Acer saccharinum, is a fast growing tree with a root system attracted to any source of water. It is easily grown in shady areas and wet soils, make it a well-liked ornamental tree. However, it causes many sewer and drain issues in urban settings in its search for water. The wood is hard but very brittle, and branches easily break in heavy winds. This often results in trunks having hollow cavities used for shelter by various animal species including wood ducks and squirrels. Seeds are abundant and are a favorite for birds and small mammals. The sap makes a delicious syrup, but requires twice as much volume as sugar maple trees, making it not commercially viable.

Box elder, Acer negundo, is another maple species that is often found near water. This tree easily tolerates drought and extreme cold, although the wood is weak compared to other maple species, and branches often break when subjected to heavy loads of snow and ice. Box elder produces abundant seeds late in the year that provide a great winter food source for mice, squirrels, and seed-eating birds. Branches are small in diameter, so it is not often used for lumber, but it has several uses as pulp wood for producing crates, boxes, and composite wood panels.

^{Under the spreading maple by Jo Zimny, Oct 2020}

As you are out walking in your area, be sure to look for the many species of maple trees that grow in yards and woodlands, often distinguished by bright flowers, abundant seeds, and lively green foliage. Also, be sure to take the chance to observe their spectacular fall foliage later in the year.