Common name: Ivory palm

Ⅰvory palm originates in the rainforests of Ecuador and is so named for its seed, which was once the main material for making clothing buttons.

It is an erect palm up to 12 m (40 ft) high, though more typically is 5 to 10 m (15 to 30 ft) tall with a stout trunk, 25 to 30 cm (10 to 12 in) in diameter and spirally ringed by leaf scars. The crown consists of large, arching fronds up to 8 m ( 26 ft) long with green leaflets arranged in pairs along the length. After they die, the leaves persist on the trunk for some time, often as a skirting below the crown.

Being a dioecious palm species, it produces female and male flowers on separate individuals. The flowers are cream-coloured and bloom mainly in the dry season, though on-and-off blooms in some parts of its range occur throughout the year. On male plants, the flowering spikes are up to 1.5 m (5 ft) long and carry between three and five hundred flowers arranged in clusters. Flowering spikes on female palms are shorter, usually only 0.5 m (1.5 ft) long, and carry much fewer flowers, around twenty to thirty.

Only female palms produce fruit, up to twenty densely packed in a cluster hanging suspended on a short stalk below the crown. The fruit are conical, up to 15 cm (6 in) in diameter, with a rough, brown fibrous exterior and have five to six large wedge-shaped seed inside.

Use

The seed are hard and heavy, white to cream coloured and similar to true ivory when polished. Suitable for hand-carving and turnery, they've been made into chess pieces, figurines, billiard balls, dice, door and drawer handles (knobs) and other articles. However, its most widespread use was making buttons for the garment industry. It is estimated that before the 1920s, around twenty per cent of all buttons produced in the United States were made from vegetable ivory.

In the past, off-cut pieces were finely ground into an edible flour exported from Ecuador to the United States and Japan. Nowadays, the off-cut pieces are mostly finely ground for use as a natural exfoliant in commercial skincare products developed by cosmetic companies.

Climate

Grows naturally in humid to very humid tropical lowland climates, generally areas with annual lows of 17 to 25°C, annual highs of 28 to 35°C, annual rainfall of 1800 to 5000 mm and a dry season of 4 months or less.

Growing

New plants are started from seed collected from wild plants, as it is not usually cultivated. It takes four to nine months or longer for the seed to germinate, and shade is necessary for its early development, with seedlings usually grown in the shadow of mature palms. 

Performs best on free-draining clay-loam and loam soils of a moderately acid to slightly alkaline nature, generally with a pH of 5.0 to 7.5, and on sites with light shade to partial sun exposure. It has good tolerance to seasonal flooding.

The fruit are harvested after they have matured and fallen to the ground. The whole fruit is then air-dried in a sheltered location for four or more weeks. After drying, it is peeled to expose the hard inner shell, which is then cracked open to extract the vegetable ivory.

Problem features

Flooding rivers overflowing their banks are perhaps the primary dispersal vehicle for the heavy seed across floodplains in its native range. And large South American rodents such as Pacas probably account for their dispersal beyond the floodplains. It is recorded as having naturalised in the Galapagos Islands. Still, there does not appear to be any record of it as a serious weed anywhere in the world.

Books

• Castner, J. L. & Duke, J. A., & Timme, S. L. 1998, A field guide to medicinal and useful plants of the Upper Amazon, Feline Press, Gainesville, Florida

• Henderson, A., Galeano, G. and Bernal, R. 1995, Field guide to the palms of the Americas, Princeton University Press, Princeton, New Jersey

• Hill, A. F. 1952, Economic botany : a textbook of useful plants and plant products, 2nd ed, McGraw-Hill, New York

• Janick, J., & Paull, R. E. 2008, The encyclopedia of fruit & nuts, CABI Publishing, Wallingford, Oxfordshire

• Randall, R. P. 2002, A global compendium of weeds, R.G. and F.J. Richardson Press, Melbourne

Articles, Journals, Reports and Working Papers

• Clay, J.W. and Clement, C.R. 1993, Selected species and strategies to enhance income generation from Amazonian forests, FAO Working Paper, Food and Agriculture Organisation of the United Nations (FAO), Rome