Note:  Do not rely on this information. It is very old.

Moonwort

Moonwort (Botrychium Lunaria), a somewhat uncommon British plant, forming with the adder'stongue (Ophioglossum vulgatum) our only representatives of the Ophioglossacea3, a group closely related to the ferns. The prothallus is subterranean, colourless, and monoecious, as in club-mosses; the stem short, erect, and unbranched, and there is generally only one leaf. This takes five years to develop, has a long stalk, is leathery and smooth, and divides at an early period into two branches. One of these is green and barren, and gives itsname to the plant by dividing pinnately into half-moonshaped segments; the other is also pinnate, but has no green cellular tissue, consisting entirely of globular sporanges, each formed from a group of cells (eusporangiate) taking a year to develop and bursting in two halves.