Welcome to the Christmas month.

When you take a walk in December’s woods you’ll find very little green except for this plant, the Christmas fern, Polystichum acrostichoides, so named because it’s green during the holidays.

Christmas fern is a common, evergreen, perennial fern that grows in the woods in most of eastern North America.  It’s one of the few ferns I can recognize because its leaflets are shaped like Christmas socks or like Santa’s sleigh.  (To see the sleigh shape turn the leaflet sideways with the “thumb” pointing up.)   From afar the plant looks like a clump growing in well-drained rich soil.

People used to use this fern in Christmas decorations, though I must say I prefer pine for its Christmas-y smell. 

Keep your eyes open for this splash of green.  It brightens December’s short days. 

(photos by Dianne Machesney)

Oriental Bittersweet (Celastrus orbiculatus), native to Asia, captured the hearts of American gardeners in the 1870s.  What an ideal plant it seemed, with gorgeous red berries that appeared just in time for festive holiday decorations.

Unfortunately it escaped to the wild and is now an invasive vine that thickly covers our native plants.  It spreads easily because its fruit tastes good to birds and is now listed as invasive in 21 states and 14 national parks.  What a mistake!

And yet, it is beautiful.

(photo by Dianne Machesney)

Plants have many strategies for dispersing their fruits. Here’s one that’s quite ingenious.

First, wrap the seed in a very sour, very hard pulp.  Then wrap the pulp in a colorful covering that lasts a long time.  The fruit is so hard and sour that no one will eat it.  So why bother making fruit?

Ah, but wait.  As fall turns to winter, frost breaks down the pulp and takes the extreme sour edge off the fruit.  At this point the birds who remain through the winter have something to eat.

Theoretically this strategy of feeding winter birds would guarantee the seeds don’t disperse far, but the plant has spread thanks to people.  In colonial times we figured out how to add sugar and make jams and jellies from it, and we like its color so much that we plant it as an ornamental.

Quite a success story for Cranberry Viburnum (Viburnum trilobum), a beautiful but sour fruit.

(photo by Tim Vechter)

Sometimes the best fall colors come in tiny packages.

Look at the forest floor and you may see this Indian Cucumber.  It’s all decked out in green, red and blue to attract passing birds.  The colors are arranged like a bull’s eye, circling the berries.  “Eat me!” it says to the birds.  And they oblige.

(photo by Dianne Machesney)

No, these aren’t tomatoes.  They’re related to tomatoes, but don’t eat them.  They’re poisonous.

These are the fruits of Bittersweet Nightshade (Solanum dulcamara), a common weed in North America that’s native to Europe and Asia.  Click on the photo to see its flowers.

Until I did the research for this blog, I called this plant Deadly Nightshade but that’s the common name for a completely different and far more deadly plant, Atropa Belladonna.  Belladonna is so poisonous that 2-5 of its deep blue berries can kill a child, 10-20 berries or a single leaf can kill an adult. In Ancient Rome the aristrocracy found it quite effective for killing their rivals.

Both plants are in the Nightshade family (Solanaceae) which includes a wide variety of edible and poisonous species.  The edible plants are so tasty that humans went to the trouble of cultivating them: potatoes, tomatoes, eggplants, chili peppers and paprika.  The toxic plants are beautiful but dangerous: Deadly Nightshade, Bittersweet Nightshade, Mandrake and Jimson Weed (Datura), to name a few.

Somewhere in humanity’s past, people had to figure out which plants were good to eat and which weren’t.   What a risky business!  I’m glad that job is done and we’re able to pass on the knowledge.

Meanwhile, don’t worry that you’ll mistake these berries for tomatoes.  Bittersweet Nightshade berries are tiny and the plant smells bad.

(photos by Chuck Tague)