The
Sword Fern (
Nephrolepis exaltata) is a species of
fernA fern is any one of a group of about 20,000 species of plants classified in the phylum or division Pteridophyta, also known as Filicophyta. The group is also referred to as Polypodiophyta, or Polypodiopsida when treated as a subdivision of tracheophyta...
in the family
LomariopsidaceaeThe Lomariopsidaceae is a family of ferns with a largely tropical distribution. It includes the following genera:*Bolbitis*Elaphoglossum*Lomagramma*Lomariopsis*Teratophyllum*ThysanosoriaSome are cultivated as ornamental plants....
(sometimes treated in the families
DavalliaceaeDavalliaceae is a family of polypod ferns, which includes seven genera, the species of which grow mostly in the old world tropics or subtropics. In some treatments the genera of the family Olandraceae are included in this family...
or Oleandraceae, or in its own family, Nephrolepidaceae), native to tropical regions throughout the world. It is common in humid
forestA forest is an area with a high density of trees. There are many definitions of a forest, based on the various criteria. These plant communities presently cover approximately 9.4% of the Earth's surface in many different regions and function as habitats for organisms, hydrologic flow modulators,...
s and
swampA swamp is a wetland featuring temporary or permanent inundation of large areas of land by shallow bodies of water. A swamp generally has a substantial number of hammocks, or dry-land protrusions, covered by aquatic vegetation, or vegetation that tolerates periodical inundation. The two main types...
s, especially in northern
South AmericaSouth America is the southern continent of the Americas, situated entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere...
,
MexicoThe United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...
,
Central AmericaManagua
Guatemala City
San Salvador
San Pedro Sula
Panama City
San José, Costa Rica
Santa Ana, El Salvador
León
San Miguel|-|}...
,
FloridaFlorida is a state located in the southeastern region of the United States, bordering Alabama to the northwest and Georgia to the north. It was the 27th state admitted to the United States...
, the West Indies,
PolynesiaPolynesia is a subregion of Oceania, comprising a large grouping of over 1,000 islands scattered over the central and southern Pacific Ocean.-Definition:...
and
AfricaAfrica is the world's second-largest and second most-populous continent, after Asia. At about 30.2 million km² including adjacent islands, it covers 6% of the Earth's total surface area and 20.4% of the total land area. With a billion people in 61 territories, it accounts for about 14.8% of the...
. Also known as the Wild Boston fern, Tuber ladder fern or Fishbone fern is in the broader family of sword fern.
The
frondThe term frond is used to refer to a large, divided leaf.In both common usage and botanical nomenclature, the leaves of ferns are referred to as fronds and some botanists restrict the term to this group...
s are 50-250 cm long and 6-15 cm broad, with alternate
pinnaThe pinna is the visible part of the ear that resides outside of the head .-Purpose:...
e (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.
Cultivation and uses
The Boston fern is a very popular house plant, often grown in hanging baskets or similar conditions. It is a
perennial plantA perennial plant or perennial is a plant that lives for more than two years. When used by gardeners or horticulturalists, this term applies specifically to perennial herbaceous plants...
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
soilSoil is a natural body consisting of layers of mineral constituents of variable thicknesses, which differ from the parent materials in their morphological, physical, chemical, and mineralogical characteristics. It is composed of particles of broken rock that have been altered by chemical and...
that is rich in nutrients. Of the common cultivated ferns, the Boston fern is the most tolerant to
droughtA drought is an extended period of months or years when a region notes a deficiency in its water supply. Generally, this occurs when a region receives consistently below average precipitation. It can have a substantial impact on the ecosystem and agriculture of the affected region...
. 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
cultivarA cultivar is a cultivated plant that has been selected and given a unique name because of desired characteristics; it is usually distinct from similar plants and when propagated it retains those characteristics....
s will not produce true
sporeIn biology, a spore is a reproductive structure that is adapted for dispersal and surviving for extended periods of time in unfavorable conditions...
s.
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.