Vegetable Ivory

Wayne's WordIndexNoteworthy PlantsTriviaLemnaceaeBiology 101BotanySearch

Noteworthy Plants January 1999

Vegetable Ivory
Saving Elephants & The Rain Forest
© W.P. Armstrong (Updated 12 July 2010)

What do African elephants and the South American rain forest have in common? They are both being eliminated from the face of the earth at an alarming rate. During the past three decades, poachers in search of ivory tusks have decimated large populations of African elephants, some by as much as 50 percent. Bans on international trade of elephant ivory have discouraged the slaughter of elephants, but the demand for polished ivory has pushed the world's largest living land animal to the brink of extinction. Across the Atlantic Ocean, in a land that was once connected to the African continent, another kind of massacre is happening to the rain forest. In Central and South America this destruction amounts to about 50 acres per minute, an area roughly the size of West Virginia each year. Slash and burn agriculture is directly responsible for the extermination of hundreds of plant and animal species each year, largely for plantations of exportable products such as fast-growing pines, rubber, bananas, coffee and cattle. However, there is a glimmer of hope in this modern day battlefield of people against nature: A lovely Amazonian palm might help to save its rain forest relatives and the African elephant.

South American Vegetable Ivory

Several tropical American palms are known to produce vegetable ivory, but one of the most important is Phytelephas aequatorialis, also known as the ivory-nut palm. The generic name Phytelephas literally means "elephant plant." It is derived from the Greek words phyton (plant) and elephas (elephant). The specific epithet aequatorialis refers to the equatorial region where this palm is native. Another name used by some authors is P. macrocarpa, in which the specific epithet macrocarpa refers to the large fruits bearing ivorylike nuts. Ivory-nut palms have an extensive distribution along banks of tropical American rivers, from Panama and Colombia to Peru. They are most abundant in the Amazon Basin of Bolivia, Ecuador and Peru. The WAYNE'S WORD staff has seen this remarkable palm in Ecuador along the beautiful Napo River, a tributary of the Amazon.

A female ivory-nut palm (Phytelephas aequatorialis). The large, globose, brown structures at the base are clusters of seed-bearing fruits.

One of the best places to see the beautiful South American ivory-nut palm (Phytelephas aequatorialis), is the Napo River of Ecuador, a major tributary of the Amazon. It typically grows under large rain forest trees along streams and on wet hillsides. Large pinnate leaves up to 20 feet tall arise from a woody trunk that is often leaning or growing from a longer horizontal trunk above the moist ground. Like cottonwoods, willows, marijuana and people, ivory-nut palms are dioecious, with separate male and female individuals. Female palms bear clusters of large, brown fruits, the size of grapefruits or melons. Each fruit is studded with numerous woody, pointed horns and contains four or more large seeds. The seeds have an outer shell (seed coat) and a large white endosperm. Called "taguas" by local Indians of the Napo River, the endosperm of immature seeds is pulpy and sweet--food for people and animals of the region. Mature, dry seeds are so hard that it requires a hacksaw to cut one in half. Although the heavy seeds typically sink in water, some become buoyant due to internal cavities from endosperm decay. These buoyant seeds are washed downstream by torrential rains, eventually ending up in the Atlantic Ocean where they may drift to Caribbean Islands and beaches of the southeastern United States.

The woody, seed-bearing fruit of the ivory-nut palm (Phytelephas aequatorialis) is studded with numerous woody, pointed horns and contains four or more large seeds called tagua nuts. This fruit was collected in the lush Napo River rain forest in Ecuador. The seeds are an important source of vegetable ivory, a hard, hemicellulose substance used in carvings and scrimshaw. The endosperm of immature seeds is sweet and pulpy, and is eaten by local people and animals of the region.

Another spiny, seed-bearing fruit of the ivory-nut palm (Phytelephas aequatorialis) from the rain forest of Ecuador. The right fruit has been opened to exposed the seeds (tagua nuts).

The white, dried endosperm inside the seeds of ivory-nut palms contains a substance called hemicellulose that becomes so hard and dense that it can be carved and polished like elephant tusks. [The white "meat" inside coconuts and the exploded morsels of popcorn are also endosperm tissue.] A small cylindrical cavity near the outer edge of each ivory-nut was once occupied by the miniature palm embryo. This cavity can sometimes be found in carved objects. Called "vegetable ivory," the endosperm is used for buttons, chess pieces, dice, umbrella handles, billiard balls, and for intricate carvings in the art of scrimshaw, without endangering whales, elephants and walruses. Like wood, vegetable ivory is essentially composed of thick-walled dead cells; however, unlike grainy hardwoods it has a texture and hardness similar to ivory. In fact, vegetable ivory is remarkably dense, with a rating of roughly 2.5 on the scale of mineral hardness. [Compare this rating with 3.5 for a copper penny and 10 for diamond.] Ivory-nuts can be polished in a stone tumbler, as you would polish agates and quartz, or by using tin oxide and a buffing wheel.

An assortment of raw and polished seeds from the ivory-nut palm (Phytelephas aequatorialis). Like elephant ivory, the seeds can be fashioned into all sorts of beautiful objects, from chess pieces, buttons and pendants to knife handles and belt buckles with intricate scrimshaw designs. The workability, density and fine-grained texture is also similar to true ivory.

Ivory-nuts have been exported from South America for more than a hundred years. In fact, near the turn of the century Colombia and Ecuador were exporting nearly 40,000 tons of the precious nuts to the United States and Europe. According to an article in International Wildlife (1991) by Anne Underwood, a ship sailing from South America to Germany in 1865 carried a load of tagua nuts as ballast. Upon arriving at dockside in Hamburg, curious stevedores began playing with the taguas and noticed their ivorylike characteristics. For many years the buttons on uniforms worn by U.S. soldiers came from ivory-nuts. Like so many natural dyes and textile fibers, vegetable ivory has been replaced by less expensive synthetics. By l950, the discovery of new plastic polymers put an end to the demand for tagua nuts.

