Carnauba Palms and Candelilla: The Plants and Their Wax
Carnauba palms and candelilla shrubs are interesting plants that produce a useful wax. Carnauba palms are native to Brazil. They grow in the wild, but the area around the trees is often managed to some extent. Candelilla is a shrub native to northern Mexico and the southwestern United States. The wax is obtained from wild plants. The shrub is sometimes grown in gardens.
Wax is produced on the surface of leaves and nonwoody stems and on the surface of certain fruits. It acts as a waterproofing agent that protects plants from dehydration. Some plant waxes have properties that are beneficial for humans. Carnauba and candelilla wax are examples of these helpful materials.
The Waxy Cuticle of Plants
The cuticle is a protective layer on the top and bottom of a leaf and on the surface of nonwoody stems. It's waxy and water-repellent. The cuticle is produced by the cells in the epidermis, which is the outer cell layer of leaves and nonwoody stems.
The cuticle has a complex chemical structure that hasn't been fully deciphered. Its base consists of a substance called cutin. On top of the cutin and interwoven with it are fatty acids, alcohols, hydrocarbons, and other organic (carbon-containing) molecules, which form the wax. The layer overlying the cutin is known as the "cuticle proper" and is the part that is removed during wax collection from a plant.
Small openings called stomata (or stomates) are located in the epidermis. The cuticle is absent over the surface of a stoma. Carbon dioxide, oxygen, and other gases move into and out of the leaf through the stomata, which are mostly located on the underside of the leaf. Here the environment is generally shady and the rate of water evaporation from the leaf is lower than it would be on the upper surface. A stoma is bordered by guard cells which can close the opening when necessary.
The Carnauba Palm
The carnauba palm is native to the northeastern part of Brazil. It's also known as the carnauba wax palm and the Brazilian wax palm. It has the scientific name Copernicia prunifera. It's sometimes referred to as Copernicia cerifera, however. It belongs to the family Arecaceae, which contains other palms.
The tree grows on the savanna or in open forest. It has the ability to withstand dry periods as well as occasional flooding. It can also withstand moderate salinity. The wax is found on its leaves and leaf stalks (petioles) and is harvested from the upper surface of the leaves.
The tree has a single trunk and generally reaches a height of up to 15 metres (49 feet). Some trees are taller. The attractive leaves are large, deeply divided, and shaped like a fan. They are green, blue-green, or light grey in colour. They are borne at the end of a long petiole, which bears spines. The plant needs to be handled carefully in order to prevent injuries from the spines. The lower two-thirds of the trunk bears leaf bases remaining after the loss of older leaves. These remnants are arranged in a spiral pattern around the trunk.
The flowers of the carnauba palm are small and yellow. They are grouped in a long and sometimes branched collection of flowers known as an inflorescence. The oval fruits are yellow-green to dark brown in colour, depending on their maturity.
Harvesting Carnauba Wax
The first step in harvesting carnauba wax is to strip leaves from the tree. If this is done carefully, it doesn't damage the plant, which grows new leaves. The best wax comes from young, unopened leaves. According to one Brazilian company involved in the wax extraction, harvesters use a long stick with a knife at the end to reach the leaves.
Once the leaves have been removed, they are dried in the sun. The wax is then mechanically removed from the surface of the leaves. A traditional method that is still used is to beat the leaves in order to separate the wax. The wax is obtained as flakes or a powder. The wax is then purified. It's often boiled in water, filtered, and then pressed. Some companies use solvent extraction to remove the wax from the liquid.
Although there is an overlap in the uses of carnauba and candelilla wax, the plants belong to different groups of flowering plants. Palm trees are monocots and candelilla is a dicot. Monocot embryos have a single cotyledon (seed leaf) and dicot embryos have two. There are additional differences between the two groups.
Uses of the Wax and the Tree
Carnauba wax is hard and has a high melting point. It's found in polish for cars, floors, furniture, and instruments. It's also used to make the shiny coating of candies, such as smarties, the coating of some medicinal tablets, the wax that coats dental floss, and candles. In addition, it's used to coat some specialized paper and cardboard products, including paper plates.
Carnauba wax is sometimes listed as E 903 on ingredient lists. The "E" stands for Europe. The designation is assigned by the European Food Safety Authority. E designations may be found in countries outside Europe, however, especially on imported food.
Carnauba wax is considered safe to eat in the amounts normally added to food. Researchers haven't investigated the effects of eating a large amount of the wax, however.
The carnauba palm is sometimes known as the "tree of life" because of its many uses. The wax is the most useful product of the plant today. The wood of carnauba palms is used to construct items such as bridges and the beams of roofs. The leaves are used to create thatch for roofs. They are also woven into items such as baskets, bags, hats, and mats. The fruits are edible but don't contain much pulp. They are used as animal feed. Each fruit contains one seed. The seeds are sometimes used as a coffee substitute.
Rhodnius prolixus is found on palm trees and is a common transmitter of the parasite that causes Chagas disease. Rhodnius nasutus is very similar in structure to the Rhodnius prolixus shown in the photo above. It's found on many carnauba palms and can also transmit the parasite.
Bugs in Palm Trees and Chagas Disease
Carnauba palms are often infested by bugs that can carry the parasite that causes Chagas disease. Some people use the word "bug" as an alternate name for insect, but according to biological classification bugs belong to a specific order of insects known as the Hemiptera.
The order Hemiptera contains a family known as the Reduviidae. This family contains a subfamily called the Triatominae. The members of the subfamily are referred to as either reduviid bugs or as triatomine bugs. Many triatomine bugs are blood suckers. Some of these bugs—including Rhodnius nasutus, which infests carnauba palms—can transmit Chagas disease. The bugs breed in the palm trees.
