Evergreen Native Ferns

– Posted in: Native/Invasive
9 comments

It’s so easy to think that nothing is living or growing under the snow, but all you need is a January thaw and a stroll in the woods to see that there are plants that have not given in to the onslaught of cold and snow. On my strolls over the years I have noticed that there are two ferns that remain evergreen in our woods during the winter. The previous two days the high was 45Β°F and it rained for a good part of each of those two days, removing almost all of the snowpack. It would have been the perfect time to take photos of the ferns, but then last night it snowed and the ferns are somewhat obscured as a result.

I don’t know much about ferns

I know a fern when I see one, and that’s about it. I thought it was about time I taught myself a bit more. The first step is to learn the terminology, otherwise whatever you read in guide books or online makes no sense. I have William Cullina’s Native Ferns, Moss & Grasses which illustrates all the terms with photographs, but you can visit Fancy Fronds Nursery’s glossary for a quick review. Join me as I try to identify these two ferns.

Christmas fern

polystichum acrostichoides Christmas fern

Christmas fern, Polystichum acrostichoides, is so named because it’s been used for holiday decorations.

If you wish to use it this way, Cullina advises that you only remove one or two fronds from each clump or you will weaken the plant. Likewise, in a garden setting, don’t cut down last year’s fronds until the new ones have expanded and the old ones have withered.
Christmas fern in the snow

Here’s what one Christmas fern looked like today.

Christmas fern fronds are pretty distinctive, and since it’s one of the few evergreen ferns native to northeast North America, I’m pretty sure I’ve identified it correctly. The identity of the next fern is more ambiguous.

Lady fern, or wood fern?

dryopteris intermedia

I’m pretty sure this is intermediate wood fern (Dryopteris intermedia) and not lady fern (Athyrium felix-femina), but I’m not 100% certain.

Cullina lists ferns alphabetically by botanical name, so if I hadn’t seen the picture of the lady fern first, perhaps I never would have considered it. At first glance it looks exactly like the fern growing in my woods, and it’s supposed to be the most prevalent fern in my area, so there you go–except nowhere could I find a mention of it being evergreen during the winter.

So I searched online for evergreen ferns, and the name Dryopteris kept coming up. It turns out Dryopteris intermedia (aka intermediate wood fern, fancy fern, and glandular wood fern) also looks exactly like my fern. So, which is it?

possible scales on stipe

Both ferns are supposed to have scales on the stipe.

I took one sample frond to bring into the house, but it occurs to me that fern fronds that have been through a couple of months of winter are bound to be a little beat up. The brown, papery stuff stuck to the lower stem doesn’t much look like a scale to me, but maybe if I saw a newly unfurled frond in spring it would look more like it. Also, the wood fern is supposed to have “short glandular hairs, visible with a good hand lens.” I think we have a magnifying glass somewhere in the house, but I couldn’t find it.
wood fern frond

The easiest way to distinguish these two ferns? The sori (spore cases) are circular on the intermediate wood fern.

What do you think? The lady fern’s sori are supposed to look like eyebrows.
sori detail

Not a very sharp photo when blown up, but I think the sori are circular.

dryopteris intermedia in snow

Intermediate fern today.

moss and two kinds of ferns

Here they are during February of last year. They do get flattened by snow, but they are green.

A thaw–however brief–in winter gives me a taste of the coming spring, and seeing these evergreen ferns only strengthens the feeling that the plant world is poised to spring into growth as soon as the signal is given.

Posted for Wildflower Wednesday, created by Gail of Clay and Limestone, to share wildflowers/native plants no matter where you garden in the blogosphere. “It doesn’t matter if we sometimes show the same plants. How they grow and thrive in your garden is what matters most. It’s always the fourth Wednesday of the month!”

About the Author

Kathy Purdy is a colchicum evangelist, converting unsuspecting gardeners into colchicophiles. She would be delighted to speak to your group about colchicums or other gardening topics. Kathy’s been writing since 4th grade, gardening since high school, and blogging since 2002.

In the end, this may be the most important thing about frost: Frost slows us down. In spring, it tempers our eagerness. In fall, it brings closure and rest. In our gotta-go world–where every nanosecond seems to count–slowness can be a great gift. So rather than see Jack Frost as an adversary, you could choose to greet him as a friend.

~Philip Harnden in A Gardener’s Guide to Frost: Outwit the Weather and Extend the Spring and Fall Seasons

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Perfect Plants February 2, 2018, 1:37 pm

Interesting information here. We don’t have much snow down here in North Florida. But we do have ferns and boy do we love them πŸ™‚ my current obsession is with staghorn ferns and how they love the humidity… I keep mine in the shower. It’s especially nice since I do not have a vent fan in the bathroom so it is nice and humid and wet in there for my ferns (and orchids). PLANTS ARE AWESOME!

Doug January 26, 2018, 10:00 am

Many of our native ferns are easy to identify once one learns what to look for. It’s worth the effort and any good fern book can help. What you’ve got is Dryopteris intermedia, identifiable by the sori and the lower pinnae on each frond. Many ferns are also fairly easy to grow from spores by following the instructions in Cullina’s excellent book.

Kathy Purdy January 26, 2018, 11:06 am

I had read about the lower pinnae but they seemed to be missing on the sample I took. What is your favorite fern book?

Doug January 26, 2018, 12:30 pm

As an admitted pteridomaniac, I have a shelf-full of fern books. Still, compared to many other plant groups, ferns have been relatively neglected. In addition to Cullina’s book, my go-to books for cultivating ferns are “The Encyclopedia of Garden Ferns’ by Sue Olsen; “Ferns” by Olsen and Richie Steffen; “Ferns For American Gardens” by John Mickel; and “Fern Growers Manual” by Hoshizaki and Moran. For identification I think it is best to rely on regional guides. I like “Midwest Ferns” by Steve Chadde; and “Ferns & Allies of the North Woods” by Joe Walewski. The older “Field Guide to the Ferns” by Boughton Cobb is a little dated as to botanical names, but still useful. I hope this helps.

Kathy Purdy January 26, 2018, 4:21 pm

Thank you. I want to start learning more about ferns.

Linda from Each Little World January 25, 2018, 3:28 pm

Christmas fern, Autumn fern and Himalayan maidenhair fern all look fairly good when the snow melts in my garden. I think those sori are circular but I have trouble identifying ferns even with three books on the subject. Now I try to be more careful about making notes about what I planted where.

Pat Leuchtman January 25, 2018, 1:38 pm

I do not have any knowledge of ferns either, but in my new town garden I have northern maidenhair fern, and lady fern. At least that is what the labels said when I bought them. Both are hidden under the snow right now, but one of my resolutions is to be more accurate in my plant namings. I thought this was a really great post. Thank you.

Lea @ Lea's Menagerie January 25, 2018, 10:12 am

Pretty photos and interesting information! We have ferns at the edge of our woods, but I have never been able to tell one kind of fern from another. But I appreciate their beauty!

Lisa at Greenbow January 25, 2018, 5:55 am

I love ferns. I used to have Christmas fern but it got bullied out of a bed I guess because it disappeared. It had even reproduced. I was sad to lose it. I have also had Lady Fern. I actually think it is still out there. I will have to go out and see if it is green.