Nephrolepis exaltata

leaf Main Plant Information

Genus

Nephrolepis

Species

exaltata

Hawaiian Names with Diacritics

  • Kupukupu
  • Niʻaniʻau
  • Palapalai
  • Pāmoho
  • ʻŌkupukupu

Hawaiian Names

  • Kupukupu
  • Nianiau
  • Okupukupu
  • Palapalai
  • Pamoho

Common Names

  • Common sword fern
  • Sword fern
  • True ʻōkupukupu

Names with Unknown Sources

  • Hawaiian Boston fern

leaf Plant Characteristics

Distribution Status

Indigenous

Endangered Species Status

No Status

Plant Form / Growth Habit

  • Non-Woody, Clumping
  • Non-Woody, Spreading

Mature Size, Height (in feet)

  • Fern/Fern-like, Tall, Greater than 3

Mature Size, Width

ʻŌkupukupu or niʻaniʻau can have a spread of 6 feet or more and grow to about 4 feet tall.

Life Span

Long lived (Greater than 5 years)

Landscape Uses

  • Accent
  • Container
  • Ground Cover
  • Hanging Basket
  • Indoor
  • Specimen Plant

Additional Landscape Use Information

A beautiful full spreading fern with fronds over three feet long makes ʻōkupukupu an ideal fern for deep pots, pots on pedestals, or hanging baskets in part shade to shady areas. Once established in the pots and hanging baskets they will send out rhizomes. When the small ferns begin to show a few fronds, they can easily be removed with some of the surrounding soil to make new plants without upsetting the entire pot. Be sure to fill in the pukas with more soil. It is, though, a good practice to repot these ferns every year or two because they will become root bound and plantlets will begin to appear from the drainage holes. [David Eickhoff, Native Plants Hawaiʻi]

They do very well in the landscape as a groundcover in a rich organic mix in moist, but not soggy, soil. [4] With some sun protection, such as under tall shrubs or trees, the plants will remain vibrant dark green. Sometimes they will even climb trees. [David Eickhoff, Native Plants Hawaiʻi]

Does very nicely on north and east facing locations, but plants grown on the west and south sides will get scorched if not protected, especially during the intense summer months. [David Eickhoff, Native Plants Hawaiʻi]

ʻŌkupkupu, like the Boston fern, makes a wonderful indoor plant and is listed as safe or nontoxic for children, cats and dogs. [5,6]

Plant Produces Flowers

No

leaf Leaf Characteristics

Plant texture

No data available.

Leaf Colors

  • Dark Green
  • Medium Green

leaf Pests and Diseases

Additional Pest & Disease Information

Mealybugs can be a nuisance and should be treated right away. Occasionally, caterpillars can damage the fronds. Look for curled fronds with webbing for the pest.

leaf Growth Requirements

Fertilizer

13-13-13 slow release fertilizer every six months for plants in pots or planted in the ground. For larger potted ferns showing poor color or not producing crosiers (fiddleheads or emerging fronds) use a complete fertilizer at half the recommended strength. Do not till solid fertilizers into soil since ferns have a shallow root system. [1]

ʻŌkupukupu love foliar feeding with fish emulsion and also benefit from occasional feedings with Miracle-Gro fertilizer for acid loving plants at half the recommended strength. [David Eickhoff, Native Plants Hawaiʻi]

Pruning Information

Dead fronds should be pruned off for a clean appearance.

Water Requirements

  • Moist

Additional Water Information

ʻŌkupukupu does well in moist, but not soggy, conditions.

Soil must be well drained

Yes

Light Conditions

  • Partial sun
  • Shade

Additional Lighting Information

While these ferns can occasionally be seen growing in fun sun conditions in their natural habitat, they seem to perform best under partial sun or shady conditions which will produce dark bright green foliage that these lovely fens are famous for. [David Eickhoff, Native Plants Hawaiʻi]

Spacing Information

ʻŌkupukupu can be spaced at 3 to 4 feet apart for a dense groundcover; further apart 5 or 6 feet to show case their beutiful sweeping fronds. [David Eickhoff, Native Plants Hawaiʻi]

Soils

  • Cinder
  • Organic

Limitations

The Boston fern (Nephrolepis exaltata) is considered somewhat drought tolerant. [4] But our native subspecies tend to do best with at least some reliable source of moisture.

leaf Environmental Information

Natural Range

  • Niʻihau
  • Kauaʻi
  • Oʻahu
  • Molokaʻi
  • Lānaʻi
  • Maui
  • Hawaiʻi

Natural Zones (Elevation in feet, Rainfall in inches)

