It’s amazing how much time you can spend outdoors and still know so little about nature. Before I hiked the Pacific Crest Trail in 2014 I naively thought by the end I’d have a pretty good grasp of at least all the common plant species from spending 5 months outside. I came back only knowing about 10 new ones.
Getting to know nature isn’t hard but it takes intention. It’s also worthwhile, as the more you know the richer your outdoors experiences become. There’s something wrong when you’re camped in a forest and you can intimately describe every aspect of your gear but don’t know the species of trees you’re camped within.
Besides the value of understanding nature for interests sake, learning to be a naturalist also has some practical benefits for the outdoors person. When you know plants, you realize their presence and state tells you lot about the area you’re in, edible foods, the time of year, what animals should be there and when, how the season has been etc. To this, trees tell you about large scale differences in habitat. Mosses tell you fine scale differences with amazing resolution and ferns are the happy middle – at least in wet-ish areas like the Cascades and Coast mountains. They’re better for this than flowers and shrubs because ferns are easy to learn, abundant and quite habitat specific.
Like trees, learning ferns isn’t hard. If you take the time to learn 5 or so then you’ll know most of them and when you come across one that you don’t know, it’ll stand out Here I present a quick guide to the 5 most common fern species in the PNW plus 2 less common but awesome ferns. Know these and you’ll know 90% of the ferns you see.
Common Western Ferns
1) Deer Fern
2) Sword/Christmas Fern
3) Bracken Fern
4) Lady Fern
5) Oak Fern
Deer Fern (Blechnum spicant) is the most “basic” looking of the western ferns. Like Sword Fern, it has leaves that are divided just once aka “once pinnate”. The unique part is they are fully connected to the stem at the base instead of having mini stems. Licorice Fern is fully connected too (see Bonus section) but it only grows in single fronds, not clusters, and only on vertical surfaces like cliffs. Deer fern grows on the forest floor in medium sized clumps of bright green fronds that are knee to waist high. There’s nothing edible about it.
Sword/Christmas Ferns are two closely related species in the Polystichum genus. They are vaguely similar to deer fern in that they have simple “once pinnate” leaves but a key difference is the leaves are attached to the stem via short little stems and they have a funky lobes at the base. There’s nothing else like this and it’s probably the most common western fern. In the coast mountains you’ll find mostly Sword Fern (Polystichum munitum), while in the Rockies it’s mostly Christmas fern (Polystichum acrostichoides). These ferns are a deeper shade of green than Deer Fern and get big, with plants up to chest high. You can cook, peel and eat the roots in a pinch but I’m told they’re not tasty.
Bracken Fern (Pteridium aquilinum) has leaves that are divided 2-3 times instead of once, so it’s obviously different from the prior 2 ferns but sort of similar to the next. Notice how the “fronds” are roughly triangular shaped. If it’s big (e.g. waist high) and has triangular fronds then it’s Bracken fern. The only ferns you’re likely to mistake it for are Lady Fern (below), Oak Fern (tiny) and maybe small rare ferns. Oak Fern is way smaller (e.g. 6″), while Lady Fern has a very different shape. You can eat young fiddle heads if you boil them and then fry them, but some people think they’re not great for you. It’s controversial topic, but certainly in a survival situation you can cook up a batch.
Lady Fern (Athyrium filix-femina) is similar to Bracken in that it’s also 2-3x divided (“twice pinnate”) but the shape of the fronds is much different. They are widest in the middle and then taper to the base, whereas Braken is widest at the base. This shape is an easy way to ID them. It looks sort of similar to Ostrich Fern (found only out east) which is where most of the edible fiddleheads come from in grocery stores. Lady Fern also has edible fiddle heads and they are the main ones foraged out west. Peel the brown bits off, boil well then fry.
Oak Fern (Gymnocarpium dryopteris) is like a bracken fern in that it’s divided several times and forms a wedge shape, but it exists as a single, small frond instead of cluster of big fronds. This single frond always has 3 lobes as the photos show. Usually there’s a bunch of them in a patch. You’ll find these in the forest understory in darker places. Usually deciduous forests.
Bonus Cool Ferns
6) Licorice Fern
7) Maidenhair Fern
Licorice Fern won’t grow on the ground – it insists on a mossy vertical surface like the sides of mossy boulders and mossy deciduous trees like Big Leaf Maples. It’s also unique in that it only grows in single fronds (which are connected by a rhizome running through the moss) rather than in a cluster of fronds like most ferns. It’s a once pinnate fern like Deer and Sword Ferns with the color of Sword Fern and leaves fully attached like Deer Fern but it’s unmistakeable for the aforementioned reasons. The rhizomes that connect the fronds aren’t really edible but they do have a really strong sort of sweet taste that people like to nibble on. Just chew a tiny bit.
Maiden Hair Fern is my favourite. It will only grown in a really wet spots, like right next to a stream or at a seep. It’s unique with it’s black stems and uniquely shaped leaves. It’s not edible but it’s beautiful.
Ferns are mostly located based on moisture. Of these ferns, Maidenhair likes it really wet – often living on rocks along a stream. Lady Ferns also likes wet habitat but isn’t exclusively right at the water. You’ll find them in ravines and along streams. Deer ferns are the next wettest and you’ll often find them near but not next to water and on shaded, damp slopes and in the wet temperate forests like the Olympic Pennisula. Next are sword ferns, which like it a bit damp but not as wet. They’re common in cool forests. Oak Ferns like shady, semi-dry forest bottoms. Bracken Ferns are the most tolerant of hot and dry conditions, so you’ll find these in areas like south facing slopes and the rain shadow side of a mountain range.
Great post. Thanks.
Thank you so much for this! I too have been teaching myself wildflowers the past two Springs/ Summers and I will start delving into the ferns next. Your page has been invaluable to my journey.
This is a great overview! The last “licorice fern” might actually be a “leatherleaf fern” [https://www.inaturalist.org/taxa/64288-Polypodium-scouleri], another great “bonus” fern found on the coast.