May 2009
Home Grown Tomatoes

Is that a Selaginella, Lycopodium or Diphasiastrum?

A couple of weeks ago, I was hiking in a hollow along Straight Mountain in Blount County identifying spring ephemeral wildflowers when I stumbled upon a plant I had never seen before in that region, or even in my plant references.

At first, I thought it was a bunch of little conifer seedlings popping up from the leaf and pine straw litter on the forest floor. After closer examination, I noticed the little plants were much too large to be seedlings of any kind. They looked like small green umbrella frames, three inches, or so, in diameter and spiking up about two to three inches from the ground. The texture seemed as that of an Arborvitae or Cypress. I had seen something like them before, but I could place neither what nor where.

Fan Clubmoss (Lycopodium digitatum)


After taking a couple of pictures of the specimen, I noticed they were all over the place in that area. I decided it probably wouldn’t hurt collecting a sample of the plant to bring back home for identification. As I attempted to collect one, I noticed they were interconnected by a single stem running from spike to spike, just below the leaf litter. Therefore, I collected one plant having 11 spikes.

I showed the plant to one friend who suggested it might be a Selaginella. Ah-hah! That’s where I had seen this type plant before! I used to raise a type of Selaginella called ‘Cypress Selaginella.’ My plant had a similar texture, growth habit and overall look of that plant, but not exactly. I sent an image to a couple of other friends who came up with the correct genus and species right away and responded back to me within five minutes of each other. Both Dr. Larry Davenport of Samford University and Tony Glover of the Alabama Cooperative Extension System suggested the plant was in fact a Lycopodium and not Selaginella.

However, after reading further about this plant, I discovered both plants are related in that they both, in the plant kingdom, belong to the Division, Lycopodiophyta! Wa-ay cool, huh? So what do it all mean and what is a Diphasiastrum?


The plants are all considered to be fern allies and the common names are clubmoss and spikemoss, though they are neither fern nor moss. These plants are some of the earliest plants found in prehistoric studies. Both Diphasiastrum and Lycopodium are argued to be one in the same in some botany circles.

The bottom line is these plants will all do well in a filtered sun, moist garden with slightly acidic soil. If you can grow an azalea there, try these plants as a groundcover underneath the azaleas. And if you can’t identify the plant from your own database, don’t be ashamed to ask somebody else.

E-mail me at This email address is being protected from spambots. You need JavaScript enabled to view it. if you need further information on Lycopodiaceae.

Friend me at and go to to listen live and access the new podcasts coming soon!

I hope you will all tune in each Saturday from 8 until 10 a.m. CDT for Home Grown Tomatoes. If you are not in the local coverage area, then tune in on the Internet by going to and follow the links to listen live!