Native Plants of Hawai‘i - Cibotium chamissoi

Cibotium chamissoi

Cibotiaceae or Tree fern family

Synonyms: Cibotium hawaiense, Cibotium menziesii sensu Skottsb., Cibotium splendens, Dicksonia chamissoi, Dicksonia splendens, Pinonia splendens

Hāpuʻu

Hāpuʻupu‘u (for young plants without trunks), Pepe‘e (for young shoots)

Chamisso's tree fern, Chamisso's manfern, Hawaiian tree fern

Natural Range & Environment

Cibotium chamissoi is endemic to all the main Hawaiian Islands except Ni‘ihau, Kaua‘i, and Kaho‘olawe. It is common on O‘ahu but uncommon on all the other Islands. This hāpuʻu species is found in mesic to wet forests from 150 to 1,200 m (492 to 3,937 ft) but is less common above 800 m (2,625 ft) and occasionally seen as low as 50 m (164 ft) [Palmer 2003].

On O‘ahu, Cibotium chamissoi is usually the first Cibotium one sees when hiking up into the mountains, while a bit farther up one begins to encounter C. menziesii. Where the two species grow close to each other, you can occasionally see hybrids. Higher still, there is typically a gap with few or no hāpuʻu, followed by the dominance of C. glaucum at higher elevations [Palmer 2003].

In the 1990s, all the Cibotium species on O‘ahu were attacked by the alien two-spotted leafhopper (Sophonia orientalis), which greatly reduced the number of wild hāpuʻu. Even today, the remaining tree ferns are frequently less healthy or have smaller fronds [Palmer 2003]. Today, this leafhopper is present on all the major Hawaiian Islands from sea level to 4,000 ft (1,219 m) [Crop Knowledge Master].

One morphological feature that distinguishes Cibotium chamissoi from C. menziesii is the deep sinuses (gaps) between the pinnules, seen here and in close-up in the header. The fiddleheads (emerging fronds) of C. chamissoi, as well as the basal portion of its frond stipes, are covered with soft golden hairs. C. chamissoi has fronds that can be as much as 16 ft (5 m) long (photograph courtesy of Julien Carley-Windeler CC BY-NC 4.0). Here two large wild C. chamissoi display another common characteristic of this species, a skirt of dead fronds below the living fronds (photograph of hāpuʻu with surrounding trees courtesy of J.B. Friday ©).

Description

Cibotium chamissoi is a tree fern typically 1 to 2 m (3 to 6 ft) in height (but possibly as tall as 6 m [20 ft]) [Palmer 2003]. Research suggests that Hawaiian Cibotium grow very slowly, only increasing their height by an average of 3.8 cm (1.5 in) each year [Arcand 2013]. Based on this, large hāpuʻu are probably many decades old.

The trunk of a Cibotium tree fern is not made of bark and wood but rather is a thick, erect, fibrous rhizome with a starchy pith. It is this edible pith that makes them vulnerable to herbivory and death by feral pigs.

The fronds (blade and stipe combined) of Cibotium chamissoi can be as much as 16 ft (5 m) long [Palmer 2003]. The 2- or 3-pinnate blade is shiny green on top and a dull lighter green on the underside; the underside is typically covered with cobweb-like hairs that can disappear with age. Developing fronds (fiddleheads) are normally covered with these cobweb-like hairs (see photograph above). A key characteristic of this species, which separates it from C. menziesii and C. nealiae, is its deep, narrow-angled sinuses (gaps) between the pinnules (final division of a compound blade), cutting nearly to the costa (main axis of a pinna) versus cutting only ⅓ to ⅔ of the way in C. menziesii and C. nealiae. A key characteristic of C. chamissoi, which separates it from C. glaucum (which also has deep narrow-angled sinuses), is that C. glaucum has a sharp-pointed auricle (an ear-looking structure) on the most basal pinnule, while C. chamissoi does not [Palmer 2003].

The frond stipes of Cibotium chamissoi are usually naked except near their base, where they are covered with gold-colored hairs. Another common characteristic is that the old dead fronds are retained, forming a skirt around the base of the fern.

