A Visit to a Fen

Fens are fascinating. They are sedge peat areas with little, if any, standing water. Groundwater flows through a peat layer that is close to the surface. Less acid than a sphagnum bog, fens host a different community of plants and animals. Unfortunately, Glossy Buckthorn is invading many of our southeast Michigan fens. Recently we checked on a favorite fen, looking for invasive species. Thankfully, none were found but we had a reason to explore the fen for several hours.

Cambarus polychromatus

Paintedhand Mudbug

Walking into the fen on a narrow trail Joyce came across a crayfish. It stood defiantly in the center of the trail, reared up on its tail, pincers waving, antennae flexing through the air. Joyce got her walking stick too close and the crayfish lunged at it. Joyce stepped over him and the crayfish spun to face me. I felt as if I was Tolkien’s Balrog facing a mini lobster Gandolf. “You cannot pass.” [Note: It is only in the movie that he says, “You shall not pass.”] As I stepped over him, he charged my boot. I looked back and he was still guarding his path.

Physocarpus opulifolius

Ninebark

Ninebark (Physocarpus opulifolius) flowered along the trail holding some of its flower clusters at shoulder height. Five-petaled flowers, lobed sepals united at their bases to form a calyx tube, and its many stamens tell me that this is a member of the Rose Family (Rosaceae). Half spherical clusters of white to pinkish flowers with petals dotted in black result in this being one of our showier native shrubs. Its exfoliating (separating into layers) bark is said to give rise to the common name although I have never seen one with nine layers. Another explanation is that it is a corruption of the German word “nein” meaning no. “No bark” better explains the look of this plant.

Cypripedium reginae

Showy Lady-slipper group with last years seed capsules L Closeup of flowers R

A Showy Lady-slipper (Cypripedium reginae) blossomed under a Ninebark. It is our largest native orchid and this plant stood 2 feet (.6m) tall. A pair of flowers topped the plant; one at its prime, emitting a faint vanilla scent, and the other fading. We saw approximately 150 plants. A few Lady-slippers were past flowering, 50 non-blooming, 50 flowering, and 40 in bud. It is a healthy population.

Rhamnus alnifolia

Alder-leaf Buckthorn

Rhamnus-alnifolia

Alder-leaf Buckthorn showing fruit and flower

Our native Buckthorn, Alder-leaf Buckthorn (Rhamnus alnifolia) grew in two small colonies, one with three stems and the other with six. Alder-leaf Buckthorn seldom forms large stands and is not invasive like Glossy or European Buckthorn is. Toothed, strictly alternate leaves, with branches never tipped with spines, characterize Alder-leaf Buckthorn. This plant is seldom over 3 feet (1m) tall. I have seen plants cut and poisoned by over-zealous invasive species hunters. Anyone working to eradicate our invasive Buckthorns should learn to distinguish this native species.

Toxicodendron vernix

Poison Sumac

Poison Sumac (Toxicodendron vernix) flowered in a low, wetter, section of the fen. Shiny leaflets, red petioles, and gray bark are characters of this tall shrub. Urushiol oil, the same oil as Poison Ivy has, is found in all parts of the plant and many people are allergic to it.

Fens are delicate environments and require monitoring for invasive threats. Monitoring provides a great excuse to spend a few hours poking around outdoors.

I later learned that Michigan has eight to ten species of crayfish and this one is a native named Paintedhand Mudbug (Cambarus polychromatus). Crayfish Ontario, part of the Bishops Mills Natural History Centre has a nice guide for Crayfish identification. Mael Glon from Ohio State University corrected an earlier misidentification of this crayfish. Checkout his Crayfishes of Michigan page. Thanks Mael.
Copyright 2015 by Donald Drife

Revised March 2018

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Michigan Lady-slippers

Stemless Lady-slipper

Stemless Lady-slipper
Cypripedium acaule

The five species of Lady-slippers that grow in Michigan are some of our showiest wildflowers. They belong to the Orchid Family (Orchidaceae) and are in the genus Cypripedium. Cypripedium comes from Cypris meaning Venus and pedilon meaning shoe. Scientific names consist of two words. The first is the genus and the second is the specific name. Related plants are grouped in the same genus but have distinct specific names. Species are sometimes further broken down into subspecies, varieties, and forms. Our Yellow Lady-slipper has two varieties in the state, but it is difficult at times to distinguish them.

Stemless Lady-slipper

Stemless Lady-slipper
Cypripedium acaule

Stemless Lady-slipper (Cypripedium acaule), also called Moccasin Flower or Pink Lady-slipper, is a widespread acid loving plant. Acaule means stemless and refers to the leaves at the base of the plant. It flowers from late May and to the end of June. Normally the flowers are pink but white flowered plants and darker flowered plants occur. The flowers are cream-colored when they are developing and can be mistaken for albinos. It grows in the pine-needle duff around Grayling. Once we were looking for Moonworts (Botrychium spp) and stumbled onto several thousand lady-slipper plants blooming in a borrow pit. A borrow pit is a location were sand has been dug out for road construction. The area was less than an acre and the leaves of the plants touched each other.