But what about the demand for elephant ivory? No artificial plastic can take its place; however, vegetable ivory is a very desirable substitute. Like elephant ivory, it is completely natural and it comes from a marvelous wild creature. Unlike elephants which must die for their precious ivory, tagua palms are a renewable resource; as long as their native habitat is preserved and sufficient seeds are left to perpetuate the palms. A single female tagua palm may produce up to 50 pounds of nuts in a year, that's roughly the amount of ivory in an average African elephant tusk. The elephant, however, yields its ivory only once while the palm produces nuts year after year.

The creation of a tree frog from a tagua nut (Phytelephas aequatorialis).

Tree frog carved from a tagua nut (Phytelephas aequatorialis) in Panamá.

Boa constrictor carved from a tagua nut (Phytelephas aequatorialis) in Panamá.

A crab carved from tagua nuts (Phytelephas aequatorialis).

Other Vegetable Ivory Palms

There are several other palm species from distant rain forests with large, extremely hard seeds that are also used for vegetable ivory. The Caroline ivory-nut palm (Metroxylon amicorum) is native to the Caroline Islands of Micronesia. The unusual one-seeded fruits are covered with numerous shiny brown scales and superficially resemble a closed pine cone. Another source of vegetable ivory is Hyphaene ventricosa, a beautiful African palm native to islands and banks of the Zambezi River in the vicinity of Victoria Falls. Although the seeds are smaller than the Caroline ivory-nut palm, the bony endosperm is just as hard. The fruits of Hyphaene palms contain a sweet, juicy outer pulp that tastes like gingerbread and is the source of the name, gingerbread palms. Unlike most other palms, they have an unusual branching growth habit resulting in forked trunks.

Fruits and seeds from two distant species of vegetable ivory palms: Metroxylon amicorum from the Caroline Islands of Micronesia (A) and Hyphaene ventricosa from the Zambezi River of Africa (B). The seeds are so hard that it takes a hacksaw blade to cut then in half.

A Caroline ivory-nut palm (Metroxylon amicorum) native to the Caroline Islands of Micronesia. The unusual one-seeded fruits are covered with numerous shiny brown scales and superficially resemble a closed pine cone.

A Caroline ivory-nut palm (Metroxylon amicorum) native to the Caroline Islands of Micronesia. The unusual one-seeded fruits are covered with numerous shiny brown scales and superficially resemble a closed pine cone. Upper Right: The seed (endosperm) has been cut in half using a hacksaw blade. Lower Right: The hard endosperm has been carved into a bowl.

  Note: A closely related species of Metroxylon called the natangura  
palm (M. warburgii) is native to Vanuatu & the Solomon Islands.


Most consumers of ivory would probably buy jewelry and carved articles made from vegetable ivory. If their greed for ivory is based on its rarity and exotic origin, then vegetable ivory should be equally acceptable. This is especially true considering the endangered status of tropical rain forests where ivory-nut palms grow. Very few ivory lovers could tell whether beautiful rings, necklaces, belt buckles and carved knife handles are made from the modified dentin of enlarged elephant incisors or the dried hemicellulose of palm seeds. The only drawback of ivory-nuts is their size. Average seeds are about two inches (5 cm) long, and this would limit the size of articles made from them. However, milled nuts can be fused into a larger, solid mass with modern bonding cements under heat and pressure.

Left Image: A lovely vegetable ivory necklace made from polished seeds of the ivory-nut palm (Phytelephas aequatorialis).

Another ecological incentive for using vegetable ivory is that renewed trade in tagua nuts could help protect endangered rain forests in Ecuador, Colombia and Peru. According to a Massachusetts-based environmental group called Cultural Survival, natural rain forest products such as vegetable ivory can generate up to five times the income of banana plantations and cattle ranches. In fact, two California-based companies, Patagonia Inc. and Smith & Hawken, use buttons made of tagua rather than plastic on their clothing products.

Buttons made from tagua nuts (Phytelephas aequatorialis).

Meanwhile the tropical forests and their inhabitants are rapidly being destroyed. Who knows what biological secrets may reside in the genes of these vanishing species--perhaps cures for many tragic human diseases. The devastation of the earth's tropical rain forests is analogous to a worldwide burning of libraries without ever reading any of the books. Maybe tagua nuts and other vegetable ivory palms can help save at least a part of these beautiful rain forests before it's too late, and at the same time help to preserve one of the most magnificent mammals that ever roamed the earth.

Seed Jewelry References

  1. Armstrong, W.P. 1991. "Vegetable Ivory: Saving Elephants & South American Rain Forests." Zoonooz 64 (9): 17-19.     

  2. Armstrong, W.P. 1991. "Beautiful Botanicals: Seeds For Jewelry." Ornament 15: 66-69.

  3. Armstrong, W.P. 1992. "Jewels of the Tropics." Terra 30: 26-33.

  4. Armstrong, W.P. 1992. "Nature's Bounty." Ornament 16: 66-69.

  5. Armstrong, W.P. 1993. "Botanical Jewelry." Herbalgram 29: 26-33.

  6. Armstrong, W.P. 1993. "Neotropical Amber." Ornament 17: 58-61.

  7. Armstrong, W.P. 1994. "Job's Tears." Ornament 18: 104-105.

  8. Armstrong, W.P. 1995. "Indian Shot." Ornament 18: 70-71.

  9. Armstrong, W.P. 1997. "Indian Shot." The New Forester (Dominica Minister of Agriculture) 9: 32-33.

Return To WAYNE'S WORD Home Page
Go To Biology GEE WHIZ TRIVIA Page