The sori of Cibotium chamissoi, like the other Hawaiian Cibotium species, are along the margin of the pinnules, nearer the inner portion of the sinus. The indusia (an outgrowth of the blade that covers the sorus) are made up of two thick tongue-shaped valves extending out from the underside of the pinnule.

Misidentification errors in 1930 and 1942 resulted in the mislabeling of some herbarium collections of C. chamissoi and general confusion with this species' taxonomy (see Synonyms above). Refer to Palmer [2003] for a full discussion of these.

Growth Requirements

General

Gone are the days when you could pick up a sizable and cheap hāpuʻu trunk at your local garden shop or home improvement outlet and plop it into your landscape (because of the danger of accidentally transporting little fire ants or the deadly fungal disease referred to as Rapid ‘Ōhi‘a Death). Most of these hāpuʻu were the victims/refugees of land clearings for a new homestead or road on Hawai‘i Island. Today, a few local growers have taken up the challenge of growing hāpuʻu from spores, a difficult and time-consuming task. We need to encourage these growers and others, both verbally and with our dollars, so we can continue to place these majestic endemic tree ferns in our landscapes.

Of the four endemic Hawaiian Cibotium species, C. glaucum (hāpuʻu pulu) is most commonly seen in private and public landscapes. This may be because it was the most common hāpuʻu harvested and sold in the past. Or it may be because it is the most environmentally adaptable of the four species, able to survive in hot, sunny lowlands nearly as well (with the proper care) as it does in cool, cloudy uplands. However, C. chamissoi can also survive in lowland landscapes, provided it is properly placed and cared for. Hāpuʻu can be used as an accent in a landscape, kept in a large container, or planted en masse for screening. While tempting, we strongly discourage you from buying or planting the highly invasive Australian tree fern (Sphaeropteris cooperi) as a hāpuʻu substitute. This alien fern has invaded Hawai‘i's native forests, where it aggressively competes with native Hawaiian plants. Fortunately, it is illegal today to sell Australian tree ferns. However, unfortunately, people are still finding ways of obtaining them.

Cibotium chamissoi cannot endure prolonged exposure to direct sunlight when planted in a dry lowland landscape; you'll see significant burning of its fronds. Therefore, in these landscapes, be sure to place your hāpuʻu in a site with constant but light shade. In contrast, in cooler or very cloudy (and rainy) locations, hāpuʻu can survive when planted in a site with some direct sunlight.

Cibotium chamissoi is typically the first Cibotium you see on a hike up into the mountains on O‘ahu, which means it is a bit more tolerant of heat and drought than the other hāpuʻu species. However, please remember it is still a fern with shallow roots (and no taproot), and, therefore, you should always avoid letting the soil surrounding your hāpuʻu dry out. In dry lowland locations, it's best to water your hāpuʻu every day (or every other day). In upland or wetter places, you can likely get by watering your hāpuʻu weekly or, maybe, even less. Always try to water your hāpuʻu from above (e.g., with sprinklers) so both the fronds and trunk (particularly the top where the new fronds are developing) get wetted every time. I (Koebele) have also found that in addition to its regularly watering, it helps if you briefly wet down your hāpuʻu and the surrounding landscape during midday to reduce the air temperature and increase the humidity.

As mentioned, Cibotium chamissoi can tolerate some drying and heat, as well as a bit of wind, but normally does better when it encounters none of these stresses. Hāpuʻu does best in organic or cinder-rich soils, but it can also survive in clay-dominant soil. However, whatever the soil type, make sure it drains water easily. For containerized hāpuʻu, I (Koebele) have used an equal mix of sphagnum peat moss and black cinders; I don't think the percentages are critical.

Under ideal conditions, young trunkless Cibotium chamissoi can grow rather quickly, putting out several moderate-sized fronds in less than a year. However, as the hāpuʻu ʻiʻi gets older and a real trunk develops, this species (and the others) begins to grow painfully slow, adding only an inch or two in height each year. Unless grown from a mature stump, the development of the first reproductive fronds with sori can take 15 or more years [Kay Lynch, per. comm.]. Unfortunately, this is just part of their biology, and no amount of sun, water, or fertilizer appears to dramatically quicken their growth.

