The Botrychium genus is a complex group of plants known to science since the 16th century but only studied in depth since the last half of the 20th century.  In 1938 Clausen recorded just eight species of Botrychium in the United States; as of 2010 Farrar indicates we have over thirty species. This increase was in large part due to the work, from the 1950s through the end of the 20th century, of Warren and Florence Wagner, the authors of the Botrychium key for the Flora of North America.

The Botrychium life-cycle is fascinating yet still only partially understood.  Botrychiums have only one above-ground portion: one leaf which uniquely is split into two portions, a reproductive branch (the sporophore) and a photosynthetic branch (the trophophore).  Minute spores (produced in grape-like clusters on the sporophore) fall to the ground and are worked into the soil by rain, frost heave, and other natural forces.  The pin-head sized spores spend many years (5-10?) underground, they develop slowly, and eventually they produce a new plant which emerges above ground. Buds for several years of growth can be found in the below ground portion of the plant and it is thought that individual plants live above ground for 5-10 years.

Of crucial importance in the life cycle of Botrychiums is their association with mycorrhizal fungi.  The fungi are apparently attracted to the below ground spores by secretions of these spores.  The fungi attach themselves to the spores and provide the nourishment which the spores need to develop over many years. 

Botrychiums are most often found in disturbed areas, such as, avalanche chutes, rock slide areas, grazed meadows, and in man-made disturbances, such as, road-sides, ski-areas, and logging roads  --  all of the latter mimic the natural disturbed conditions that Botrychiums favor.  Botrychiums can be found growing in man-made disturbances about 15-20 years after the initial disturbance. 

Botrychiums in the Four Corners states seem to be most abundant above 9,000 feet. They are typically in well-drained soils rich in soluble minerals.  They are frequently found where four or five of the following are present: Androsace, Antennaria, Fragaria, Solidago simplex, Senecio atratus, Taraxacum officinale, mosses, lichens, and small Conifers.  They are not found with Vaccinium species or under a closed canopy. 

In sum, Botrychium are found in rocky/gravelly soils in the open spaces between what most of us look at: the flowering vascular plants.  One must retrain one's brain to avoid looking at flowers three, twelve, or twenty inches above the ground and instead to focus on the barren gravel and soil between the flowers.

Botrychium species are highly variable and identifying them to the species level is often quite difficult.  One must deal with mature plants.  According to Farrar and Popovich, "The most important characters for identification are the shape and cutting (dissection) of the pinnae [the individual leaf sections] as well as the lengths of the stalks of the trophophore and sporophore".  It is not necessary to examine the below ground parts of Botrychiums to identify them and, in fact, disturbing these parts should be avoided.  The Wagners indicate that "For accurate identification, a substantial number [of plants must be examined] because of the large amount of variation found in most species".

The Botrychiums of Colorado are the most studied and cataloged plants in the Four Corners states thanks to the work of Steve Popovich and Scotty Smith. (See the key developed by Farrar and Popovich and see Scotty's photographs of almost all of Colorado's Botrychiums).

The Botrychium genus was named by Olof Swartz in 1800; he replaced the original genus name of Osmunda given by Linnaeus in 1753.  The name “Botrychium” is derived from the Greek word “botrypus”, meaning “a cluster of grapes” and this refers to the cluster of spore-producing sporangia on the sporophore.

The plant is commonly known as "Moonwort", a name that, according to the Oxford English Dictionary, dates back to 1578 in Lyte's book, Dodoeus, a translation of a herbal by Rembert Dodoeus: 

"This herbe is now called in Latine "Lunaria", and "Lunaria minor".  In English "Lunarie" or 'Moonwort' ". 

Leaflets of some Botrychium are crescent-shaped, i.e., lunar-shaped, thus the Latin "Lunarie" and the English "Moonwort".  "Wort" (Middle English) is derived from "wyrt" (Old English) for "a plant".

For more information about Botrychiums:

Click for the excellent new illustrated Botrychium key developed by Don Farrar and Steve Popovich.  This is a draft of the Botrychium key and will be updated soon.

For photographs, drawings, and complete descriptions of almost all United States Botrychium, see Dr. Donald Farrar's web page on the Ada Hayden Herbarium web site.

Click for Donald Farrar's "SYSTEMATICS OF MOONWORTS BOTRYCHIUM SUBGENUS BOTRYCHIUM". 

Click for the Flora of North America key to Botrychium which is another tool to use in identifying Botrychiums but it is superceded by the Farrar and Popovich key.

See also Cindy Johnson's web page and articles: Moonwort Research and  "Phenology and Demography of Two Species of Botrychium".