The Curious Case of the Antenna Fern
I’ve been keeping houseplants for over fifteen years, and fairly early in that timespan I became a serious hobbyist. At this point, it’s not that common for me to find a species of plant for sale in a nursery I’ve never seen before. I wish it happened more often! However, recently I bought a fern that was completely new to me.
Some context: I keep what I would consider to be a small number of ferns; many ferns require a level of watering or humidity that can be hard for me to consistently supply. I was previously holding stable at four species of ferns which have proven pretty resilient - Nephrolepis exaltata 'Mini Russells' (a miniature Boston fern cultivar), Nephrolepis exaltata ‘Green Fantasy’ (another miniature Boston fern cultivar), Polypodium formosanum 'Cristatum' (ET Fern), and Davallia fejeensis (Rabbit's Foot Fern). However, due to my branching out into carnivorous plants, I’ve become more accustomed to daily watering. As such, I am willing to give more fern species a go and brought three new ferns into my collection this summer. Two of them I’ve either seen before even if I haven’t acquired them or at the very least have seen similar versions, and then there’s this third…
The tag called it the “Antenna Fern” and provided the scientific name Doryopteris cordata. When I purchased it, it had a soft groundcover of rounded, verdant, gently hairy leaves and I found it very attractive.
A few weeks after it had come into my collection, it appeared to be growing a very errant new leaf. Instead of unfurling at ground level, it grew taller and taller until it loomed eight inches over the rest and after unfurling, it looked to be a completely different fern. I assumed a spore or very small plantlet from another fern species had gotten mixed up in my plant, and figured that was that.
As a couple more weeks passed, I grew even more curious as I assumed that if it was a second fern, another leaf or two would begin to appear in a central crown formation. This hadn’t yet happened.
As I was studying my main plant while trying to see how the interloper was doing, I decided I wanted to know more about the “Antenna Fern.”
Upon researching the fern, the provided scientific name of Doryopteris cordata does not actually exist. This is not that surprising; plant nurseries often mislabel their stock. The actual scientific name is Doryopteris pilosa var. gemmifera. But here’s the real shocker: I discovered in my research that the second fern is in fact the first fern; Doryopteris pilosa var. gemmifera is an extremely dimorphic fern, but apparently as many as one in five fern species exhibit some degree of leaf dimorphism (this also surprised me). In this case, the dimorphism results in a sterile groundcover and a fertile canopy that is better able to disperse spores into the wind. The colloquial name “Antenna Fern” is in fact a nod to the fertile fronds.
My research also confirmed that this is a rare plant in both cultivation and in the wild; however, if you’re interested in it there do appear to be some online vendors offering it up! Just a note of caution, though - from my own experience, this fern does need moisture at all times; I went on a three-day trip and upon my return it was desiccated and crisping, whilst all my other ferns were doing just fine. A good drink did refresh it, however, and aside from a couple crisp spots it’s fully bounced back as you can see in the photo above! I do wonder if this is my fern’s first ever antenna, or if the nursery also thought that the fertile fronds were hitchhikers and cut them off…