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: Century Plant

General Information

Agave utahensis is an evergreen, stemless, succulent plant forming a compact rosette of leaves that can be 15 - 60cm tall and 25 - 100cm in diameter. Around 70 - 80 leaves are produced on mature plants, each of which can be 15 - 50cm long and 2 - 3cm wide near the base. After several years of growth, a flowering stem that can be around 170 - 400cm tall is produced, after which the rosette will die. However, the plant usually produces a number of young plants around its base that will develop as new plants[].
The plant was very important for the native north Americans, providing them with food, medicines and a range of materials. It is much less used at the present time. The plant is often grown as an ornamental , especially in xeriscape gardens.
Agave utahensis has a relatively large range, stable overall populations and, even though it is affected by threats in part of its range, it occurs in sevaral protected areas. The plant is classified as 'Least Concern' in the IUCN Red List of Threatened Species(2020)[]. Although generally considered least concern, it should be noted that illegal
collection of the variety Agave utahensis eborispina for ornamental use has resulted in high levels of removal of mature individuals of this portion of the population[].

Known Hazards

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 - California, Nevada, Utah, Arizona

Habitat

Dry stony limestone slopes, at elevations from 600 - 2,280 metres[, ].
Calcareous or sandstone outcrops in desert scrub, pinyon-juniper, or conifer woodlands; at elevations from 700 - 2,500 metres[].

Properties

Conservation Status	Least Concern
Edibility Rating
Medicinal Rating
Other Uses Rating
Habit	Evergreen Perennial
Height	2.00 m
Pollinators	Moths, Bats
Cultivation Status	Ornamental, Wild

Cultivation Details

Agave utahensis is a native of arid and semi-arid climates. Plants are only hardy in the milder areas of the temperate zone, and even then need to be sited carefully to prevent rot from excessive moisture. They generally grow well in Mediterranean climates. Plants from northern and/or high elevation populations of ssp. utahensis, ssp. kaibabensis and var. eborispina may tolerate temperatures down to between -21 to -29°c, and may survive outdoors in central Europe nearly without rain protection[]. Plants also experience snow in their native environment, though this can have the effect of insulating their base and roots from the cold[].
Requires a very well-drained soil and a sunny position[, ].
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[].
This plant is widely used by the native people in its wild habitat, it has a wide range of uses.
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 delicious, but rather fibrous[]. It is partly below ground. It can be dried for future use or soaked in water to produce a flavourful beverage[].

Seed - ground into a flour[, ].

Flower stalk - roasted[].

Root - cooked[].

Sap from the cut flowering stems is used as a syrup[]. The sap can also be tapped by boring a hole into the middle of the plant at the base of the flowering stem[]. It can be fermented into 'Mezcal', a very potent alcoholic drink[]. Mezcal is a distilled drink, made from the baked hearts of the agave plant. The fermented sap mentioned above is more commonly called 'pulque' in Mexico, where it is commonly produced from a number of Agave species and has a much lower alcohol content[].

Medicinal

The sap is antiseptic, diuretic and laxative[].

The plant contains steroidal saponins which are under research for use in the treatment of certain cancers[].

Other Uses

The leaves contain saponins and an extract of them can be used as a soap[]. It is best obtained by chopping up the leaves and then simmering them in water - do not boil for too long or this will start to break down the saponins[].

A very strong fibre obtained from the leaves is used for making rope, coarse fabrics etc[, , ].
To make hair brushes and brushes for cleaning, the dried matter of a dead and rotten leaf was knocked free from the fibres, which were then bent in two. the upper end of this brush was wrapped with a cord and the bent portion was covered with a cloth. The loose fibres were cut to the right length and hardened by burning the ends[].
A paper can also be made from the fibre in the leaves[].

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.