Archive for the 'Plants' Category

Jul 07 2015

The Sneaky Little Vine: Dodder

Published by under Plants

Dodder vine wrapped around a stem (photo by Kate St. John)

Dodder vine wrapped around a stem (photo by Kate St. John)

This small yellow-orange vine is a native member of the morning glory (Convolvulaceae) family that’s hated by agriculture.

Dodder (Cuscuta) has virtually no leaves and is not green because it doesn’t use chlorophyll to make food.  Instead it wraps itself closely around a host plant, inserts very tiny feelers (called haustoria) between the cells, and sucks nutrients out of the host.  Though it starts growing from seed, it loses its soil-based roots when it’s found a really good host.

Newcomb’s Wildflower Guide has only one entry for dodder in eastern North America — common dodder (Cuscuta gronovii) — but there are 100-170 species around the world, especially in tropical and subtropical climates.

In Pennsylvania dodder blooms summer and fall in dense clusters of small white flowers.  According to Wikipedia “the seeds are minute and produced in large quantities. They have a hard coating and typically can survive in the soil for 5–10 years, sometimes longer.”  And therein lies the problem.

Farmers hate this plant because it eats some of the plants we cultivate.  Tomatoes, for instance.  If dodder takes over the best way out is to plant something dodder can’t live on — grasses or wheat — but it takes a few years before the dodder seed bed is too old to grow.  Hence, dodder has been declared a noxious weed/seed in 49 states.

On the other hand, I’ve rarely seen dodder take over (here’s what a thick patch looks like) and tomatoes have developed their own defenses against it.

In the end you might think dodder is good for nothing but in western North America it hosts the caterpillars of the brown elfin butterfly (Callophrys augustinus). (See comments.)

And so goes the circle of hosts.  It’s eat and be eaten.


(photo by Kate St. John)

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Jul 05 2015

Pretty. Invasive.

Published by under Plants,Schenley Park

Purple loosestrife blooming on CMU's campus, 2 July 2015 (photo by Kate St. John)

Purple loosestrife blooming on CMU’s campus, 2 July 2015 (photo by Kate St. John)

When I saw this plant blooming in Schenley Park the other day I made sure to point it out to participants at last Sunday’s walk.  Most people aren’t aware that purple loosestrife (Lythrum salicaria) is highly invasive.

Purple loosestrife came to North America from Europe and was established on the east coast by the mid 1800s.  It grows 1.5 to 5 feet tall with opposite or alternate untoothed leaves and a spike of pinkish purple flowers. Here’s a closeup of the flower.

It spreads by seed and by massive woody roots in ditches, wet meadows and wetlands.  Once it takes hold it out-competes native plants and creates a monoculture that lowers the biodiversity of the site.  Amazingly it even affects ducks because, though dense at the top, it’s open at water level and provides no cover for nesting.

Purple loosestrife is listed as invasive in 27 states, including Pennsylvania, but many garden stores and garden websites still sell it to those who are unaware of the danger.  When its seeds get into flowing water, watch out!

Fortunately years of research found a beetle that eats it.  In the video below, Donna Ellis from the University of Connecticut Cooperative Extension describes purple loosestrife and how the Galerucella beetle is an effective biological control agent. (Birders, listen to the audio track. If I’d been standing there I would have been totally distracted by those upset birds!)

I found only a single loosestrife in Schenley Park and an Urban Eco Steward pulled it up (yay!) but on Thursday I found two clumps on Carnegie Mellon’s campus.  Uh oh!

Pretty.  Invasive.


(photo by Kate St. John)

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Jun 28 2015

Deep Purple

Published by under Plants

Clemantis at Phipps Outdoor Garden (photo by Kate St. John)

Clemantis at Phipps Outdoor Garden (photo by Kate St. John)

I don’t usually write about cultivated flowers but these caught my eye at Phipps Conservatory’s Outdoor Garden.

A Google Image search matched my photo to Clematis jackmanii, a cultivar introduced in 1862 by George Jackman.  Phipps Conservatory was built in 1893 so the plant and the building would be close contemporaries.

The vine is thick with 5-7″ deep purple flowers.

