Spring Wildflowers of Central Michigan (Part II)

By April 25, 2020 No Comments

This is Part II of a three part series highlighting the spring wildflowers of Central Michigan.

In Part I we discussed why Central Michigan has such an abundance of wildflower species and highlighted some of the earliest bloomers including Skunk Cabbage, Bloodroot, and several species of Violets. In this installment, we continue with fifteen more of the species that make our Spring woodlands and wetlands a destination not to be missed.

Broad-leaved Toothwort (Cardamine diphylla) is the first of four closely species in the Mustard family (Brassicaceae). Like all members of this family, the flowers of this species have four petals. Each white flower measures about 1/2 inch across.  Several flowers are arranged in a loose cluster at the top of the plant’s main stem. The plants have a pair of compound leaves with three leaflets with coarsely toothed margins.  The leaves are arranged opposite or nearly opposite on the plant’s stem. This species often spreads from its roots and forms dense colonies of genetically identical plants.

This species likes rich moist soils and is found mainly in moist deciduous and coniferous woods.  Broad-leaved Toothwort flowers bloom in April to early June. In addition to Broad-leaved Toothwort, this species is also known as Two-leaved Toothwort or Crinkleroot.

While Cut-leaved Toothwort (Cardamine concatenata) has similar white flowers to those of C. diphylla, the two species can easily be differentiated by their leaves. Those of Cut-leaved Toothwort grow in a whorl of three leaves.  Each of these leaves is deeply “cut” into three to five lobes with toothed margins. 

Cut-leaved Toothwort can often be found in dense colonies – it reproduces both by seeds and rhizomes. Look for this species in places with rich moist soil such as deciduous woods, floodplains, and shorelines. These species blooms between March and May.

Spring Cress (Cardamine bulbosa) is the third member of this group of related species. Like the previous two, it’s flowers measure about 1/2 inch wide and 1 inch long. Spring Cress flowers vary in color from white to pink.

Spring Cress has both leaves at the base of the plant and on the stem. The basal leaves are rounded or kidney-shaped. The leaves on the stem are either oval or lanceolate (shaped like a spear or lance point); they may have smooth margins or be coarsely toothed.

Unlike the previous two species, Spring Cress is truly a wetland plant. Look for it floodplain forests, swamps, wet meadows between April and May.

Our final Cardamine on the list is Pennsylvania Bitter Cress (Cardamine pensylvanica). Like Spring Cress, this species loves wet soils. It is normally found in swamps, wet woodlands, wet meadows, and around springs and seeps.

Pennsylvania Bittercress is best identified by its leaves.  It has compound leaves, but the separate leaflets often grow together along the stem (especially the three leaflets closest to the end of the leaf).  Like the previous three species, Pennsylvania Bittercress has small white flowers with four petals, but the flowers of Pennsylvania Bitter Cress are tiny and measure only about 1/8 inch.

Wild Ginger (Asarum canadense) grows in moist deciduous woods, floodplains, and along the banks of streams. It spreads by rhizomes and forms large colonies that share a common root system. It is named after the Ginger plant (Zingiber officinale) which is native to Asia.  The Wild Ginger of North America has a similar smell and taste to the Asian ginger and has historically been used as a substitute for it in cooking and brewing – although this is not recommended because of the presence of a chemical called aristolochic acid that can cause kidney failure. 

Wild Ginger has broad heart- or kidney-shaped leaves covered with fine “hairs” that make the plant feel like velvet. The urn-shaped flower of the Wild Ginger grows from the fork between two leaf stems.  The 1-inch flower has three petal-like sepals that curl backward from the opening.  This flower varies in color from brown to purple and sometimes greenish-red.  Like the rest of the plant, the flower is covered with fine “hairs”. The flower often sits directly on the ground and attracts ground-dwelling beetles as its main pollinator. The plant blooms usually blooms in Central Michigan between late April and early June. 

Many of the spring wildflowers are small and unassuming; Large-flowered Trillium (Trillium grandiflorum) is anything but! The large size of the plant and the distinctive three-petaled flowers make the Large-flowered Trillium one of the Michigan’s most recognized and beloved wildflowers.  While this plant may bloom any time between April and June, in Central Michigan the bloom usually peaks around the 3rd or 4th week of April into the 1st week of May.

Sometimes you might find trilliums that have petals that are partly (or wholly) green.  This is the result of an infection by a mycoplasma.  A mycoplasma is a form of bacteria that lacks a cell wall.  This infection will first be noted as a green stripe near the center of each petal.  As the infection spreads in successive years the stripe widens until the whole petal may be green.  This infection can also cause deformed petals or even double blooms (so each flower would have six instead of three petals).  This infection eventually impairs the reproductive ability of the infected plant and prevents successful seed production. If you want to find a population of mycoplasma infected trillium check in Audubon Woods Preserve.

A second species of trillium can be easily found in Central Michigan. Unlike the proud upright flowers of the T. grandiflorum, those of the Nodding Trillium (Trillium cernuum) are hidden beneath its whorl of three leaves.

