The vanilla orchid (Vanilla planifolia) -

A revised version of this article was published before in the "Hortus Magazine" (December 2012) of the "Botanical Garden of Amsterdam"

 by Fred Triep  

The vanilla orchid (Vanilla planifolia) is the supplier of vanilla. This orchid grows in Florida, Mexico, West Indies, Central America and northern South America. The orchids (Orchidaceae) form a family of eight hundred genera and twenty-two to thirty-five thousand species. It is the largest family of the plant kingdom. Orchids are among other things characterized by a two-sided symmetrical flower, which consists of three flower petals and 3 sepals. The middle petal is different in shape and enlarged to a lip.

In addition, all orchids have a symbiotic relationship with fungi, which are called mycorrhiza. Without the presence of these fungi, the seeds of this plant family do not grow into mature plants. The fungi make sure that the orchid can take up minerals. The fungi benefit from this relationship, because they can use the organic substances made by the orchid. We call here of a mutual symbiotic relation, a symbiosis where both organisms benefit. The cooperation with fungi in orchids is very intimate; the hyphae grow through the bark of the roots.

Click on the  thumbnails, when you want to see the large pictures Left: Vanilla planifolia in the educative greenhouse in the Botanical Garden of Amsterdam Right: Vanilla planifolia in a greenhouse in the Botanical Garden of Genève Photo's: Fred Triep

Air Roots

The orchid genus Vanilla contains hundreds of different species, living in tropical and subtropical regions throughout the world. They are epiphytes, which uses trunks as a substrate for their growth. The seeds germinate yet mostly on the ground, whereupon the orchid climbs  along a tree. At a later stage, the contact with the ground disappears because aerial roots take up than water and minerals. The plant has become a true epiphyte. Such an epiphyte is called a hemi-epiphyte.
The flowers appear in spring in a short raceme. The tepals are green to pale yellow in color. The middle petal is shorter and rolled into a cylinder with a wavy margin. The flowers bloom very short, within 24 hours they wither.

Slave

The fruits develop after pollination by the mountain bee (Melipona beechii). Because this bee occur only in the vicinity of the original growth place of V. planifolia, vanilla could not produce in the 17th and the 18th century outside Central America. In 1841 the 12-year-old slave Edmond Albius on Réunion developed a technique, to wipe aside the partition between the stamens and the pistil (the rostellum) with a stick or a beveled bamboo leaves, whereupon the pollination could take place with the thumbs. This technique could from that year the vanilla orchid in other tropical countries used for the production of vanilla. This technique is now also used in the initial growth area of ​​V. planifolia, because the yield through pollination by bees is too low.

Vanilla originate from the unripe fruit of Vanilla planifolia or of the related species V. x tahitensis (a hybrid form in the South Pacific) and V. pompona (West Indies) by fermenting them. After about six months of ripening, the fruits are harvested and the cells of the pods are killed and damaged by cooking, freezing, cutting open or heating in an oven.
The most common method is the Bourbon method of Madagascar and the islands around it, where the fruits are held some time in boiling water. Then the fruits are packed for 7 to 10 days in wool at 45 to 60 degrees Celsius and high humidity. The pods are becoming black during this treatment, while in the pods enzymatic conversions occur by which glucovanillin is converted to glucose and vanillin. The enzymes which are responsible for these conversions, are already found in the fruit, but are normally separated of the glucovanillin. By killing the cells, the enzymes can react with the raw material of vanillin. During the fermentation process many other aromatic substances are created. Hereafter the fruit are dried, to prevent them from rotting and moldy. The fruits are kept in closed boxes between wax paper to preserve the scent.

Handiwork

The word vanilla derives from the Spanish word `vaina`, which means little pod. The Spanish conquistadors led by Cortez gave this name to this product. Vanilla is made from the pod-like fruit of the orchid. The fragrant substance vanillin is made in the fruits at ripening. This organic matter was isolated in 1858 from the fruits. It can also be created artificial from lignin, an organic compound from wood. But the synthesized vanillin lacks the 170 other chemicals that complement  the flavor of vanillin from vanilla.  This artificially created vanillin is used in 95% of the products with vanilla flavor, because natural vanilla is expensive. For the production of vanilla is much handwork required, the flowers must be pollinated manually within twelve hours after the opening and the fruit must be picked at the right time: when they change from green to yellowish green.

There are different types of vanilla on the market, the best known is the Bourbon vanilla, which is produced with V. planifolia in the Indian Ocean (Madagascar, Comoros, Réunion and Indonesia) is produced. The Mexican vanilla comes from the area of ​​origin of this orchid.
Tahitian vanilla comes from French Polynesia and is produced by the species V. tahitensis. In 2008, DNA testing proved, that this plant is a cross between two original Central American species, namely V. planifolia and V. odorata. The West Indian vanilla is produced by V. pompona in the Caribbean. The orchid species V.tahitiensis and V.pompona have a lower yield of vanillin than V. planifolia.

Nowadays most vanilla is produced in countries around the Indian Ocean. The largest producers are Indonesia (60 percent), Madagascar (23 percent) and China (9 percent). Mexico, the area where Cortez and his men ever discovered 'vanilla', provides only 2 percent of this spice.

Coca-cola

Producer soda Coca-Cola is the largest consumer of natural vanilla. When in 1985 the new flavor "New Coke" was introduced the economy of Madagascar collapsed. The reason was that in New Coke the cheaper synthetic substitute vanillin was used. The use of real vanilla drops off during this period by more than a half. The economy of the island again scrambled only after the new Coke was taken out of the assortment due to complaints from consumers.

Plants with leaves and plants without leaves

Most species of the genus Vanilla have leaves. Some species from Africa, Madagascar and Asia have lost their leaves. This is probably an adaptation to dry conditions. The stems have here acquired the primary task of the leaves toward photosynthesis. These plants have often also a groove along the length of the stem, thereby making the stems looking C-shaped in cross-sectional appearance. With this structure the stems can easily shrink under drought conditions, without damage to the cells.

Click on the  thumbnails, when you want to see the large pictures Left: Vanilla madagascariensis in the Tsingy de Bemaraha in Madagaskar Right: Vanilla madagascariensis in the Arboretum d' Antsokay nearToliara (Madagaskar) Photo's: Fred Triep

Vanilla in the Botanical Garden of Amsterdam

The vanilla orchid hangs in the Botanical Gardens of Amsterdam in the educational greenhouse / butterfly house, immediately after entering right behind the two doors. There is also a copy in the tropical part of the “Drie Klimaten Kas” (three climates greenhouse), but this plant is hard to find.

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