Hāpuʻu in the ground don't seem to require fertilizer. For container plants, apply a balanced controlled-release fertilizer with minor elements about every six months, or use a foliar organic or inorganic fertilizer diluted to ⅓ to ½ the recommended strength every couple of months. When applying the controlled-release fertilizer, just sprinkle it on the media's surface and water it in; DO NOT till (i.e., mix) the fertilizer into the media because this can damage the fern's shallow, fibrous root system.

Cibotium chamissoi tends to form a natural skirt of dead fronds (see photographs above), one of the common characteristics of this species in its natural habitat. It's your call if you find this feature attractive or ugly. If ugly, remove the old fronds with hand-pruners, being careful not to damage the fern's trunk or emerging side shoots.

Pests and Diseases

In the 1990s, all the Cibotium species on O‘ahu were attacked by the alien two-spotted leafhopper (Sophoria orientalis; syn: Sophonia rufofascia), which greatly reduced the number of wild hāpuʻu [Palmer 2003]. Today, this leafhopper is present on all the major Hawaiian Islands from sea level to 4,000 ft (1,219 m) [Crop Knowledge Master]. We have never seen this leafhopper species on our hāpuʻu. However, if the fronds of your hāpuʻu begin to turn yellow or die, inspect them closely for this pest.

Wild hāpuʻu are regularly eaten and killed by feral pigs. Therefore, if you live near a forested area, remain vigilant of this potential threat, and, maybe, erect some type of barrier around your hāpuʻu. Also keep an eye out for termites, which sometimes invade the trunk.

Photograph courtesy of W. Naganime ©.

Feral pig damage to a hāpuʻu. Note the standing water in the hollowed-out trunk where mosquitoes will lay their eggs (photograph courtesy of Scot Nelson Public domain).

Uses

Ancient Hawaiian

It is difficult, if not impossible, to assign species-specific uses for the four endemic Hawaiian Cibotium species because of their overlapping Hawaiian names. Therefore, the following is a summary (with as much species specificity as possible) of all the uses we were able to find for hāpuʻu, hāpuʻu ʻiʻi, hāpuʻu pulu, hāpuʻupuʻu, pepe‘e, ʻiʻi, and ʻiʻiʻi from credible ethnobotanical literature.

In ancient and more modern times, Hawaiians enjoyed eating the uncoiled fronds of hāpuʻu when boiled. In contrast, the center of the trunk was only consumed during times of famine or fed to pigs; a single trunk could yield 50 to 70 pounds (23 to 32 kg) of sustaining starch [Handy & Handy 1972]. Preparation involved peeling away the young fronds and cooking the entire trunk in an ʻimu (underground oven) or volcanic steam vent [Mitchell 1992].

There is a Hawaiian saying: "He hāpuʻu ka ʻai he ai make," which translates to "If the hāpuʻu is the food, it is the food of death." The meaning behind this saying is that while the starchy center of hāpuʻu could be eaten, it sometimes took more than three days to prepare and cook, during which time a person may have starved to death [Palmer 2003].

Large hāpuʻu trunks were sometimes laid horizontally along the ground to create a bin for growing uhi (yams), while the fronds were used to mulch upland fields of young kalo. The fronds were also sometimes placed between the ground or floor and a kalo pounding board to prevent dirt or stone dust from rising into the poi. Hāpuʻu fronds could be substituted for a black pig when making an offering during prayers to Lono [Handy & Handy 1972].

Hawaiians used the pulu, the soft wooly material found around the base of the fronds, to dress wounds, embalm the dead, and (possibly) to fill pillows and mattresses [Neal 1965], although Abbott [1992] states that "neither Buck nor I have located pillows actually stuffed with this material." Degener [1973] describes the embalming: "First the vital organs, throat, tongue and brain were removed. The resulting cavities were then tightly stuffed with the pulu and sewed up with olona fiber. The corpse was next wrapped in a black sheet of bark cloth, or kapa, in which state it would remain little changed for at least eight months. It thereafter was usually either buried in the ground or secreted in some cave whose entrance was in some cases later sealed with cement-like volcanic ash."

