I’ve shown images of my bird’s nest fern (asplenium nidus) leaves before in late January when I was talking about house plant pests. Back then, I was talking about scale, those nasty little raised brown or opaque tan pests that suck the juices from plant leaves (and cause the plant to secrete sap, possibly leading to other issues as well.)
In fact, if you look closely, you’ll see one little hard brown knob of scale on this leaf as well. It is on the lower mid-rib, near the bottom of those “brown stripes”–about 5 “brown stripes” up from the bottom. Further up, there is also an immature pale scale, but I am not even going to go there.
What are all those “brown stripes?” Well, actually, that’s what this post is about. I’ve already talked about the scale and you can find that post here if you want it.
Those brown stripes are actually spores–the way the fern reproduces.. If you remember a little bit about fern biology, you remember that ferns reproduce by “spores” and not seeds.
In fact, at certain times of the year, if you receive a bouquet with fern fronds, there will usually be little brown dots along the back. Those are the fern’s reproductive spores.
It’s far more unusual for a fern to have spores like those pictures above.
Then, of course, there is the “Sensitive” fern, (onoclea sensibilis) a native perennial. It sends up an entirely different structure of reproductive spore cases. You can read more about that here if you so choose.
So if you see something like this on the back of your bird’s nest fern leaves (the spores, not the scale) don’t be alarmed and don’t try to remove it. It’s just a perfectly natural part of the plant’s life cycle.
If fact, if you like, you can even try to propagate them–although I understand that it is terribly difficult unless you have the right conditions. My very cold house doesn’t qualify so I don’t even try.