Flora of the Sleeping Bear Dunes National Lakeshore

This past summer was a real treat for your blogger who got to do quite a bit of travelling and botanizing throughout Ohio and the surrounding states.  Back in mid July I found myself in northern Michigan in the Sleeping Bear Dunes National Lakeshore, recently voted the most beautiful place in the country.  I have spent some time in the region just about every summer of my life with my family and have great memories of the lakes, beaches, and atmosphere of Lake Michigan and the Grand Traverse area.  As the years have gone by and my interest in botany and the natural history increased, I've found myself spending more and more of my vacation time exploring the varying habitats and ecosystems of the northern woods and Great Lakes.

Sleeping Bear Dunes National Lakeshore, Leelanau Co., Michigan

Despite looking bleak and desert-like, the world-famous sand dunes along the shores of Lake Michigan in Leelanau county are full of fascinating plant life; some of which is quite rare and found few other places.  I'd like to share some photographs of the flora I found most interesting and best represents these globally significant dune ecosystems, which are disappearing more every day to development and habitat destruction.

Spotted Horsemint  ~  Monarda punctata

One of the first plants I noticed growing in massive colonies throughout the higher ridges and bluffs was the spotted horsemint (Monarda punctata).  It is also known as spotted beebalm and comes from the mint family (Lamiaceae).  This mint is quite rare back in Ohio and is currently state-listed as an endangered species but is the farthest thing from further north in Michigan.  It's almost weed-like in just about every dry, sandy meadow or field.

Spotted Horsemint  ~  Monarda punctata

I had long wanted to see the interesting combination of its pale green to lavender leaves and lemon-yellow flowers spotted with purplish-red dots.  Being a mint, it's not hard to believe this wildflower smells as good as it looks.  Being so frequent throughout the area I decided to pick a bouquet of the horsemint that would grace our kitchen counter top all week, giving the room a fresh and spicy scent.

Pitcher's Thistle  ~  Cirsium pitcheri

One of the most exciting, and over-looked, plants that calls the dunes home was the federally threatened Pitcher's thistle (Cirsium pitcheri).  I've blogged about this species before in the past that you can read right here.  This true rarity is an endemic of the Great Lakes and can only be found in high-quality, intact dune habitats along the shores of Lake Michigan and Lake Huron.

Pitcher's Thistle  ~  Cirsium pitcheri

Each thistle begins its life as a small rosette of blue-green basal leaves with a deep taproot that allows it to survive in such a dry habitat.  The rosettes mature between two to eight years before suddenly sending up flowering stalks one year and bloom throughout the summer months before dying and setting to seed.  Pitcher's thistle is monocarpic, meaning each individual plant only flowers and fruits once in its life before dying.

Pitcher's Thistle  ~  Cirsium pitcheri

Taking a glance at the flower heads it's not much of a stretch to immediately recognize this as a Cirsium species.  It's white-colored phyllaries are uniquely colored for a thistle and when combined with its equally unique habitat it's not hard to come up with a specific ID.

Bearberry  ~  Arctostaphylos uva-ursi

You'll notice a trend throughout this post that many species included are quite rare in my home state of Ohio.  Michigan has a significant advantage over Ohio in the available habitat department with over 3,000 miles of Great Lakes shoreline compared to Ohio's 300 or so.  While both states share many of these same shoreline and dune obligate species, Ohio's limited habitat has been largely lost as has the native flora.  Michigan has seen its fair share of habitat loss but still has more remaining and intact than Ohio probably ever had.

Bearberry  ~  Arctostaphylos uva-ursi

This lovely creeping plant could be found in large amounts, carpeting the drier, higher dunes with its evergreen, thick-leaved foliage and mealy red berries.  Bearberry (Arctostaphylos uva-ursi) comes from the heath family (Ericaceae) and produces small white, bell-like flowers in the spring that become the bright red fruits you see here by summer.  I suspect the namesake of this plant is from reported bear's desires to eat the mature fruit but after trying one for myself I can say it would be among my last and most desperate of food sources.

Sand dune habitat along Lake Michigan

The plant(s) with probably the most important task but the most easily ignored are the grasses.  Their network of roots and rhizomes help prevent the sand from shifting and eroding with the water, wind, and foot traffic and keep the dunes intact for other plants to survive and persist.

American Beachgrass  ~  Ammophila breviligulata

The most common species along the shoreline's margin was the American beachgrass (Ammophila breviligulata).   This species thrives in the rougher conditions along the shore and readily grows and spreads despite being hit with constant wind and waves.  It's the first line of defense for the sand dune's structural integrity but quickly fades out as you move further inland and away from the disturbance of the shoreline.

Beach Pea  ~  Lathyrus japonicus

Mixed in among the beach grass were copious amounts of the beach pea (Lathyrus japonicus) growing right out of the stabilized sand.  This species has an interesting North American distribution and is only found along the shores in the Great Lakes region; New England seaboard; and the Pacific Northwest.  It can be readily identified by its striking purple and white flowers with the classic pea/legume look and the arrow-shaped ligules where the leaves meet the stem (best seen in the photo below).

Beach Pea  ~  Lathyrus japonicus

The beach pea is a circumpolar species and grows in the temperate coastal areas of North and South America, Asia, and Europe.  It owes its global distribution to its seed's fascinating ability to remain viable for five years while floating on the ocean's currents.  It would be interesting to test the genetics and DNA from populations all over the world and try and figure out the species' origins and paths of migration, if it hasn't been done already.

