Var. _minus_, smaller; fronds often in pairs. The sterile segment
yellowish-green, attached usually much below the middle of the plant. Sandy
ground, New Hampshire to New Jersey.

Var. _Engelmánni_. (Given specific rank in Gray.) Has the sterile segment
thicker and cuspidate, the stipe slender and the secondary veins forming
a fine network within the meshes of the principal ones. Virginia and
westward.

Var. _arenàrium_. (From the Latin, _arèna_, meaning sand, being found in
a sandy soil.) Probably a depauperate form of _Ophióglossum vulgàtum_ and
about half as large. A colony of these ferns was discovered growing in poor
soil at Holly Beach, New Jersey.




KEY TO THE GRAPE FERNS

(_Botrýchium_)

Plant large, fruiting in June, sterile part much divided:
Rattlesnake Fern.
Plant smaller:
Fruiting in autumn, sterile part long-stalked, triangular.
Common Grape Fern.
Fruiting in summer:
Plant fleshy, sterile part mostly with lunate segments.
Moonwort.
Plant less fleshy, segments not lunate: