The genus Agave is treated here in a wide sense to include taxa previously treated as belonging to the genera Manfreda, Prochnyanthes, Polianthes and Pseudobravoa. Not all botanists are happy with this treatment, with some feeling that these genera should remain distinct, at least until further studies have been carried out. In addition, given the high species diversity found in Agave, some feel that an alternative approach could be the recognition of several smaller genera within the current circumscription of Agave[].

Common Name: Agave

General Information

Agave americana is an evergreen, succulent, perennial plant forming a large, rosette of sharply-pointed leaves a metre or more long and a flowering stem that can be 7 metres or more tall.
A true multipurpose plant, providing food, medicine and many commodities for the people who live in its arid environment. It is also used to produce a syrup, which is traded internationally. The plant is often grown as an ornamental.
Agave americana has a relatively wide range, is abundant, the threats affecting it are localised with the exception of extensive ranching that occurs in a wide portion of its range and it occurs in several protected areas. The plant is classified as 'Least Concern' in the IUCN Red List of Threatened Species(2019)[].
Widely cultivated as an ornamental, the plant has escaped from cultivation in some areas - it has become naturalized in the Mediterraneam and is reported as being invasive in New Zealand and some of the Pacific Islands[].

Known Hazards

Contact with the fresh sap can cause dermatitis in sensitive people[, ].
The plants have a very sharp and tough spine at the tip of each leaf. They need to be carefully sited in the garden.
In theory at least, the flowers, nectar, immature flowering stem and the centre of the rosette of all Agave species is edible and, with proper preparation, can provide a sweet, tasty foodstuff. Some species, however, contain relatively high levels of saponins (which makes them taste bitter) and some other compounds which can cause bellyache, and so these would only be eaten in times of desperation. In addition, many people may find these foods to be strongly laxative the first few times they eat them[].

Botanical References

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Range

South-western N. America - Mexico, Texas, Arizona. Naturalized in the Mediterranean[]

Habitat

Original habitat is unknown but it grows wild in Mexico on cultivated land and in pine woods[]. Sandy places in desert scrub at elevations around 200 metres in Texas and eastern Mexico[].

Properties

Weed Potential	Yes
Conservation Status	Least Concern
Edibility Rating
Medicinal Rating
Other Uses Rating
Habit	Evergreen Perennial
Height	7.50 m
Growth Rate	Slow
Pollinators	Lepidoptera, Bats
Cultivation Status	Cultivated, Ornamental, Wild

Cultivation Details

Agave americana is native to semi-arid areas in the warm temperate and subtropical zones, though it has often also been cultivated in the Tropics. It is not very cold hardy, tolerating temperatures down to about -3°c or lower if conditions are not wet[]. We have seen well-sited plants in southwest England that were undamaged by temperatures that fell below -5°c[].
Requires a very well-drained soil and a sunny position[, ]. Succeeds in poor soils[]. Established plants are very drought resistant[].
Agave species are monocarpic, individual plants living for a number of years without flowering then sending up an often very large flowering stem and then dying after flowering and setting seed. The plants of most species, however, normally produce a number of new plants from suckers during their lifespan and these new plants will continue the life-cycle. Over time, some plants can form extensive clonal colonies by this means[].
Individual plants take about 7 - 15 years in their native habitat, considerably longer in colder climates, before flowering[].
Members of this genus are rarely if ever troubled by browsing deer[].

Edible Uses

The heart of the plant is very rich in saccharine matter and can be eaten when baked[, , ]. Sweet and nutritious, but rather fibrous[]. It is partly below ground[].

Seed - ground into a flour and used as a thickener in soups or used with cereal flours when making bread[].

Flower stalk - roasted[, ]. Used like asparagus[].

Sap from the cut flowering stems is used as a syrup[] or fermented into pulque or mescal[]. The sap can also be tapped by boring a hole into the middle of the plant at the base of the flowering stem[].

Medicinal

The sap of agaves has long been used in Central America as a binding agent for various powders used as poultices on wounds[]. The sap can also be taken internally in the treatment of diarrhoea, dysentery etc[].
The sap is antiseptic, diaphoretic, diuretic, emmenagogue and laxative[, , , ]. An infusion of the chopped leaf is purgative and the juice of the leaves is applied to bruises[]. The plant is used internally in the treatment of indigestion, flatulence, constipation, jaundice and dysentery[]. The sap has disinfectant properties and can be taken internally to check the growth of putrefactive bacteria in the stomach and intestines[].

Water in which agave fibre has been soaked for a day can be used as a scalp disinfectant and tonic in cases of falling hair[].

Steroid drug precursors are obtained from the leaves[].

A gum from the root and leaf is used in the treatment of toothache[].

The root is diaphoretic and diuretic[]. It is used in the treatment of syphilis[, ]. The roots are steeped in water, and the water ingested for treating various ailments such as stomach pain, painful and difficult urination, scurvy, swollen and bleeding pulp of teeth, swollen bones, constipation, and poor appetite or loss of appetite[].

All parts of the plant can be harvested for use as required, they can also be dried for later use. The dried leaves and roots store well[].

Agroforestry Uses:

The plants are used in land-reclamation schemes in arid areas of the world[].
The plant is traditionally grown in living fences in the northwestern Himalayas, where it helps to exclude livestock and other animals; mark out land boundaries; whilst also providing a range of medicinal and other uses[].

Other Uses

The plant contains saponins. An extract of the leaves is used as a soap[]. The roots are used according to another report[]. It is likely that the root is the best source of the saponins that are used to make a soap[]. Chop up the leaves or the roots into small pieces and then simmer them in water to extract the saponins. Do not over boil or you will start to break down the saponins[].

There is a report that the plant has insecticidal properties, but further details are not given[, ].

A very strong fibre obtained from the leaves is used for making rope, coarse fabrics etc[, , , ]. A paper can also be made from the leaves[]. The fibre is composed of large filaments, white, brilliant, and readily separated by friction; it takes colour freely and easily; it is light, and contracts under water rapidly[]. Its main faults are the stiffness, shortness, and thinness of wall of the individual fibres, and a liability to rot[].

The thorns on the leaves are used as pins and needles[].

The dried flowering stems are used as a waterproof thatch[] and as a razor strop[].

Propagation

Seed - surface sow in a light position, mid spring in a warm greenhouse. The seed usually germinates in 1 - 3 months at 15 - 20°c[, ]. Prick out the seedlings into individual pots of well-drained soil when they are large enough to handle and grow them on in a sunny position in the greenhouse until they are at least 15cm tall. Plant out at the beginning of the growing season, and give some protection from the cold for at least their first few winters[].
Offsets and suckers can be potted up at any time they are available. Keep in a warm greenhouse until they are well established[].
Bulbils, where produced, are an easy method of propagation. Simply pot them up and plant out at the beginning of a growing season when they are 10cm or more tall.