‘Hawaiian Tree Fern’
The name Cibotium glaucum derives from:
Cibotium – the Greek kibotion, a small box often used to hold medical remedies.
glaucum – is from Latin meaning blue/green or gray, in reference to the colouring on the underneath of fronds.
The common Hawaiian names for this tree fern include Hapuu, Hapuu pulu, Hapuupuu, Pepee. Other common names include ‘blonde tree fern’ and ‘female tree fern’.
Cibotium glaucum is a tropical species found in the following Hawaiian Islands, Kaua’i, O’ahu, Moloka’i, Lana’i, Maui and Hawai’i. The species is usually found in the damp forests at altitudes between 150-2000m. The tolerance of low altitude habitats makes this the most common tree fern of the Hawaiian Islands. The species is not hardy and will not tolerate any frost.
Cibotium glaucum is a slow growing rhizome forming fern. Overtime it will produce a prostrate trunk covered in mustard/brown hairs, with the trunk reaching 3m (10ft) in height. Like many Cibotium species the plant is very slow growing, putting on only about an inch of trunk every year. Fronds can grow to reach 3m x 16cm (10ft x 6 inches) and are a light green when mature. The undersides of fronds have a distinctive glaucous (light blue green colour) and are usually covered with fine pale hairs.
The soft hairs around the base of the fronds, were used by early Hawaiians for dressing wounds and embalming bodies. Hawaiians have also eaten the uncoiled fronds (croziers), which were considered delicious when boiled. The starchy core, though, was famine food. But it was considered the most important food in lean times and one trunk may contain 50-70 pounds of almost pure starch.
The export of soft hairs from the frond bases, had a negative impact on the Hawaiian forests. These hairs or ‘Pulu’ were gathered for pillow and mattress stuffing material. Tall tree ferns were cut down to gather the pulu more easily. From 1851 to 1884, several hundred thousand pounds of pulu were collected annually from the Kilauea region on Hawaii Island and shipped to North America with a peak in 1862 of over 738,000 lbs. From 50-75 people worked at the “Pulu Factory” in now Hawaii Volcanoes National Park. After 1865, the exporting decreased until finally in the 1880’s superior stuffing materials replaced pulu.
Then around 1920, a brief period of demand for the starchy cores for commercial laundry and cooking starch surfaced. The onslaught seriously altered the native forests by removing the understory and thus making room for alien species to invade the forests. Pulu gathers often would often kill the entire plant for the pulu on the top.
Extract taken from “Alteration of Native Hawaiian Vegetation–Effects of Humans, Their Activities and Introductions” by Linda W. Cuddihy & Charles P. Stone.
Cibotium glaucum can tolerate full sun but it is wise to shelter the plant from the midday sun, the species will do best in partial shade conditions. The fern will need a good level of humidity and needs to be kept moist.
This fern is only for serious collectors if grown outside of warmer climates. The species is worth trying as container grown specimen and brought under cover through winter.
Family Name: Dicksoniaceae
Common Names: Hapuu, blonde tree fern, female tree fern.
Position: Partial shade.
Soil: Humus-rich, neutral to acid soil.
Growth Rate: slow.
Eventual spread: 6m.
Max Height: 3m.
Hardiness: Not hardy.
Summer tips: Keep the plant well watered and out of the midday heat