Sadleria cyatheoides

leaf Main Plant Information





Hawaiian Names with Diacritics

  • Maʻu
  • Maʻumaʻu
  • Puaʻa ʻehuʻehu
  • ʻAmaʻu
  • ʻĀmaʻumaʻu

Hawaiian Names

  • Amau
  • Amaumau
  • Mau
  • Maumau
  • Puaa ehuehu

Common Names

  • Rasp fern
  • Red pig


  • Blechnum fontanesianum
  • Blechnum kaulfussianum
  • Woodwardia cyatheoides

leaf Plant Characteristics

Distribution Status


Endangered Species Status

No Status

Plant Form / Growth Habit

  • Non-Woody, Clumping

Mature Size, Height (in feet)

  • Fern/Fern-like, Medium, 1 to 3
  • Fern/Fern-like, Tall, Greater than 3

Life Span

Long lived (Greater than 5 years)

Landscape Uses

  • Accent
  • Container

Additional Landscape Use Information

This rather common fern is rarely seen in private or public collections.

Plant Produces Flowers


leaf Leaf Characteristics

Plant texture

  • Coarse

Leaf Colors

  • Dark Green
  • Medium Green
  • Red

Additional Leaf Color Information

ʻAmaʻu leaves turn from bright red, magenta, rust, and/or orange when fiddles (croziers) emerge to green upon maturity.

leaf Pests and Diseases

leaf Growth Requirements


13-13-13 slow release fertilizer every six months for plants in pots. 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]

Water Requirements

  • Moist
  • Wet

Soil must be well drained


Light Conditions

  • Full sun
  • Partial sun

Additional Lighting Information

In its natural habitat at higher altitudes, it grows in full sun. But in an urban landscape, it does best with some protection from the mid-day, hot sun and perhaps should be grown in part-shade or morning sun locations.


  • Wind


  • Cinder
  • Organic

leaf Environmental Information

Natural Range

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

Natural Zones (Elevation in feet, Rainfall in inches)

  • 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)


  • Terrestrial

Additional Habitat Information

A common fern found from about 245 to over 7215 feet in exposed habitats, mesic and wet forests and shrublands, and a primary invader (pioneer) of new lava flows on all main islands, except Niʻihau and Kahoʻolawe.

leaf Special Features and Information

General Information

There are six species in the endemic fern genus Sadleria belong to the family Blechnaceae or Chain fern family.

The genus Sadleria can easily be divided into two distinct groups: the Cyatheoides group of medium- to large-sized, even tree, ferns found in diverse habitats from recent lava flows to mesic and wet forests, include S. cyatheoides, S. pallida, S. souleyetiana, and the rare S. wagneriana; and the Squarrosa group of small ferns of dark, wet banks, include S. squarrosa and S. unisora.


The generic name Sadleria is named after Dr. Joseph Sadler (1791-1849), a physician who studied the ferns in his native Hungary.

The specific epithet cyatheoides is named after Cyathea, a tree fern genus, and the Greek oides, resembling, probably alluding to a similarity in habit to tree ferns.

Hawaiian Names:

ʻĀmaʻumaʻu is also the name for young ʻamaʻu ferns; many (plural) ʻamaʻu ferns, ferny, abounding in ʻamaʻu ferns; a covering of ʻamaʻu ferns (preceded by ke). [12]

Maʻu is the same as ʻamaʻu. [12]

Maʻumaʻu is the same as ʻāmaʻumaʻu. Halemaʻumaʻu (name of the pit at Kīlauea Crater), means "ʻāmaʻu fern house" or "home of the ʻāmauʻmau." [5,12] ʻĀmaʻumaʻu (Sadleria cyatheoides) can be seen growing in Kīlauea Crater and around Halemaʻumaʻu.

Puaʻa ʻehuʻehu means "red pig." [12]

Background Information

This beautiful native fern is one of the first plants to pioneer fresh lava flows. They can grow in desert areas, as well as in moister areas and dense rain forests, as well as on rocky cliffs of canyons. [11]

Sadleria spp. may hybridize among themselves in any combination of species, though none it seems have been formally named as yet.