  • Less than 150, 50 to 100 (Mesic)
  • Less than 150, Greater than 100 (Wet)
  • 150 to 1000, 50 to 100 (Mesic)
  • 150 to 1000, Greater than 100 (Wet)
  • 1000 to 1999, 50 to 100 (Mesic)
  • 1000 to 1999, Greater than 100 (Wet)
  • 2000 to 2999, 50 to 100 (Mesic)
  • 2000 to 2999, Greater than 100 (Wet)
  • 3000 to 3999, 50 to 100 (Mesic)
  • 3000 to 3999, Greater than 100 (Wet)
  • 4000 to 4999, 50 to 100 (Mesic)
  • 4000 to 4999, Greater than 100 (Wet)

Habitat

  • Epiphyte
  • Lithophyte
  • Terrestrial

Additional Habitat Information

ʻŌkupukupu is a common fern found on all the Main Islands except Kahoʻolawe from about 80 to nearly 4600 feet in mesic, wet and upper elevation dryland forests.

They usually can be found growing on the ground as a terrestrial, but also over or in cracks of mossy boulders and as an epiphyte climbing up trees or in crotches of trees with debris. [David Eickhoff, Native Plants Hawaiʻi]

leaf Special Features and Information

General Information

ʻŌkupkupu or niʻaniʻau (Nephrolepis exaltata) belong to Lomariopsidaceae. [8] There are several common naturalized swordferns and will hybridize with the native species. This species and kupukupu (Nephrolepis cordifolia) are the only two native Nephrolepis in the Hawaiian Islands. However, some question whether N. cordifolia is an indigneous species, but rather a  possible an early introduction.

There are also three naturalized Nephrolepis species and two localized hybrids in the islands.

The true ʻŌkupkupu has been given the name to distinguish it from the False Okupukupu (Nephrolepis multiflora). [3]

Etymology

The generic name Nephrolepis is derived from the Greek nephros, kidney, and lepis, scale, in reference to the kidney-shaped indusia (sori covering).

The Latin specific name exaltata, raised, high, lofty, alludes to the upright fronds of this fern.

The former subspecies name hawaiiensis* is referring to the place of origin, Hawaiʻi.

Hawaiian Names:

Kupukupu is a general name for ferns on a single stem. [11]

Palapalai is a Niʻihau name.

Pāmoho is also the Hawaiian name for an indigenous spleenwort fern Asplenium unilaterale.

_____

* No longer considered as an endemic subspecies. Status is currently as indigenous.

Background Information

There is a hybrid with the native Nephrolepis exaltata and the introduced Nephrolepis multiflora known as Nephrolepis x medlerae. [7]

Early Hawaiian Use

 Lei:

The fronds were fashioned as into lei for the wrists and ankles called kūpeʻe or as haku for the head. [9]

Medicinal:

The fern was used medicinally to treat a number of skin disordes by means of bathing in the processed juice. [10]

Religion:

The Hawaiian name kupu means "to sprout." The early Hawaiians would place kupukupu on hula altars so that knowledge would sprout.

Modern Use

There are nearly one hundred cultivars that exist for this species. A few of the more popular cultivars (cv.) seen in Hawaiʻi are the Boston fern cv. 'Bostoniensis', cv. 'Fluffy Ruffles', cv. 'Rooseveltii', and cv. 'Smithii.' [2]

 

Additional References

[1] Kay Lynch, Lāʻau Hawaiʻi
[2] http://www2.bishopmuseum.org/HBS/botany/cultivatedplants/ [Accessed on 10/1/08]
[3] "Hawaiʻi the Fires of Life--Rebirth in Volcano Land" by Garrett A. Smathers and Dieter Mueller-Dombois, page 127.

[4] http://www.floridata.com/ref/N/neph_exa.cfm [Accessed on 12/21/09]

[5] http://www.earthcouncil.net/freshair.htm [Accessed 12/22/09]

[6] http://www.ladybug.uconn.edu/hotissues/SafeandPoisonousHouseplants.html [Accessed 12/22/09]

[7] "The World of Ferns: Checklist of World Ferns" http://homepages.caverock.net.nz/~bj/fern/nephrolepis.htm [12/27/09]

[8] Taxon 55 August 2006: Fern Classification, by Alan R. Smith et al., page 14.

[9] "Nā Lei Makamae--The Treasured Lei" by Marie A. McDonald & Paul R. Weissich, pages 59-60.

[10] "Native Hawaiian Medicine--Volume III" by The Rev. Kaluna M. Kaʻaiakamanu, page 66.

[11] Hawaiian Dictionaries online http://wehewehe.org [Accessed 11/29/11]

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