Clemantis vine at Phipps Outdoor Garden (photo by Kate St. John)

Clemantis vine at Phipps Outdoor Garden (photo by Kate St. John)

It also has these unusual swirling structures.    Do you know what they are?

Clemantis vine at Phipps Outdoor Garden (photo by Kate St. John)

Clemantis vine at Phipps Outdoor Garden (photo by Kate St. John)


(photos by Kate St. John)

p.s. If I’ve misidentified the vine, please let me know!

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Jun 24 2015

Wet Weather Brings …

Tuliptree with anthracnose, Schenley Park, 22 June 2015 (photo by Kate St. John)

Tuliptree with anthracnose, Schenley Park, 22 June 2015 (photo by Kate St. John)

At the end of May I lamented that my backyard was dry and cracked while 27 counties in Pennsylvania were under a Drought Watch.

Conditions have changed significantly.

From a May rain deficit of 1.23 inches, Pittsburgh now has a surplus of 2.00″ in the first 23 days of June. (Normal in Pittsburgh is 3.95″ for May and 3.30″ to the 23rd of June.)  Yes it’s wet!

Around western Pennsylvania it’s wet elsewhere, too.  New Castle got 2.32″ in yesterday’s storms alone!  Johnstown is 6.5″ above normal for the month (300% of normal) and Dubois stands at 1.85″ above normal for June 23.

The wet weather has caused flash floods, flooded basements and another more subtle problem:  fungus.

On Monday I noticed that the tulip trees in Schenley Park and at Phipps’s outdoor garden have brown curled leaves at the top.  Worried that we had another forest pest on our hands I emailed this photo to Phil Gruszka, my favorite tree expert at the Pittsburgh Parks Conservancy.  He says its anthracnose.

Anthacnose is a group of fungi that infect shade trees, usually browning their leaves but sometimes infecting their twigs, bark and fruit.  Each tree species has its own specific fungus pest.  The one that infects tulip trees attacks the leaves.

In large stands of trees there’s no practical treatment for anthracnose.  Though it may weaken the trees it doesn’t kill them outright and they get a respite if the weather changes.  The fungi go away when it’s dry.

When will it be dry?  … Do we dare ask that question?


p.s. Libby in New Castle, Marianne in Dubois area, and Marcy in Indiana County, how’s the weather out there?

(photo by Kate St. John)

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Jun 14 2015

Now Fruiting: False Solomon’s Seal

Published by under Plants

Fruit of False Solomon's Seal (photo by Kate St. John)

Fruit of False Solomon’s Seal (photo by Kate St. John)

In June there’s a blooming hiatus between Spring’s woodland wildflowers and field flowers in July.  The plants I notice this month are the ones in fruit.

Here’s a woodland plant that bloomed last month.

False Solomon’s Seal has set fruit but it isn’t ripe yet.  In the fall its berries will be red.

Click here to read more about it and see what the plant looked like in bloom.


(photo by Kate St. John)


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Jun 07 2015

Color With Thorns

Published by under Phenology,Plants

Nodding thistle flower head (photo by Kate St. John)

Nodding thistle flower head (photo by Kate St. John)

Lots of big thistles are blooming now by the road to Duck Hollow in Pittsburgh.  At first I couldn’t identify them but my guess was that anything growing so well by the road was probably alien and invasive.  I was right.

Nodding thistle or musk thistle (Carduus nutans) is a biennial from Africa and Eurasia that came to this continent by accident, perhaps in ballast water.  It thrives in disturbed soil at roadsides and landslides and in heavily grazed pastures.  It’s a thorn in the side for cattle farmers and an alien invasive.

A view of the entire plant shows many thorns and the reason why its called “nodding.”

Nodding thistle nods (photo by Kate St. John)

Nodding thistle by Old Browns Hill Road (photo by Kate St. John)

Despite its mean reputation, I think it’s beautiful. The buds look like reddish-purple star bursts as they open.

Nodding thistle bud opening (photo by Kate St. John)

Nodding thistle bud opening (photo by Kate St. John)

And the color of the flower is outstanding. My favorite view is too wide for this blog’s narrow format so click here for a closeup of color without thorns.


