Nephrolepis exaltata

Taxobox
name = Boston fern

The Sword Fern ("Nephrolepis exaltata") is a species of fern in the family Lomariopsidaceae (sometimes treated in the families Davalliaceae or Oleandraceae, or in its own family, Nephrolepidaceae), native to tropical regions throughout the world. It is common in humid forests and swamps, especially in northern South America, Mexico, Central America, Florida, the West Indies, Polynesia and Africa. Also known as the Wild Boston fern, Tuber ladder fern or Fishbone fern is in the broader family of sword fern.

The fronds are 50-250 cm long and 6-15 cm broad, with alternate pinnae (the small "leaflets" on either side of the midrib), each pinna being 2-8 cm long. The pinnae are generally deltoid, as seen in the picture to the right. The pinnate vein pattern is also visible on these highly compound leaves. The edges appear slightly serrate. The species has erect fronds, but "Nephrolepis exaltata cv. Bostoniensis" (Boston Fern), the most commonly cultivated cultivar, has gracefully arching fronds. This mutation was discovered in a shipment of "N. exaltata" to Boston from Philadelphia in 1894. [ [http://www.aces.edu/pubs/docs/A/ANR-1095/ANR-1095.pdf?PHPSESSID=b5bbe727be409a0d380e892ed18e811f Greenhouse Production of Boston Ferns - Alabama Cooperative Extension System] ]

Cultivation and uses

The Boston fern is a very popular house plant, often grown in hanging baskets or similar conditions. It is a perennial plant hardy in USDA plant hardiness zones 9-11. Although the fern may appear totally dead due to frost, it will re-emerge in the spring. In general, the Boston fern likes damp, but not soggy soil that is rich in nutrients. Of the common cultivated ferns, the Boston fern is the most tolerant to drought. The fern thrives best in humid conditions, so when grown as a house plant it becomes necessary to mist the plant when relative humidity falls below around 80%. Although outdoors this plant prefers partial shade or full shade, inside it grows best in bright filtered light. This plant is usually propagated by division of the rooted runners, as named cultivars will not produce true spores.

Boston fern is native to Florida, the West Indies, and Asian Pacific. A related species, the Tuberous Sword fern ("Nephrolepis cordifolia"), is frequently confused with Boston fern and is a serious exotic invasive plant, forming dense monocultures.

References

* [http://www.ars-grin.gov/cgi-bin/npgs/html/taxon.pl?25202 Germplasm Resources Information Network: "Nephrolepis exaltata"]
* [http://www.floridata.com/ref/N/neph_exa.cfm Floridata: "Nephrolepis exaltata"]