Botrychium simplex is a type of fern, a pteridophyte, known variously as least moonwort, little grapefern, little grape fern and least grapefern. The botrychium species are known as moonworts. These seedless vascular plants in the family Ophioglossaceae are small, growing 2¾ inches to 5½ inches tall, with fleshy roots. They reproduce by spores shed into the air. One part of the leaf, the trophophore, is sterile and fernlike; the other, the sporophore, is fertile and carries the clusters of sporangia or spore cases. The spore-bearing fronds are dramatically different from the sterile fronds.
The fronds of least moonwort are less dissected and lobed than in other species, hence the specific epithet of simplex. However, this species is, in other respects, highly variable.
The sterile frond is a single leaf, pale green in color, smooth and fleshy, about 1½ inches long, simply compound, and close to stem; often clasping. The sterile frond’s position on the leaf stalk is variable.
The fertile frond rises above the leaf as a single, unbranched stalk with prominent spore cases.
The stem is pale green, slender, succulent, and fragile; about ¾ of an inch long.
The rootstalk is small and upright. Roots tend to be few; smooth, fleshy, and spreading; they descend to about 2 inches below the surface.
There are no scales on the leaf stalk and there are no hairs on the leaf stalk. The veins go all the way to the edge of the leaf blade.
Individuals tend to be inconspicuous and scattered. One way of identifying these plants is by there diminutive size, succulent stem, and single compound leaf, as noted most often clasping, combined with its unbranched fertile frond.
The least moonwort is spotted in dry fields, marshes, bogs, swamps and roadside ditches.
This fern is present in high elevations from Southern California to North Carolina and northward to Alaska and Newfoundland; it is also widespread in the Old World, but in many places it is considered endangered because of extreme rarity. In Europe, particularly, botrychium simplex and other vascular plants are threatened with extinction and declining, as a result of urbanization and expanding infrastructure. The presence of ferns are considered by scientists to be an indicator of healthy ecosystems.
From Wikipedia, GoBotany website and http://www.rook.org