Adiantum capillus-veneris

leaf Main Plant Information

Genus

Adiantum

Species

capillus-veneris

Hawaiian Names with Diacritics

  • ʻIwaʻiwa
  • ʻIwaʻiwa hāwai
  • ʻIwaʻiwa kahakaha

Hawaiian Names

  • Iwaiwa
  • Iwaiwa hawai
  • Iwaiwa kahakaha

Common Names

  • Black maidenhair
  • Maidenhair fern
  • Southern maidenhair
  • Venus' hair fern

leaf Plant Characteristics

Distribution Status

Indigenous

Endangered Species Status

No Status

Plant Form / Growth Habit

  • Non-Woody, Clumping

Mature Size, Height (in feet)

  • Shrub, Dwarf, Less than 2
  • Shrub, Small, 2 to 6

Mature Size, Width

ʻIwaʻiwa has a spread of about 12 to 18 inches or more.

Life Span

Long lived (Greater than 5 years)

Landscape Uses

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

Additional Landscape Use Information

This graceful fern is excellent for shady, moist situations where many other plants may not thrive. If conditions are continually moist, new ferns will appear.

ʻIwaʻiwa can be used as a beautiful indoor plant and looks nice either in a standard pot or a hanging basket with semi-shady to indirect sunlight locations.

This fern appears to have a high tolerance for limestone (calcium carbonate) soils and may explain why it does so well on wet, mossy concrete bricks. [David Eickhoff, Native Plants Hawaiʻi]

Even though this fern is found in many parts of the world, please acquire native ʻiwaʻiwa to keep the gene pool local.

Plant Produces Flowers

No

leaf Leaf Characteristics

Plant texture

  • Fine

Additional Plant Texture Information

There are some non-native cultivars of Adiantum capillus-verneris such as cv. 'Fimbriatum,' and cv. 'Mairisii.' [2]

Leaf Colors

  • Light Green
  • Medium Green

leaf Pests and Diseases

Additional Pest & Disease Information

Scale and mealybugs.

leaf Growth Requirements

Fertilizer

Limestone may be added to enrich the soil.

Pruning Information

Cut off dead frond material for a clean appearance.

Water Requirements

  • Moist

Additional Water Information

Does best from moist to wet conditions and should be watered daily. If it is deprived of water for too long, the fronds will go limp and eventually die. If this happens, trim off dead plant material and resume watering. New shoots will form and your ʻiwaʻiwa will return to its former glory. [David Eickhoff, Native Plants Hawaiʻi]

Soil must be well drained

Yes

Light Conditions

  • Partial sun
  • Shade

Spacing Information

If used as a groundcover, space them at a foot or more. With sufficent moisture this fern will produce many keiki.

Tolerances

  • Waterlogged Soil

Soils

  • Cinder
  • Organic
  • Coral

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)

Additional Habitat Information

ʻIwaʻiwa is found from sea level to over 1400 feet in shaded areas, coastal seeps and on Kauaʻi and Molokaʻi in sea caves. This an uncommon to rare fern in the Hawaiian Islands and is increasingly becoming scarce here. It known only from one location on Oʻahu.

This is a common to rare maidenhair fern found worldwide. In the U.S., this species in Kentucky is considered threatened and in North Carolina it is endangered. [4]

leaf Special Features and Information

General Information

ʻIwaʻiwa (Adiantum capillus-veneris) is the only native maidenhair fern in the islands. There are, however, several other non-native species, including the more agressive delta maidenhair (Adiantum raddianum), a naturalized species. But because the two species have different habitats, there probably not much competition between them.

The other maidenhair ferns found in Hawaii are two naturalized species, the rough maidenhair (Adiantum hispidulum) and the brittle maindenhair or ʻiwaʻiwa hāuli [3] (A. tenerum); and one horticultural escapee, Adiantum 'Edwinii'.

ʻIwaʻiwa can be recognized by the fan-shaped viened fronds and pinnule (section of the frond); and by the rectangular or bar-shaped sori (spore collection) on the underside of the frond tips.

The Greek genus name, adiantos, means unwetted, and ancient name alluding to the water-repellent fronds. The Latin species name comes from capillus, hair, and venereus, of Venus.