When a triatomine bug bites someone to obtain a meal of blood, they sometimes defecate at the same time. The feces may contain the parasite that causes Chagas disease, which is named Trypanosoma cruzi. If the parasite enters the victim's bloodstream through the wound created by the bite, it may make the person sick. The insects are often known as kissing bugs because they tend to bite people's faces while they are sleeping in order to obtain blood. The area around the bite may be swollen.
Chagas disease exists in an acute (short-lived) phase and a chronic (long-lasting) phase. During the acute phase, people may experience symptoms such as a headache, body aches, a fever, a rash, and fatigue. These symptoms eventually disappear, but the person may still have a dormant infection. In many people, there are no further symptoms from the infection. In some people, however, the parasite becomes active again and life-threatening symptoms may appear.
People who visit places where triatomine bugs that transmit Chagas disease are found should take precautions to avoid insect bites. These places include Mexico, Central America, South America, and the southern United States. People should visit a doctor if suspicious symptoms appear after a visit to the area.
The Candelilla Plant
The candalilla plant has the interesting scientific name Euphorbia antisyphilitica. The species name was chosen because the plant was once thought to fight syphilis. The plant is also known as Euphorbia cerifera. It belongs to the spurge family, or the Euphorbiaceae.
From a distance, candelilla looks as though it consists entirely of thin, blue-green stems growing in an upright bunch. Branches in the stems are uncommon. The plant does produce leaves, but they are small and hard to see. The name of the plant means "little candle" and refers to the appearance of the stems. The mature stems generally range from around one foot to two feet in height but may occasionally be as tall as three feet.
The flowers of the plant are beautiful but small. They are white or pink with a red centre surrounding yellow or green reproductive structures. They grow all along the stems.
Harvesting and Processing Candelilla Wax
Bundles of candelilla plants are collected by hand. If the root is left, the plant will likely regenerate. If the plant and the root are removed, regeneration isn't possible.
The collection and purification of wax from the plants is a multistep, arduous, and time-consuming process. The processed can be summarized as follows:
- The candelilla plants are placed in large cauldrons containing water and sulphuric acid.
- The liquid is heated and boiled. This causes the wax to separate from the plant and rise to the surface in a foam.
- The foam is removed and placed in a different container. The liquid from the foam is removed, leaving the wax behind.
- The wax is allowed to cool and solidify.
- The solid wax is broken into multiple pieces, which are melted to allow debris to separate by sedimentation.
- Melted wax is passed through Fuller's Earth or activated charcoal to purify it.
- Additional refining steps may be performed before the wax is ready to sell.
Fuller's earth is a type of clay known for its ability to absorb materials. Activated charcoal is a form of carbon that does the same thing.
Few people in this country have ever heard of candelilla wax and only a handful have seen it being produced, yet nearly everyone has had personal contact with it.— Texas Beyond History
Uses of Candelilla Wax and Plants
Candelilla wax is used to add a glaze to foods and is found in some brands of chewing gum. It may be listed as E 902 on an ingredient list. Like carnauba wax, candelilla wax is considered safe to eat in the usual quantities added to food. The wax is used in a variety of cosmetics, including lotions, creams, and lip balm. It's a good vegan substitute for beeswax.
Candelilla wax is hard after it has been refined. It's used for some of the same purposes as carnauba wax. It's added to polishes and waxes for floors and furniture and applied to leather. In addition, it's used to coat paper, cardboard, and phonograph records and is added to some lubricants and adhesives.
Candelilla is sometimes grown as a garden plant. Its flowers attract butterflies. The stems release a milky latex when cut, which may be irritating to the skin. The latex is toxic if ingested. Gloves should be warn when handling the plant.
Some Concerns About the Wax Harvest
Though the wax obtained from the carnauba palm and the candelilla plant is useful, some concerns are associated with its collection. In each case, the collection process is labour intensive. In addition, the people collecting the wax sometimes work under unpleasant conditions.
Another concern is the status of the plants. If a carnauba palm is stripped of a large quantity of leaves before they have made carbohydrates by photosynthesis, the tree may be harmed. Collecting too many candelilla shrubs with their roots attached may harm the wild population. A sustainable industry that treats humans well is important with respect to the collection of both types of wax.
- Fernández, V., Guzmán-Delgado, P., Graça, J., Santos, S., & Gil, L. (2016). Cuticle Structure in Relation to Chemical Composition: Re-assessing the Prevailing Model. Frontiers in Plant Science, 7, 427. http://doi.org/10.3389/fpls.2016.00427
- Facts about Copernicia prunifera from the Floridata Plant Encyclopedia
- Carnauba wax information and extraction from the Gustav Heess Group
- More information about the wax extraction from Carnaúba do Brasil
- Safety of carnauba wax as a food additive (abstract) from EFSA (European Food Safety Authority)
- Rhodnius nasutus on Carnauba palm trees from ARCA (a repository of Fiocruz, a public health research institution)
- Facts about Chagas disease from the CDC (Centers for Disease Control and Prevention)
- Information about candelilla plants from Arizona State University
- Facts about Euphorbia antisyphilitica from the Lady Bird Johnson Wildflower Center, University of Texas at Austin
- Extraction of candelilla wax from the Candelilla Institute
- From Desert Plants to Dollars from Texas Beyond History (A University of Texas at Austin website)
- Safety of candelilla wax as a food additive (abstract) from EFSA
© 2018 Linda Crampton