Ka‘aiakamanu and Akina [1922] describe using hāpuʻu for a variety of medical treatments, including purifying the blood, stimulating appetite, losing weight, reducing chest pain, and relieving rehardened muscles, nervousness, and tired limbs. However, we were unable to find any other reliable sources to reinforce Ka‘aiakamanu's and Akina's claims.

Modern

Starting about 1850, hundreds of thousands of pounds of pulu from hāpuʻu (primarily Cibotium glaucum but also C. chamissoi) were harvested and dried in the Kīlauea region of Hawaiʻi Island and shipped to the mainland United States each year to fill pillows and mattresses. Fortunately for the tree ferns, pulu absorbs moisture and degrades, such that these bedding items were soon filled only with pulu dust, and the industry ended in 1885. However, in 1920, hāpuʻu were again harvested, this time for their starch, which was used to produce laundry and cooking products. Again, fortunately for the hāpuʻu, this industry was short-lived [Neal 1965; Degener 1973].

Of much less detrimental consequence, the stems of young hāpuʻu fronds were used to make hats, and the trunks were/are used occasionally as fence posts or to pave forest pathways [Neal 1965].

Today, you can sometimes find cut and dried hāpuʻu trunk pieces at garden shops or online being sold as growing media, primarily for orchids and anthuriums.

Special Features and Information

General

Hāpuʻu is in the genus Cibotium, which, in turn, is the sole genus in the family Cibotiaceae. Currently (2026), the genus has 11 species, distributed between Hawaiʻi (four species and a named hybrid), Southeast Asia (five species), and the cloud forests of Central America and Mexico (two species) [WikipediA;Cibotium].

Feral pigs have had a devastating impact on hāpuʻu populations. The pigs regularly consume the starchy inner core of the fern, often leading to its death [Pratt 2005]. However, according to Little and Skolmen [1989], hāpuʻu are resilient plants and can withstand damage by cattle or uprooting by feral pigs so long as the growing tip harboring the fiddlehead(s) isn't destroyed.

The pulu, or wool, found on hāpuʻu is used by Hawaiian honeycreepers to line their nests [Pratt 2005].

A natural hybrid, Cibotium chamissoi x C. menziesii, named C. x heleniae after fern expert Daniel Palmer's wife, Helen, has intermediate characteristics between the two parent species. On O‘ahu, this hybrid occurs on most leeward ridges and the bases of windward cliffs in the Koʻolau mountain range and on Mauna Kaʻala in the Waiʻanae mountain range. It is likely also present on other Islands where the two species coexist [Palmer 2003].

ʻŌhiʻa lehua (Metrosideros polymorpha) seedlings are frequently seen growing in the moist debris collected on the top of hāpuʻu. This observation was, in ancient times, the origin of the belief that hāpuʻu were the parents of ʻōhiʻa [Little and Skolmen 1989].

Hawaiian Name

Hāpuʻu is the common Hawaiian name for all four species of native Cibotium, while two of the species, C. glaucum and C. menziesii have additional Hawaiian names [Palmer 2003]. Little & Skolmen [1989] use the names hapu‘u-‘i‘i, hei‘i, and hapu‘u ii for C. chamissoi.

In modern times, to help with the proper pronunciation, Ulukau recommends that hāpuʻu be spelled with a kahakō over the "a" (ā).

Etymology

Cibotium is from the Greek word kibotion, diminutive of kibotos, meaning "a box or casket," in reference to the indusium, a part of the fern's frond blade that covers the sorus (spores) [Gledhill 2008].

The species name, chamissoi, honors Ludolf Karl Adelbert von Chamisso (1781–1838), a French-born German explorer, naturalist, author, poet, and plant collector, who collected plants for the Russian Kotzebue expedition that visited Hawai‘i [Palmer 2003].

BPK