Black cohosh (Cimicifuga racemosa) is blooming now in Pennsylvania’s woods.  The flower is white, it’s the root that’s “black.”

The plants are three to nine feet tall topped by a spire of branching, fuzzy-looking flowers.  The spire makes up a third of the plant’s height and normally stands straight (this specimen is leaning) so the flowers appear to float high above the vegetation.

I encountered a large stand of Black Cohosh a week ago at Moraine State Park.  Amazingly, I didn’t notice it at first.  I bent over to identify another flower and when I straightened up I saw the cohosh everywhere like a ghostly army of flowers, white against the cool green of the forest.

Black Cohosh flowers look beautiful but they smell bad.  The purpose is to attract flies, gnats and beetles for pollination.

If you ever have a doubt about identifying this plant, take a whiff.  Eeeeew!

(photo by Chuck Tague)

Now that the weather is cooler the plants look happy again.

Here’s a picture from Marcy Cunkelman’s garden in Indiana County.

(photo by Marcy Cunkelman)

People think orchids are hothouse flowers but quite a few native orchids grow wild in western Pennsylvania.  The showiest are few and far between.  The inconspicuous are hard to find.

This Ragged Fringed Orchid (Platanthera lacera) grows in Allegheny County.

It’s usually overlooked because its flowers are a creamy green color.  The plant itself is two feet tall.

Cool fact: It emits its fragrance at night to attract Sphinx Moths!   Click here to read more.

(photo by Dianne Machesney)

One of the prettiest flowers you’ll see by the road at this time of year is one of the most aggressive, invasive plants in North America.

Crown vetch (Securigera varia) was introduced in the U.S. in the 1950’s during our interstate highway boom.  It was hailed at the time as a fast growing, drought resistant ground cover and planted extensively along the new highways to eliminate the need to mow.

Those same characteristics allowed it to smother the native plants it encountered in its path.

Crown vetch is native to Europe, southwest Asia and northern Africa.  It thrives in open, sunny places, spreading by seed and rhizomes.  It has no North American enemies, nor can it be eaten by farm animals or wildlife because it contains nitroglycosides which cause slow growth and paralysis if consumed in large amounts.

Sixty years after its introduction to America, crown vetch is listed as invasive in 45 states.  If you’ve ever tried to eradicate it you’ll know why.

I once planted a free seed packet of wildflowers in my front garden.  To my dismay the seed company included two — just two! — crown vetch seeds in the mix.  I let them grow that first year.

The next spring I was left with two perennials and two crown vetch plants.  I pulled the vetch and planted new flowers but the vetch reappeared in more places than I’d pulled up.  I weeded, it reappeared, over and over and over again. Yikes!

The only solution was to give up on the other flowers and aggressively pull out every crown vetch plant and its root as soon as it appeared.  It took two years of meticulous weeding before I eradicated the vetch from my small garden.

Sadly, the seed companies still sell crown vetch.

You can buy this pink invader … but DON’T!

(photo by Trisha M. Shears via Wikimedia Commons.  Click on the photo to see the original.)

Yes, Columbo, but I’m not referring to the disheveled detective played by Peter Falk. 

Last weekend I traveled to a secret meadow to find this enormous plant in bloom. 

American Columbo (Frasera caroliniensis) is a member of the Gentian family and endangered in Pennsylvania.  Some people call it Monument Plant, an obvious name when you consider my bright green walking stick in this photo is 3.5 feet tall.  The plant is huge!   (See better photos here.)

American Columbo has an unusual reproductive strategy.  It’s a monocarpic perennial that grows as a rosette of basal leaves for many years without flowering.  Then in response to an unknown trigger it shoots up a stalk 10 feet high, blooms and dies.  

When it will bloom is a mystery no one can predict by its size or age but botanists think individual plants may bloom synchronously with other Columbos nearby.  A solo plant transplanted by a botanist did not flower in 15 years of watching.  Was it lonely?

Do all the Columbos in a meadow bloom at once?  No.  The meadow has plants of different ages because Columbo seeds are fussy.  They won’t germinate until they’ve soaked up water when the temperature is about 40^o F (5^o C).  Seeds that remained in the old seed head must wait for the right conditions to occur when they reach the ground so they won’t germinate for another year or more. 

My visit to this mysterious plant ended in a bumbling detective adventure.  As I bushwhacked out of the meadow I dropped my bifocal sunglasses but didn’t discover my loss until I’d hiked another half hour.  I returned to the meadow to find them but I my path was obscured.  I couldn’t be sure I was retracing my steps. 

After a long search I found my sunglasses.  Broken.  Someone had stepped on them.  Who?  

Did I?  Yes, the sunglasses fell under my feet and I stepped on them just after they fell. 

Mystery solved.  Thanks, Columbo.

(photo by Kate St. John)

Heal-all (Prunella Vulgaris) may be a weed but it’s good for us.  Also known as Self-heal, it’s a medicinal plant with antibacterial qualities that treats a wide variety of illnesses.

Newcomb’s Wildlfower Guide doesn’t call it “non-native” because its presence in North America pre-dates known travel records.  Did it come here on its own or did people bring it?

Native Americans use heal-all as medicine so perhaps the first Americans brought it across the land bridge from Asia.  And now it’s here to stay.

Watch for Heal-all blooming throughout the summer.

(photo by Dianne Machesney)

6 June 2010

The annual onslaught has begun.  Canada Thistle is blooming in southwestern Pennsylvania.

Though we call it Canada Thistle, Cirsium arvense is badly misnamed.  Native to Europe and northern Asia, it’s now found as far away as Australia and New Zealand, and it’s never welcome.  It’s invasive nearly everywhere it grows.

Some of Canada Thistle’s other names are more descriptive:  Hard Thistle, Creeping Thistle, Cursed Thistle.  It spreads by seeds and through its “creeping” root system that extends horizontally for 15 feet or more.  Each plant produces only male or female flowers so a clump can be isolated and not be pollinated.  No matter.  It’s perennial, its roots spread, and it chokes out less aggressive plants.

Watch for Canada Thistle’s violet flowers by roadsides, in fallow fields and in disturbed sunny patches.  When you find it, there’s one bit of good news to keep in mind.  Canada Thistle provides food for Painted Ladies and American goldfinches.

Goldfinches nest when the thistle blooms.

(photo from Wikipedia. Click on the image to see the original.)

If you take a walk in the woods in May, you’ll often find a flower that resembles Lily of the Valley. 

Canada Mayflower (Maianthemum canadense) is in the lily family and occurs from the forests of Canada to the Appalachian Mountains in Georgia. 

Fortunately it’s not as aggressive as the Lilies of the Valley which have long since escaped my garden border and invaded the grass.

(photo by Dianne Machesney)