Fern-like ground cover's ancient lineage traced to Africa | Mystery Plant

In 1947, Dr. Seuss (Theodore Geisel) published a children's book titled “McElligot’s Pool.” If you didn’t read this as a child, you can as an adult, and I recommend it.

The story involves a little boy fishing in a small pond, who begins to imagine the amazing fish that he might hook, if he just gives it a try. To me, this is a story about our fascination with discovery, whether in far-off distant places or perhaps a bit closer to home. So, here’s a little example of discovery of the latter sort.

This past spring (it was late April), I was put in contact with Carol Kleppin, a nice lady living in Summerville, S.C., not so far from Charleston. It turns out that Carol had discovered a very strange plant in her backyard. She described it to me as a low ground cover of unknown origin, spreading rapidly, and perhaps it would soon be covering her lawn. Or worse. Time for a botany road trip.

Off to Summerville I went, intent on making an herbarium specimen or two of Carol’s plant, and getting a good identification for it. Sure enough, this low, little thing — matted spikemoss (Selaginella kraussiana) — was advancing rapidly in her yard, only a few inches high, and was forming a rather substantial ground cover all by itself.

It turns out that matted spikemoss is related to various kinds of fern-like plants called “clubmosses.” These are from a very ancient lineage, and like ferns, reproduce from spores.

Carol’s plants were soft to the touch, forming branched mats close to the ground. Tiny egg-shaped leaves are found in rows — on the sides of the stem, and even tinier ones in rows on the top of the stem.

The stem tips branch repeatedly, and at the tips, form flattened branches. Sometimes the plants form mounds, and stick up into the air, off the ground. When the time is right, they will produce very small cone-like structures from which the developing spores will be shed, capable of starting new plants.

This little ground cover (which is quite pretty, I think, with its shiny, somewhat iridescent foliage and stems) is native to southern Africa, and has in fact been offered in the trade here in the United States.

As you might expect, a plant that reproduces by spores and is easily grown in pots or terrariums is likely to spread, if it gets the chance … and that seems to be what is going on in this backyard.

Carol’s close-to-home discovery is indeed evidence that this species is happy to be weedy in the Southeast. So far, matted spikemoss has only been found outside cultivation in a very few places in Alabama, Georgia and the Carolinas. But it looks as though it might yet spread further.

If you happen to discover plants in your backyard (or wherever) that seem out of place, or otherwise odd, consider reporting them to a botanist at your local herbarium. Botanists tend to be very pleasant, inquisitive creatures, and they might want to come out and take a look.

John Nelson is the retired curator of the A.C. Moore Herbarium at the University of South Carolina in Columbia, S.C. As a public service, the Herbarium offers free plant identifications. For more information, visit www.herbarium.org or email johnbnelson@sc.rr.com.