Botrychium multifidum (S. G. Gmelin) Ruprecht
leather-leaved grape-fern
Family: Ophioglossaceae
sterile plant
fertile plant

There are four species in this group of Botrychium species with broadly triangular blades over 10 cm wide (often at least 15 cm) and with the fertile branch diverging far below the base of the sterile blade: B. multifidum, B. rugulosum, B. oneidense and B. dissectum var. obliquum (var. dissectum is more distinctive and does not usually pose a problem). All four species bear their blades more or less horizontal and close to the ground and the point at which the fertile branch diverges is often so low that it might appear to the casual observer that the fertile and sterile branches arise separately. There is usually just one blade per plant and the blade often persists over winter. When the fertile branch is not present these plants may easily be overlooked in spite of their substantial size. Identification of these species may be difficult, even for experienced botanists.

The criteria for distinguishing these species can be found at steps 14-16 in the associated key. Botrychium oneidense, like B. dissectum var. obliquum tends to have the terminal portion of the pinnules less deeply divided than in B. multifidum and B. rugulosum. Botrychium dissectum var. obliquum has more acute blade segments than B. oneidense. The reader is directed to the Flora of North America, Vol. 2 for a more extensive description.

There are a few characteristics that can aid in the admittedly difficult task of separating these species. Botrychium dissectum blades often turn a bronze or brownish color late in the growing season and they may also occur together with B. dissectum var. dissectum, thereby providing a clue as to the identity. The blade of Botrychium multifidum tends to run a little larger than the other three species (though there is considerable overlap in size) and may be the most common of the four species. It can be numerous on some sunny sites, such as old pastures, forest clearings and forest edges. B. oneidense tends to be more associated with full or at least nearly full canopy and moist, rich deciduous forests. If B. multifidum is found under thoroughly canopied forests it is often sterile. B. rugulosum appears to be quite rare in Wisconsin and perhaps throughout its range. The habitat is unspecific, including "open fields and secondary forests" as described in the Flora of North America.

B. multifidum apparently does best in forest clearings, old fields and other sunny, grassy sites. It is also found in deciduous forests, although it is often sterile there. It has been reported across Canada, south to Pennsylvania, Minnesota and North Dakota, and extending south to Utah and California in the west. It is found throughout Wisconsin, but is apparently more common in the north.