Ancient white cedar skeleton log 

One of the most interesting aspects to the dynamic dune landscape is the ancient skeleton logs belonging to long-deceased white cedar (Thuja occidentalis) trees.  White cedar wood is extremely rot-resistant and the sun bleached, wind and sand smoothed logs scattered throughout the dunes make for a neat aesthetic touch.  The exposed specimen above could be over a century old and recently re-revealed to the world by the ever-shifting sand.

Silverweed Cinquefoil  ~  Argentina anserina

A common wildflower that dots the shorelines during the summer months is the silverweed cinquefoil (Argentina anserina), which takes advantage of the soft, sandy habitat and spreads by its red stolons.  It gets the name silverweed by the leaves silver-colored undersides, which in retrospect I wish I would have photographed!  They look like some vandal gave the leaves ventral sides a coat of silver spray paint.

Kalm's St. John's-wort  ~  Hypericum kalmianum

Walking further inland along the dune swales and blowouts, the gorgeous yellow-flowered shrub Kalm's St. John's-wort (Hypericum kalmianum) became quite common and was a stunning scene in full bloom.  This species is largely restricted to the Great Lakes region and is rare in Ohio where it only occurs in the northern counties near and along Lake Erie.

Huron Tansy  ~  Tanacetum huronense

This wildflower species would certainly not win any awards for its looks but it certainly deserves your respect for its rarity and fascinating natural distribution.  In a few, select areas of dune habitat in the Grand Traverse area is the threatened Huron Tansy (Tanacetum huronense).  Unfortunately, once I was able to luckily come across some it was already well past flower and only the dried heads remained.  In fact, out of the hundreds of vegetative plants I found, the one pictured above was the only specimen that flowered this summer.  Looking at a range map for this species shows its curious distribution.  It is only found in a handful of northern-most LP counties and eastern UP counties of Michigan; extreme northern Maine; and then is absent from the rest of country except for the northern half of the Pacific coast.  There's a few other species that have a similar disjunct distribution in the northern Great Lakes and Pacific northwest and I'm curious to know more on the 'whys' of the matter.

Old red pines (Pinus resinosa) in a mixed conifer forest

After thoroughly exploring the sand dune habitats, I wandered further inland into some impressive mature pine forests that had some of the largest red pine (Pinus resinosa) and white pine (P. strobus) specimens I'd ever seen.  The understory was an unbroken sea of bracken fern (Pteridum aquilinum) that seemed to stretch out in all directions and thrive in the sandy, acidic soils.  In the lower pockets and areas of the woods were more moist and saturated soils containing white cedar thickets and swamps that housed some stunning wildflowers still showing off their blooms.

Clump of well-past flowering Showy Lady's-slipper (Cpyripedium reginae)

As my eyes scanned the surrounding vegetation my attention was caught on a cluster of very familiar leaves I knew I had seen before.  My heart skipped a beat as it quickly set in I had stumbled across some past-flowered showy lady's-slippers (Cypripedium reginae).  If only I was in this exact spot a few weeks earlier and had been able to make this group's acquaintance while in full bloom.  It never, ever get's old seeing this spectacular orchid in its prime.

Cardinal flower  ~  Lobelia cardinalis

Not far from the showy lady's-slippers was a sun-drenched opening in the cedar swamp that immediately stood out due to the scarlet red wands of cardinal flower (Lobelia cardinalis) coming into bloom.  It's hard not to notice the most brilliant red color in the plant kingdom set against the green of the cedars and marsh fern (Thelypteris palustris).

Cardinal flower  ~  Lobelia cardinalis

A closer look at the striking blooms of the cardinal flower can only make the heart grow fonder of the plant.  It's a favorite of the hummingbird, which in turn is one of the plant's only pollinators.  If you have a rain garden or a spot on your property with regularly moist and rich soil you couldn't go wrong with planting some of this wildflower.

Fireweed  ~  Chamerion angustifolium

Yet another striking summer wildflower of the northern woods you can't miss is the fireweed (Chamerion angustifolium).  Quite rare in Ohio, it becomes much more common in the northern states and especially in the mountain west where I've seen it by the thousands in Glacier National Park.  The flowers don't last very long and are pollinated by a slew of insects and is a much-desired honey plant that honeybees absolutely love.  Speaking from experience, fireweed honey is a delicious alternative to the traditional clover variety.

Federally endangered Michigan Monkeyflower (Mimulus michiganensis)

As I returned back to where we were staying I decided to make a quick pit stop to see one of the world's rarest plants and a federally endangered species I blogged about last summer, the Michigan monkeyflower (Mimulus michganensis).  This small seep emitting from the hillside flows right down to the shore of Big Glen Lake and provides the specific habitat niche this rarity needs to survive.  The small, yellow snapdragon-like flowers were starting to wane but still in well enough shape to snap a photo or two.  If interested you can go back and read the dedicated post to this species' amazing story right here.

Living in southeastern Ohio it's not often I find myself in the incredible and diverse habitat of the Great Lake's shorelines and dunes, so I like to take full advantage of the little time I do get during the summer.  The flora is so strikingly different from what I see on a day to day basis and the dunes are home to some of the more rare and unique plants one can find.  I'm already looking forward to my feet in the wet sand and chilled waters of Lake Michigan next year.