Dec 10, 2011


Moonworts are tiny plants that were first discovered and documented centuries ago. However, the majority of modern humanity doesn't even know they exist!
Moonworts (Botrychium spp.) are ancient plants that are distant relatives to ferns. They tend to be so small in size that anyone who has walked through native prairie or woodlands in the spring or summer has likely stepped on a few and was totally unaware. Moonworts are known to occur in various habitats worldwide.
The common name moonwort reflects the medieval belief that the plant has mystical powers. Folk lore indicates that it was believed the power of moonworts was strong enough to pull the shoes off of wandering horses, and if a person was dusted with the spores they would become invisible.
Taxonomists first started describing the genus Botrychium, and a few of its member species, as early as the mid 1500s. Description and classification work has continued through the centuries since then, but a more concentrated effort was launched about two decades ago.

The evolution, taxonomy, and life cycle of the genus Botrychium is so complex that even after two decades of extensive research taxonomists and researchers are still largely confounded as to what makes the plants tick. The purpose of this article is to not to get into that, but rather to introduce the general populace to a unique plant in our midst.
Biology of Botrychium for Beginners
Most of a moonwort plant is underground. The only above ground expression that indicates a moonwort is present is a single branched stalk. The branching occurs at ground level or slightly above splitting into a sterile leaf-like frond called a tropophore, and a fertile spore producing appendage called a sporophore.
When the immature plants emerge from the ground, the tropophore is clasped tightly around the sporophore making the two parts look like one. The size of the emergent Botrychium is often only the size of a pin head or slightly larger. As they mature, some of the plants increase in size to over an inch tall, but others remain minute. As the plant matures the tropophore unfurls itself from being wrapped around the sporophore and the two distinct plant parts become visible. The amount of time it takes for the plants to emerge and mature depends on weather and moisture availability, but generally is anywhere from two to four weeks. Then they dry up and disappear underground for the rest of the year.
Telling one species of Botrychium from another can be a challenge even for the experts. There are a number of characteristics of the tropophore and sporophore that can be fairly reliable for identification, but there often tends to be overlap of those characteristics between species. The small stature of the plants sometimes make the characteristics impossible to see.
Hybridization between species also makes identification of moonworts difficult because the hybrids carry traits of both parent plants. Some moonworts are considered "masters of disguise" and stump even the experts. In those cases, the only way to tell for sure the species is by collecting the above ground portion of the plant and having it genetically analyzed. Collecting the above ground part of a moonwort does not affect the viability of the underground parts.
The underground life of the genus Botrychium is where understanding of life cycle gets murky. It has been determined that that the tropophore doesn’t photosynthesize, but instead the plants get nutrition through a symbiotic relationship with other plants and mycorrhizal fungi. At least part of the reproductive capability of moonworts is thought to occur underground, but without the ability to repeatedly observe what happens beneath the soil, scientists struggle to explain exactly what goes on.

Where Can You Find Moonworts?

Finding moonworts involves locating suitable habitat, taking a close look by crawling around and parting taller vegetation, and much of the time luck!
In the Midwestern United States, suitable habitat is determined by what other plants are growing on a site. Moonworts can often be found in native dominated prairie containing big bluestem, little bluestem, strawberry, and snowberry.
Moonworts seem to tolerate light to moderate disturbances. They have been found in areas shortly after prescribed burns. However, it should be noted that they may have been there before the fire, yet not visible because they were hiding in tall grass or deep litter. They also have been found in more severe disturbances that are much older, such as on abandoned roads, road cuts or logging skid trails. In those cases, the disturbance is generally at least 20 years old and most of the vegetation has grown back.
Suitable habitat for Botrychium pumicola (also known as pumice grape fern) is only found in the Cascades of south central Oregon and near Mt. Shasta in California. The Oregon plants favor frost pockets in the relatively young soils deposited during the eruption of Mt. Mazama.
Each year small armies of people get struck by moonwort madness, and they head for the prairies and woodlands to get a fix. If you see bunches of people out in the wild lands acting strangely and crawling around on their hands and knees, ask them what they are doing. They’ll probably tell you they’re looking for moonworts!
D. Farrar, Systematics of Moonworts Botrychium Subgenus Botrychium. Accessed December 3, 2011.
W. H. Wagner & D. Farrar, Botrychium campestre (Iowa moonwort) . Accessed December 6, 2011.
Author conversations with Dr. Don Farrar, Botrychium Expert, Iowa State University

Read more at Suite101: Those Magical Mystical Moonworts |