(photos by Kate St. John)

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May 31 2015

Named For A Dogs’ Body Part

Published by under Plants

Houndstongue, Ohio's Lake Erie shore, 16 May 2015 (photo by Kate St. John)

Cynoglossum officinale, Ohio’s Lake Erie shore, 16 May 2015 (photo by Kate St. John)

And now for something completely different.  This morning I’m taking a break from peregrines to tell you about an unusual name.

I found this plant blooming on Lake Erie’s sandy shore at Magee Marsh, Ohio this month.  It took me a while to identify it because it’s non-native.

Houndstongue (Cynoglossum officinale) is native to Eurasia but was accidentally introduced to North America where it happily grows in waste places.  It’s been spreading for so long that Michigan declared it one of the worst weeds in the state more than 100 years ago.  This one was growing just across the lake from Michigan.  Perhaps it migrated to Ohio.

The plant is twice-named for a dog’s tongue: “houndstongue” and cyno (dog) glossum (tongue).  Theoretically, if you put a houndstongue leaf in your shoe no dogs will bite you, but that outcome is statistically likely even without the leaf.

If I’d crushed a leaf I would have noticed the plant smells bad — like “rats and mice” — which is one of its nicknames.  Nonetheless people have used it as a cure for baldness, hemorrhoids, respiratory problems, and madness.   There’s no proof that it heals but it will make you sick.  Houndstongue contains cancer-causing pyrrolizidine alkaloids, toxic to the liver and to livestock.

Be careful when you put that leaf in your shoe.


(photo by Kate St. John)

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May 24 2015

Field Of Dreams

Published by under Plants

Dandelions gone to seed (photo by Kate St. John)

Make a wish and blow on the dandelion fluff.

Click on the photo to see a dandelion Field of Dreams.


(photos by Kate St. John)

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May 05 2015

Leaf Out!

Red oak leaves, 1 May 2015 (photo by Kate St.John)

Last weekend’s new leaves in Schenley Park demonstrated that the city is warmer than the suburbs.  Schenley’s leaves unfurled on May 1 while the suburbs were still brown.

Above, new red oak leaves. Below, sugar maple.

Sugar mapleleaf-out, 1 May 2015 (photo by Kate St. John)

This white ash sapling opened its leaves like a crown.  Tiny ash saplings aren’t eaten by emerald ash borer because their stems are too narrow for the bug to use.
White ash leaf-out, 1 May 2015 (photo by Kate St. John)

For dramatic leaf-out, you can’t beat a shagbark hickory.  This bud was just about to unfurl …
Shagbark hickory, leaves about to open, 1 May 2015 (photo by Kate St. John)

And … Boom!
Leaf out! Shagbark hickory (photo by Kate St. John)

Three days later the leaves now produce shade.
Shagbark hickory leaves, 4 May 2015 (photo by Kate St. John)


Take a look at tree covered hillsides as you drive north or south and you’ll notice leaf-out moving north 13 miles a day — except in the city.


(photos by Kate St. John)

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May 01 2015

False Miterwort

Published by under Plants,Schenley Park

Foamflower blooming (photo by Kate St. John)

Foamflower blooming, photo by Kate St. John

Foamflower is one plant, Miterwort’s another, but I called a patch of Foamflower “Miterwort” during last Sunday’s outing in Schenley Park.

Perhaps that’s because one of Foamflower’s alternate names is “False Miterwort.”  I must have had that in mind when called it Miterwort. (Sure!)

The position of their leaves is the easiest way to tell the difference.  Though the leaves are the same shape, Foamflower has basal leaves, Miterwort has two leaves opposite each other in the middle of the stem.

Miterwort blooming (photo by Kate St. John)

Miterwort blooming (The plant is usually erect), photo by Kate St. John

A close look at the flowers also tells them apart. Foamflowers (Tiarella cordifolia) look fluffy or foamy (first photo).  Miterwort (Mitella diphylla) flowers have intricate lace edges like tiny bishops’ caps — or miters (second photo).

I know the difference but I persistently say the wrong name.

Maybe I’ll do better now that I’ve publicly embarrassed myself.  😉


(photos by Kate St. John)

p.s. Since last Sunday the deer have eaten the tops off half of those Foamflower plants.  Grrrr!

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