The Ophioglossaceae

The Adder's Tongue Ferns

Botrychium minganense	Ophioglossum engelmannii

The Ophioglossaceae are a family with a nearly worldwide distribution. The family contains 9 genera and aproximately 70-120 species. The Ophioglossaceae are one of two extant eusporangiate fern families and apparently have no close affinities to other extant ferns. Recent molecular evidence (Pryer et al., 2001) demonstrates that Ophioglossaceae and Psilotaceae are sister groups and are themselves siter to all other extant fern families including Equisetaceae.

Click here for a distribution map of the Ophioglossaceae in the U.S.A.

Vegetative Characters | Reproductive Characters | Diagnostic Characters | Economic Importance/Fun Facts | Evolutionary Adaptations and Relationships | Glossary of Terms | References and Links | Pictures

Vegetative Characters

• each frond is divided into fertile and sterile segments
• usually a single frond is produced above ground per year
• sterile segment may be simple and entire, or highly dissected to compound
• roots with mycorrhizal associations
• fronds lack circinate vernation and stems lack sclerenchyma

Reproductive Characters

• the fertile segment bears many sporangia
• sporangia are eusporangiate in structure
• thousands of spores are produced per sporangium
• gametophytes are underground, non-photosynthetic, and mycorrhizal

Diagnostic Characters

• the main synapomorphy = division of the frond into fertile and sterile segments
• distinctive sympleisiomorphies = eusporangia, non-photosynthetic gametophytes

Economic Importance/Fun Facts

• they are the most facinating of all extant plants :)
• some species are epiphytic
• some species are called crptic because they can be difficult to distinguish
• Dr. Hauk did his Ph.D. research on them

Evolutionary Adaptations and Relationships

• Order Ophioglossales
• clearly monophyletic
• sister group to Psilotaceae
• within family relationships determined by rbcL, trnL-F, and morphological data (Hauk, Parks, and Chase, manuscript submitted).

Glossary of Terms

• extant - alive on Earth today (opposite of extinct)
• mycorrhizae - a symbiotic relationship between a plant root and a soil fungus
• eusporangium - a thick walled, large sporangium that produces thousands of spores
• gametophyte - the haploid stage in alternation of generations
• epiphyte - a plant that lives on another plant (not a parasite)
• circinate vernation - the coiling associated with young fern leaves
• sclerenchyma - tough, support tissues with evenly thickened secondary walls

References and Links

• Pryer, K. M., H. Schneider, A. R. Smith, R. Cranfill, P. G. Wolf, J. S. Hunt, and S. D. Sipes. 2001. Horsetails and ferns are a monophyletic group and the closest living relatives to seed plants. Nature 409: 618-622.
• Judd, W. S., C. S. Campbell, E. A. Kellogg, P. S. Stevens. 1999. Plant Systematics: a phylogenetic approach. Sinauer Associates, Inc. Sunderland, MA U.S.A.
• Wagner, W. H., and F. S. Wagner. 1993. Ophioglossaceae C. Agardh: Adder's-tongue family. Pp. 85-106 in Flora of North America North of Mexico Vol. 2: Pteridophytes and Gymnosperms, eds. Flora of North America Editorial Committee. Oxford University Press, New York, NY.

Pictures

Ophioderma pendula	Cheiroglossa palmata

spp.	spp.

For questions or feedback, contact: Warren Hauk