Early Hawaiian Use

Unless otherwise specified, the following uses by early Hawaiians were for ʻAmaʻu (Sadleria spp.) in general:


The leaves, or fronds, were also used as mulch in gardens and dry-land kalo (taro) in drier parts of the islands. [5,8,11] In drier regions, fronds were laid over prepared ground. When the rains came, the fronds were removed, and seeds planted. After the rain, fronds were replaced as mulch to cut down evaporation. [11]

After harvesting the leaves, the wound of the fern was covered so that the plant would not die. [9]

Pukui mentioned of ʻamaʻu: "Hui ka lau o ka ʻamaʻu i uka ka wai o kahawai." (When the leaves of ʻamaʻu turn toward the upland, it is a sign of flood). When the wind blows the leaves of the ʻamaʻu fern so that they bend toward the mountains, it is also blowing clouds inland, which will produce rain. [13]


A red dye was extracted from the young fronds as well as the cortex of trunks of larger plants for kapa (tapa). [2,10] Leafstalks were beaten and used as sizing with bark in kapa making. [8] The sticky, pulpy sap from the open or rolled-up fronds* sometimes used in the kapa making process to keep the pulp moist and together or to act as a type of glue to weld strips kapa together or to repair kapa. [2,10]

Older stems were used for sizing kapa (tapa). [11]


The fronds of ʻamaʻu were used as a temporary shelter in the forest, or as thatch for trim on corners or ridges, tied lenghthwise, as a waterproofing in these areas. Fronds, along with lau hala (Pandanus tectorius) or by themselves, were used for the entire roof thatching or even the walls, if pili (Heteropogon contortus) was scarce. [5,8,11]


ʻAmaʻu was an important famine food for the early Hawaiians or fed to pigs. [6,7] The starchy pith was occasionally cooked in an ʻimu, and the young shoots eaten raw or cooked. [2,5] Plants were powdered to make a beverage similar to tea or coffee. [3]

Household Furnishings:

The pulu (fuzzy hairs around emerging fronds or leaves) of ʻamaʻu, called pulu ʻamaʻu, resembles hāpuʻu (Cibotium spp.) and was also used as stuffing for pillows and mattresses. [5,11]


The plants with other ingredients were pounded to make a juice applied to boils and pimples. The shoots were used for lung troubles, and inner bark pounded for asthma. [3,9] Leaves used for gout. [9] The dried leaves were used to treat the illness palahū (rot) and kaoko ʻino (syphilis). [4]


To polytheistic Hawaiians, ʻamaʻu is one of the forms hat the pig demigod Kamapuaʻa assumes at will.


The ground over which aliʻi and attendants were to pass, or remain on at a dedication of heiau, was covered with ʻamaʻu fronds. [11]


* Pepeʻe a palaholo (a rolled-up frond of ʻamaʻu) describes the ʻamaʻu ferns that furnish sap used in kapa making. It implies the same thought as the saying, "Great oaks from little acorns grow."

Additional References

[1] Kay Lynch, Laʻau Hawaiʻi
[2] "Plants in Hawaiian Culture," by Beatrice H. Krauss, pages 15, 64, 65, 323.

[3] "Hawaiian Herbs of Medicinal Value," by D.M. Kaaiakamanu & J.K. Akina, page 16.

[4] "Native Hawaiian Medicine--Volume III" by The Rev. Kaluna M. Kaʻaiakamanu, page 45.

[5] "In Gardens of Hawaii" by Marie C. Neal, pages 22-23.

[6] "Resource Units in Hawaiian Culture" by Donald D. Kilolani Mitchell, page 128.

[7] "Lāʻau Hawaiʻi: Traditional Hawaiian Uses of Plants" by Isabella Aiona Abbott, page 43.

[8] "Common Forest Trees of Hawaii (Native and Introduced)" by Elbert L. Little Jr. and Roger G. Skolmen, page 40.

[9] "Listen to the Forest" video and narration by Eddie Kamae. Interview with Henry Auwae, Kahuna Lāʻau Lapaʻau. [Accessed on 5/27/13]

[10] Haleakalā National Park [Accessed on 7/16/13]

[11] "Ethnobotany of Hawaii" by Beatrice H. Krauss, page 81.

[12] Hawaiian Dictionaries online [Accessed 4/10/14]

[13] "ʻŌlelo Noʻeau: Hawaiian Proverbs and Poetical Sayings" by Mary Kawena Pukui.



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