Ram's Head

Ram’s Head
Cypripedium arietinum

Ram’s Head Lady-slipper (Cypripedium arietinum) grows in the Great Lake’s dunes or among the conifers at the edges of the dunes. Arietinum means like a ram’s head and the flower when looked at head on does resemble a head. The plant has a wiry stem that always seems to be moving in the breeze. It is a challenge to photograph this plant. Most recent records come from the Upper Peninsula and the Lower Peninsula north of Grayling.

White Lady-slipper Cypripedium candidum

White Lady-slipper Cypripedium candidum

White Lady-slipper (Cypripedium candidum) is found in fens or bogs in southern Michigan. Candidum means white. When I first saw this plant, I was surprised at its small size. The plant’s white lip has purple veins. This orchid loves sun and disappears where it is shaded. Several of the colonies I have observed for many years grow near railroad tracks and the fens burn periodically from fires caused by sparks from the railroad. Several colonies I know have been overgrown by Glossy Buckthorn (Frangula alnus [Rhamnus frangula]). One in Livingston County disappeared in five years. The first year several buckthorn seedlings grew among the flowering lady-slippers, by the third year the plants no longer flowered and were reduced to seedling like plants consisting of a single leaf. By the fifth year no plants could be located.

Yellow Lady-slipper

Yellow Lady-slipper
Cypripedium parviflorum var.pubescens

Yellow Lady-slipper (Cypripedium parviflorum) is found throughout Michigan and is highly variable. Parviflorum means small flowered. The species as now classified separates our plants from the European (C. calceolus) plants. The typical variety (var. parviflorum) occurs in the southeastern United States.

As a side note: when botanists name a new species of plant, they designate a “type specimen.” This is a single pressed plant that other botanists can study to determine exactly what the species is. The type specimen of a given species also establishes the typical variety that might not be the commonest variety. Therefore, the typical variety of the Yellow Lady-slipper is Cypripedium parviflorum var. parviflorum even though there are many more plants of the variety pubescens in the world. The variety pubescens (meaning pubescent) and variety makasin (from the Algonquin Indian name of this flower) both grow in Michigan.

Variety makasin has the common name Smaller Yellow Lady-slipper. In this variety the lip is small (the size of my little fingernail), the sepals and lateral petals are dark, it grows in bogs or fens in southern Michigan. This orchid is one of the sweetest smelling native plants with a strong scent similar to vanilla, another orchid.

Yellow Lady-slipper

Yellow Lady-slipper
(L) Cypripedium parviflorum var.pubescens
(R) Cypripedium parviflorum var. makasin

The variety pubescens is normally large, its lip shape, twisting and color of the lateral petals, and habitat are extremely variable. The Yellow Lady-slippers growing farther north than Saginaw are this variety but it also grows in the southern part of the state. Small plants of this variety can be difficult to distinguish from var. makasin. In some plants, the lips are cream colored. These plants are found well north of the White Lady-slipper so they are not hybrids. They are just color forms. Plants can be as tall as two feet (.6 m).

Showy Lady-slipper (Cypripedium reginae) grows in wet areas throughout the state. Reginae means “of the queen.” The plants are two to three feet tall, with one to three, two-inch wide flowers. They are regal plants. Botanists possess large vocabularies of technical descriptive words, however; Merritt Fernald in the eighth edition of Gray’s Manual calls this plant “handsome,” and in the first edition, Asa Gray himself calls it “beautiful.”

Showy Lady-slipper

Showy Lady-slipper Cypripedium reginae

The group of plants shown in the photograph grows in a ditch along U.S.2 in Michigan’s Upper Peninsula. I first observed the colony in 1973. I have never failed to find plants there but some years they are single leaves only a few inches long. When the trees grow up and shade the plants they stop flowering and gradually reduce in size. The power company clears the trees out of the ditch and within a year or two the plant bloom again. After five to ten years hundreds of plants flower in the ditch. As the trees grow up the number of flowering plants is reduced. Last year about a
dozen plants flowered. The trees were touching the power line so hopefully they will be cut soon.

I have watched another station for this plant almost as long. It grows in the Bald Mountain State Recreation Area in Oakland Co. When I first saw the colony in 1974, over six-thousand plants were flowering. It is in a large, cedar swamp. White-tailed Deer bedded down on grassy hummocks. When the deer population was high, they kept the White Cedar (Thuja occidentalis) browsed. When the deer population went down, the cedars grew up, shaded the plants, and they ceased flowering. The deer provide another service for the plant by stepping on their seedpods and planting the seeds. I revisited the colony a few years ago knowing that the deer population was high and expecting to see a lady-slipper show. I could only find a few single leaf plants. The cedar swamp was over-grown by Glossy Buckthorn (Frangula alnus). The colony is now gone.

An additional species, Franklin’s Lady-slipper (Cypripedium passerinum), occurs on the north shore of Lake Superior. It might one day be discovered in Michigan. I have often wondered if Oliver Farwell’s White Lady-slipper record in the 1880s from the Keweenaw was this species. His existing specimen is clearly White Lady-slipper but we know he replaced a few of his older specimens. I think he originally found Franklin’s Lady-slipper, identified it as White Lady-slipper because it was the only white-flowered lady-slipper in his botanical manual. Later he replaced the Franklin’s Lady-slipper specimen with the White Lady-slipper specimen that is the pressed plant we have today. Franklin’s Lady-slipper should be looked for in the Upper Peninsula. Who knows, one day, one of us may be walking alongside a cold northern Michigan stream…

Copyright 2013 by Donald Drife

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