In Search of Something Green (and Native)

American holly (Ilex opaca) on the Cabin John Trail


After two weeks battling a sinus infection, I finally felt well enough to go for a hike. Well, more of a walk. As I’ve written before, the Cabin John Trail is treacherous: an over-used trail with poor footing in many places. But, I almost always find something worthwhile, if I take the time to poke around and really look at things.

And so it was yesterday. I knew I’d find a lot of Christmas fern, but went with the goal of finding something else – and I did, after scrambling about in a dryish seasonal watercourse. Look for a post about that fern in another few days.

After that I went to a section I call Erica Alley. It’s a very rocky slope with a high concentration of mountain laurel (Kalmia latifolia), and big stands of rock polypody. There I found several small stands of spotted wintergreen (Chimaphila maculata, another ericaceous plant), which thrills me because I failed to find it near Carderock this year. And then, poking about, I found something completely new. And something old that required re-inspection.

I don’t carry ID books with me. Whenever I have a book, I end up plopping my butt down and reading for 20 minutes. I’m too easily distracted by “dictionary syndrome”. So I take pictures, but often fail to get the right pictures for a definitive ID. At least I’ve narrowed them down to the correct genus. Perhaps if the weather’s good today I’ll go out again, this time with the ID books, dammit.

If you see a middle-aged woman reading a book on the Cabin John Trail, say hi.

Many Little Feet


Common or rock polypody, American wall fern, rockcap fern
Polypodium virginianum

a small stand on the Cabin John trail


This little fern is no less charming for being incredibly common.  It’s found throughout most of the eastern US and Canada except for parts of the deep south.  Although short (the fronds are usually about twelve inches long), the rhizomes will form massive colonies in suitable habitat, which consists of all sorts of rock outcroppings and rocky soils in moist shade.



an itty-bitty specimen at Carderock; it doesn’t have much soil to grow in!


It’s also an easy fern to identify, especially at this time of year, since it’s evergreen.


new fronds in late April along the Cabin John trail

Oh, Christmas Fern


Polystichum acrostichoides
Dryopteridaceae (wood fern family)

specimen showing sterile and fertile fronds; pardon the boot!

If you’ve been walking around the woods during this freakishly warm season, you’ve probably seen Christmas fern, a widespread evergreen fern of moist to dry woodlands that’s found all over the eastern part of North America.  It’s a lovely plant for the garden, with glossy dark fronds adding winter interest, and a tidy, clump-forming habit.



young frond in July




Christmas fern stands about two feet tall, and is easily identified (especially in winter). Each pinna has a distinctive upward-pointing lobe near the base, variously described as a thumb, or toe, or ear. (The technical term is auricle, meaning ear-shaped lobe.)

The fertile fronds have a distinctive shape, with the sori-bearing pinna becoming shorter, narrower, and more widely spaced on the upper portion of the fronds:









sori on underside







crozier in July



ps: please refer to my posts about fern terminology and fertile fronds for definitions of some of the jargon