Early Hawaiian Use

The shiny dark brown to purplish black stipes (petiole or stem of the frond) were used woven in lau hala mats and purses to create design. [5]

Early Use:

Outside of the Hawaiian Islands maidenhair fern was used to some extent by diverse cultures around the world such as Brazil, Egypt, England, India, Iraq, Mexico, Peru and the U.S. The ancient Greeks made tea from the this fern as an expectorant for coughs. European medieval herbalists used it for treating severe respiratory such as for pleurisy, but it was not very effective since the fern is not a potent herb for this medical use. [6,7,8]

The 18th-century herbalist K'Eogh stated: "It helps cure asthma, coughs, and shortness of breath. It is good against jaundice, diarrhea, spitting of blood and the biting of mad dogs. It also provokes urination and menstruation and breaks up stone in the bladder, spleen and kidneys." [7]

Modern Use

This fern is still used and prescribed by many Western herbalists for treating coughs, bronchitis, reducing excess mucus, chronic nasal congestion, and to ease sore throats. [6]

Additional References

[1] Kay Lynch, Lāʻau Hawaiʻi
[2] http://www2.bishopmuseum.org/HBS/botany/cultivatedplants/?pge=2&str=adiantum&fld= [Accessed on 11/10/08]

[3] "Hawaiian Dictionary" by Mary K. Pukui & Samuel H. Elbert, page 104.

[4] http://plants.usda.gov/java/profile?symbol=ADCA [Accessed on 5/05/10]

[5] "A Hiker's Guide to Trailside Plants in Hawaiʻi" by John B. Hall, page 199.

[6] www.herbs2000.com [Accessed 5/05/10]

[7] "DK Natural Health Encyclopedia of Herbal Medicine" by Andrew Chevallier, page 160.

[8] Raintree Nutrition Tropical Plant Database http://www.rain-tree.com/avenca.htm [Accessed on 5/05/10]

Special Notes and Information

ʻIwaʻiwa (Adiantum capillus-veneris) is the only native maidenhair fern in the islands. There are, however, several other non-native species, including the more agressive delta maidenhair (Adiantum raddianum), a naturalized species. But because the two species have different habitats, there probably not much competition between them.

The other maidenhair ferns found in Hawaii are two naturalized species, the rough maidenhair (Adiantum hispidulum) and the brittle maindenhair or ʻiwaʻiwa hāuli [3] (A. tenerum); and one horticultural escapee, Adiantum 'Edwinii'.

ʻIwaʻiwa can be recognized by the fan-shaped viened fronds and pinnule (section of the frond); and by the rectangular or bar-shaped sori (spore collection) on the underside of the frond tips.

The Greek genus name, adiantos, means unwetted, and ancient name alluding to the water-repellent fronds. The Latin species name comes from capillus, hair, and venereus, of Venus.

Early Hawaiian Use:

The shiny dark brown to purplish black stipes (petiole or stem of the frond) were used woven in lau hala mats and purses to create design. [5]

Early Use:

Outside of the Hawaiian Islands maidenhair fern was used to some extent by diverse cultures around the world such as Brazil, Egypt, England, India, Iraq, Mexico, Peru and the U.S. The ancient Greeks made tea from the this fern as an expectorant for coughs. European medieval herbalists used it for treating severe respiratory such as for pleurisy, but it was not very effective since the fern is not a potent herb for this medical use. [6,7,8]

The 18th-century herbalist K'Eogh stated: "It helps cure asthma, coughs, and shortness of breath. It is good against jaundice, diarrhea, spitting of blood and the biting of mad dogs. It also provokes urination and menstruation and breaks up stone in the bladder, spleen and kidneys." [7]

Modern Use:

This fern is still used and prescribed by many Western herbalists for treating coughs, bronchitis, reducing excess mucus, chronic nasal congestion, and to ease sore throats. [6]

Landscape Use:

This graceful fern is excellent for shady, moist situations where many other plants may not thrive. If conditions are continually moist, new ferns will appear.

ʻIwaʻiwa can be used as a beautiful indoor plant and looks nice either in a standard pot or a hanging basket with semi-shady to indirect sunlight locations.

This fern appears to have a high tolerance for limestone (calcium carbonate) soils and may explain why it does so well on wet, mossy concrete bricks. [David Eickhoff, Native Plants Hawaiʻi]

Even though this fern is found in many parts of the world, please acquire native ʻiwaʻiwa to keep the gene pool local.

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