Identifying ferns.. broadly

Can anyone share resources that allow you to give a rough (maybe to the family level) identification to different types of ferns?

All the guides I have found so far are geographically specific, I’d like to read something that works globally.

my guess is a global approach to identifying ferns would be very, very difficult.


i’ve not come across a key that covers ferns globally, but there are lists of all extant fern families with short descriptions of each.


That’s…a pretty big thing to ask, e.g., I don’t believe there are any synapomorphies for Dryopteridaceae, as currently circumscribed by phylogenetics. Some of the familial delimitations (esp. Woodsiaceae) have changed since Smith et al. 2006, the pioneering fern molecular phylogeny, but it is pretty good for describing useful characters of families, at least such as exist.

One that I often find useful, not mentioned there, is the pink color in young fronds of Blechnaceae. This also occurs in Onocleaceae, but those are largely extratropical, and in Adiantum, which is readily identifiable based on the subdivided leaves with dark axes, etc. Dichotomizing blades in Gleicheniaceae, tree ferns in Cyatheales, viny habit in Lygodium are also easily-spotted characters.


first @langzi this is a great request, ferns are another “hard” taxa and we too have been struggling to make a breakthrough so thanks for asking

while agreeing that it is a bit difficult to have non grographic specific guides I think the 3rd link posted by @pisum is fantabulous.

I have been working on a “tree of life” kind of thingy (not sure what to call it so for now it is a thingy) - will share the output once it is in a shareable state :-) so the 3rd link is a great idea.

The other two links are also great, I like the smith et al paper as well.


I glanced at the title of this thread and I thought the last word read “badly”. :rofl: That’s why I only identify most of mine to Class.

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Thank you very much everyone for your answers.
Now I understand why I could not find a global resource to simply sort fern families: because it is not simple!

I have taken note of the characters mentioned by Chloess and now have to go through the links provided by pisum…

I ID unknowns as ‘fern’ and in a few days, those who can, take them to species.
I follow the notifications and slowly slowly, learn to split them further.

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