The Mexican coriander is a perennial herb from the parsley family (Apiaceae) that grows in tropical climates. Its scientific name is Eryngium foetidum, which can be directly translated as "thistle with bad smell". The popular name comes from its native location, since the plant's origin is in Mexico and some parts of South America. It is now cultivated all over the world, including in temperate areas where it has become adapted to an annual life cycle. Despite being very popular in Mexico, this herb is relatively unknown in the USA, where only the Latino, Hispanic, Caribbean and Indo-Caribbean communities use it. It is popularly known as culantro in the USA, which can be confused with cilantro, a term that actually designates the leaves of a different plant, Coriandrum sativum. However, the two species are related and part of the Apiaceae family, just that the cilantro has a weaker taste.
The Mexican coriander is an herb with thorns that can reach a height of 30 cm. Mexican coriander grows from a stout taproot and is a tough flowering species with multiple branches, which has a strong coriander smell. Leaves have a length of 10 to 16 cm, with a width between 3 and 4 cm and mostly grow in a rosette at the base. They are narrow, with rounded tips and a tapered base and their edges are jagged and spiny. Stem leaves grow in opposite pairs and are much smaller, only about 2 to 3 cm long and 0.5 to 1.5 cm wide. They usually consist of 3 parts and also have thorny teeth on their sides. The small flowers are located on top of a larger ring of spines and have a pale green color. They have a length of about 1 cm, with a conical shape.
Leaves, buds, young shoots.
It has been known for a long time that the Mexican coriander has strong medical properties. It is said to be especially beneficial for the digestive system, while boosting appetite at the same time. The powerful mix of nutrients in the herb increases human immunity, preventing many diseases.
The Mexican coriander leaves are often used to brew an herbal tea, which is known as a treatment against fevers, pneumonia, diarrhea or flu. When prepared as a decoction, the leaves act as a painkiller and can reduce inflammation. Some studies have been performed on the plant's essential oil, which can kill various pathogens including fungi, nematodes, trypanosomes and bacteria.
Leaves are also potent against intestinal disorders, such as constipation, internal parasites or stomach pain. Eating the roots is an ancient counter for scorpion stings, while several parts of the herb can treat epilepsy.
The Mexican coriander has a long history of use in herbal medicine. It has been employed as a cure against infectious and digestive diseases like fever, vomiting or diarrhea. To use as a treatment for malaria, flu, pneumonia or diabetes, the Mexican coriander roots have to be boiled then discarded, using just the remaining water.
In Venezuela, decoctions of the root are known to have several powerful medical properties, acting as an abortive, sedative, stimulant and antipyretic. Cubans praise it as an emmenagogue. Mexican coriander is known to reduce high blood pressure and prevent seizures across all tropical zones of the Americas. The roots and seeds can cure ear pain, leaf infusions reduce stomach ache, while colic can be treated by infusing the plant with salt.
The herb's effects against diarrhea in children are used in a particular way by the Chamis Indians, who make them inhale the smoke after drying and braising the fruits. The unripe fruits are also said to combat insomnia, when added in food. In Creole medicine, Mexican coriander leaves are crushed and rubbed on the body in order to reduce fever, while herb's decoctions are a remedy against flu.
Some parts of the herb have been investigated by modern scientists, with interesting results. Hot aqueous extracts were found to be anticonvulsants, while ethanolic extracts from the aerial parts have cardiovascular, diuretic and antistrychnine properties. The root is especially potent against infections of the urinary tract such as urethritis, cystitis, polyuria, prostate problems or renal colic, but can also reduce inflammation and act as a diuretic.
Pressing the leaves produces a juice that relieves stomach pain, while the raw leaves themselves can help with female issues, reducing the duration of labor, removing the placenta and calming menstrual pains. The Mexican coriander can counter allergies, malaria and insect bites, and it also acts as a general laxative and purgative that eliminates toxins from the body.
Decoctions of the herb have various uses in the treatment of children, curing simple diseases such as the flu or complex ones like epilepsy. Rubbing the herb on the body can be a simple but very effective cure for convulsions and fainting. In Jamaica it has been used for a long time to treat hysterical and fainting people due to the very strong belief that the herb has magic powers and can offer protection against ghosts. In African medicine, Mexican coriander is mainly considered a cure against headache and stomach pain. Tests have shown that the Mexican coriander root has a content of saponin and about 0.02-0.04% essential oils.
Besides its medical benefits, Mexican coriander is an important spice and flavouring agent in food. It is widely used in the cuisine of the Caribbean in chutneys and other recipes, as well as in some parts of Asia.
Leaves have the strongest flavour and can be added after chopping in fish dishes, as well as soups, salads, sauces, vegetables, dips or curries.
Outside the Caribbean Islands, the Mexican coriander is very popular in Central and South America in countries like Panama and the Amazonian areas of Peru as a seasoning and garnishing ingredient. India, Thailand, Vietnam and Laos are the Asian countries were the Mexican coriander is widely eaten. It is very useful in the herbal and spice industry because it retains both its taste and its color after drying. It can replace normal coriander in any recipe but it has a much stronger taste.
The Mexican coriander can be found in US grocery stores where it is usually named culantro and often confused with the cilantro. It grows in the wild in Hawaii, Puerto Rico and the Virgin Islands, as well as the states of Georgia and Florida.
The plants tend to die after they produce seeds, even if new ones can be self-seeded in the same location. To prevent this and harvest the leaves as long as possible, you can constantly cut off the flower stalks to prevent them from blooming. Viable seeds germinate after 3 or 4 weeks. Since the Mexican coriander is small in size, it can be cultivated in indoor pots.
For best results, choose moist sandy loam with good drainage. When planted in sunny locations, the bloom can be very fast, which usually ends the life cycle of the plant. This is why it is usually cultivated in partial or even total shade, where it can be harvested for longer.
The Mexican coriander likes both tropical and sub-tropical climates but too much heat will kill it. It has been adapted in temperate areas but can't tolerate frost at all. The soil must have good drainage because it needs constant watering in order to grow well.
Modern research on leaves of the Mexican coriander has revealed a high concentration of aliphatic aldehydes, most of the α,β unsaturated variety. The most important of these compounds, about 60% of total, is E-2-dodecenal. Others have also been found in smaller amounts: 2,3,6-trimethylbenzaldehyde (10%), dodecanal (7%) and E-2-tridecenal (5%). These chemicals cause the very specific coriander aroma and they are found in other plants that share it.
No aldehydes have been identified in the essential oil in the seeds. However, other compounds such as phenyl-propanoids (anethole), monoterpenes (α-pinene) and sesquiterpenoids (carotol 20%, β-farnesene 10%) have been detected.