The cernuum in Trillium cernuum means “nodding or drooping” in Latin.  Although the plant can grow quite large (6 – 24 inches tall), this drooping habit makes these flowers much harder to spot in the woods than other species of trilliums.  To really see this flower you have to get down on the ground and look up at it.

Look for Nodding Trillium in cool wet woodlands, floodplains, and along the borders of swamps. In our area this species normally blooms during the first two weeks of May, but may flower as late as June.

Wild Geranium (Geranium maculatum) is a shade-loving plant found naturally in woodlands, along woodland edges, in savannas, and in partially shaded meadows. Wild Geranium blooms from May into June in Central Michigan and bridge the gap between the early spring ephemerals and summer blooming wildflowers. 

Virginia Waterleaf (Hydrophyllum virginianum) is a relatively low growing perennial wildflower of damp deciduous woodlands that blooms between May and August.  The white (or pink) flowers of Virginia Waterleaf are an important nectar source for bumblebees and other native bees.

The species is named a “waterleaf” because its leaves often bear a faint whitish mark that looks like a waterstain.

Anyone who tramps through the wet woodlands, floodplains, marshes and swamps of Central Michigan has probably come across the Marsh Marigold (Caltha palustris). In our region, Marsh Marigold usually blooms between mid-April and June. 

The Marsh Marigold has yellow flowers with five petals.  The flowers resemble those of a buttercup more than those of a marigold.  Marsh Marigold has glossy green heart- or kidney-shaped leaves.  In its preferred habitats, Marsh Marigold can form an extensive carpet. 

The flowers of Spring , with a few exceptions such as Large-flowered Trillium (Trillium grandiflorum) and Marsh Marigold (Caltha palustris), the wildflowers of Spring are generally more delicate and merit a closer inspection, especially the Two-leaf Mitrewort (Mitella diphylla).  Mitreleaf flowers are small (about 1/4 inch across), but quite spectacular when viewed closely.  Each flower has five fringed white to cream petals.  The fringed petals give the flower the appearance of a snowflake.

These flowers can be found between April and June, with most plants in Mid-Michigan blooming in May. Although the Two-leaf Mitrewort will grow in a variety of conditions ranging from wet to dry, it is typically found in locations with moist soil, such as Beech-Sugar Maple Forests and along the edges of swamps.

A note on the name: The fruit (and to a lesser extent the flowers) of Mitrewort bears a distinct resemblance to the triangular shape of the headgear of a bishop of the Catholic Church – the mitre. The Mitella in the scientific name translates to “little cap”. The species is alternately known as Bishop’s Cap.

Foamflower (Tiarella cordifolia) is often found in wet areas of deciduous and mixed forests. It is named Foamflower because the flowers long bear long stamen that give the flower a feathery or frothy appearance. Foamflower is also known as False Mitrewort because its leaves resemble those of Two-leaf Mitrewort.

Minor changes in topography, light, and moisture can play a major role in the presence or absence of all woodland and species. The above picture was taken on a hummock at the base of a tree in the middle of a cedar swamp. This miniature hill measured no more than ten feet by ten feet, but it provided home to several species that could not survive in the wetter soils only feet away. Nearby a decayed log provided a similar elevated platform and hosted its own small colony of Foamflower.

False Rue Anemone (Enemion biternatum) is another perennial, ephemeral, woodland wildflower.  It blooms between April and May and completes it yearly cycle of growth before the overhead canopy fills in.  After it completes it annual cycle, the above-ground parts of the plant will die back and the plant will remain dormant until the following Spring.  This plant often form large colonies and is found in a variety of forested habitats.

The next two plants are true Anemones. Canada Anemone (Anemone canadensis) is a flower that bridges the gap between spring and summer. Look for this flower to begin blooming in Late May and continue into August. This species is adaptable to a variety of sunny and partially sunny habitats such as prairies, wet meadows, and open woodlands.

Canada Anemone spreads easily both by seeds and rhizomes.  Given favorable conditions, it readily forms large colonies that can out-compete other native plants.  This tendency causes many wildflower gardeners, who might otherwise favor the plant, to be against its use.  Some gardeners will go as far to call the plant invasive.  (Even if a native plant crowds out other species, it cannot be called invasive – the proper term for this habit in a native plant is aggressive.  Invasive refers only to those aggressive plants that are outside their natural range.  Most alien species are not aggressive and cannot be classified as invasive.)

Growing to a height of no more than 8 inches, Wood Anemone (Anemone quinquefolia) has a much more delicate appearance than A. canadensis. The plant has a whorl of three leaves that are each deeply divided into 3 to 5 lobes. A single white flower (measuring up to 1 inch) rises up above the leaves.

Wood Anemone is adaptable to a wide range of soil conditions and can be found in shaded habitats including deciduous forests, coniferous forests, floodplains, and swamps. Like Canada Anemone, Wood Anemone spreads easily and often forms large colonies. Look for this species between April and June.

The third and final part of this series will focus on an additional fifteen species. Until then, we hope you are inspired to go explore our fabulous natural world!