7 July 2015

This small yellow-orange vine is a native annual in the morning glory (Convolvulaceae) family that causes trouble for farmers.

Dodder (Cuscata) has virtually no leaves and is not green because it doesn’t have chlorophyll to make its own food.  Instead it’s a parasite that 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 has 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 July to October 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 including tomatoes.  If dodder takes over the best way to combat it is to plant something dodder can’t live on such as 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 act invasive in the wild (here’s a thick patch) 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.  Dodder eats from its host and, as a host, it is eaten.

(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.

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

(photos by Kate St. John)

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

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)

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.

p.s.  This plant was part of the three witches’ Brew in Macbeth. Shakespeare called it “tongue of dog.”

(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)