HāPu‘U Pulu

cibotium glaucum

The HāPu‘U Pulu (Cibotium glaucum) is a magnificent tree fern endemic to the Hawaiian Islands, where it serves as a keystone species of the wet montane rainforests. Reaching impressive heights, this ancient plant is famous for the soft, woolly, golden-brown fibers called "pulu" that wrap around its young, coiled fronds (fiddleheads). It plays an essential role in its ecosystem by acting as a living substrate, with its moist, fibrous trunk serving as a natural nursery for many native Hawaiian plants and epiphytes. Historically, Native Hawaiians and later settlers harvested the silky pulu for bedding stuffing and wound dressings. Today, it remains a symbol of Hawaii's lush, primordial wilderness, contributing significantly to forest water retention and biodiversity.

Habitat: Found in wet, tropical montane forests and rainforest understories across the Hawaiian Islands, thriving in areas with high rainfall and organic soils.

Appearance

This large, slow-growing tree fern typically features a stout, upright trunk reaching 2 to 7 meters in height, crowned by a dense canopy of arching, lacy fronds that can span up to 3 meters in length. The tri-pinnate fronds are a rich, vibrant green on their upper surfaces, while their undersides exhibit a distinctive pale, glaucous bluish-green hue. The base of the leaf stalks is heavily clothed in a thick, velvety mass of golden-brown, silky hairs, which immediately distinguishes this species from other native ferns. Young fronds emerge as tightly coiled, woolly fiddleheads before unfurling into large, delicate leaf structures.

KingdomPlantaePhylumTracheophytaClassPolypodiopsidaOrderCyathealesFamilyCibotiaceaeGenusCibotium

Photo: no rights reserved, uploaded by Zoltán StekkelpakCC0 · iNaturalistView original ↗

HāPu‘U Pulu

Interesting facts

During historical times of famine, the starch-rich core of the trunk and young fiddleheads were baked and eaten as emergency food.

In the 19th century, tons of the silky pulu fiber were commercially harvested and shipped to California to stuff pillows and mattresses.

In traditional Hawaiian medicine, the soft pulu fibers were applied directly to wounds to absorb blood and promote clotting.

Special abilities

Its fibrous, moisture-wicking trunk provides a highly hospitable, damp microhabitat that allows other native plants and mosses to germinate and grow on it.

The thick layers of silky pulu hairs collect condensation and rainwater, protecting the vulnerable young fiddleheads from desiccation.

Produces millions of tiny, lightweight spores that are easily carried by tropical forest breezes over vast volcanic landscapes.

Measurements & details

Length: 200-700 cm
Lifespan: 50-150 years

Diet & Feeding

As a photosynthetic plant, it generates its own sugars using sunlight, water, and carbon dioxide, while absorbing water and key minerals through its shallow root system.

Primary Foods

Sunlight
Water
Carbon Dioxide
Nitrogen
Phosphorus
Potassium

Ecological connections

Mutualism

‘Ōhi‘a Lehua

Metrosideros polymorpha

Often begins life as an epiphyte on the fibrous trunk of the tree fern before growing roots into the forest floor.

Mutualism

‘I‘iwi

Drepanis coccinea

Uses the dense canopy of the tree fern for nesting and seeks out insects among its fronds.

Traits

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Also known as

No aliases listed yet.

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Safety

Danger

1/5 · Very low

No special safety notes yet.

Frequently Asked Questions

How to identify HāPu‘U Pulu?

Compare frond shape, how the leaflets are arranged, the stalk, and any spore clusters you can see. A single detached leaflet often hides the plant's overall growth pattern. Fern Identifier: upload a photo and compare the visible details.

How long is HāPu‘U Pulu?

200-700 cm

How long does HāPu‘U Pulu live?

50-150 years

What does HāPu‘U Pulu eat?

As a photosynthetic plant, it generates its own sugars using sunlight, water, and carbon dioxide, while absorbing water and key minerals through its shallow root system.

Where is HāPu‘U Pulu usually found?

Found in wet, tropical montane forests and rainforest understories across the Hawaiian Islands, thriving in areas with high rainfall and organic soils.