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Southern Adder's Tongue Fern (Ophioglossum vulgatum) and
Rattlesnake Fern (Botrychium virginianum)

Two ferns belonging to the plant family Ophioglossaceae can be seen along some of the Arboretum trails in late April and early May. This group of ferns is considered to have primitive characteristics and is not closely allied to other living ferns. Plants in this family have two-parted leaves, a basal sterile portion that can be simple or compound and an upper fertile portion bearing sporangia.

Southern Adder's Tongue Fern The Southern Adder's Tongue Fern is an unusual fern with a simple, ovate leaf subtending an erect, fertile stalk which bears the sporangia. This fern is widely distributed in the U.S. (many eastern states, Texas and Oklahoma), but is also found in Mexico and Europe. It is often difficult to find and frequently occurs in disturbed areas such as the edges of fields and forested roadsides.

Rattlesnake Fern The leaves of Rattlesnake Fern consist of a basal three-parted compound leaf subtending a fertile spike bearing sporangia. The fertile portion resembles the rattles of a rattlesnake. This fern is found throughout the U.S. and Canada. where it typically occurs in rich, moist forests.

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University of Tennessee - Forest Resources AgResearch and Education Center
901 South Illinois Avenue, Oak Ridge, Tennessee 37830 · Telephone: 865-483-3571 · Email: UTforest@utk.edu