DRYOPTERIS (L.) Newman
Common Oak Fern
FAMILY: Aspleniaceae (Polypodiaceae)
SYNONYMS: Dryopteris disjuncta (Ledeb.) C.V. Morton Phegopteris
dryopteris (L.) Fee
HABIT: Perennial from a slender rhizome, fronds
deciduous, 0.4-5 dm.; sporulating June-September.
SIMILAR SPECIES: This delicate fern resembles depauperate
beech ferns (Phegopteris spp.), which also grow in similar habitats.
However, the fronds of oak fern are definitely ternate, while those of beech
ferns are pinnate.
TOTAL RANGE: Greenland to Ont., s. to NJ, VA, OH, MI, WI,
and MO; the typical variety occurs to the west and northwest of this range.
STATE RANGE: There are post-1960 collections from 5
counties: Columbiana, Erie, Jefferson, Lorain, and Mahoning. There are pre-1960
specimens from 5 other counties: Ashtabula, Lake, Licking, Portage, and Wayne.
STATE STATUS: 1980 to present: Threatened.
HABITAT: Mesic woods and slopes, often with hemlock.
HAZARDS: Drying of habitat by removal of forest canopy; soil
RECOVERY POTENTIAL: Probably poor.
INVENTORY GUIDELINES: Collect complete, mature specimens.
COMMENTS: This species may be overlooked because of its
delicate appearance or misidentified as other species. It does appear, however,
to be limited to northeastern Ohio, where suitable habitats are rarely
Like many other fern taxa, this plant has undergone radically different
treatments, having been placed in three separate genera (see Synonyms). The
treatment used here is one followed by most recent authors.
Oliver, J.C. 1972. Preliminary systematic studies of the oak
ferns: chromatography and electrophoresis. Amer. Fern Jour. 62: 16-20.
Wagner, W.H., Jr. 1966. New data on North American oak
ferns, Gymnocarpium. Rhodora 68: 121-138.
Division of Natural Areas and Preserves
Ohio Department of Natural Resources
Created: 3/1982 Allison W. Cusick
Database Code: SPEF.296