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:

General Information

Agave shawii is an evergreen, succulent plant developing a central erect to decumbent, branched stem that can reach up to 200cm long, atop of which is a rosette of leaves that can be 80 - 200cm tall and 100 - 250cm in diameter. The leaves on mature plants can each be 20 - 50cm long and 8 - 20cm wide near the base. After several years of growth, a flowering stem that can be around 2 - 4 metres tall is produced, after which the rosette will die. The plant will often produce new rosettes from branches along the stem and these continue to grow[, , ].
The plant is sometimes harvested from the wild for local use as a food, drink and source of fibres. The fibres have been used in the past on a commercial basis, but they are considered to be short and of poor quality[]. The plant is sometimes grown as an ornamental[].
Agave shawii was abundant in southern California at the beginning of the twentieth century. Since then, unrestricted collecting and habitat destruction have reduced the populations significantly[]. The plant is facing threats across its range and although the northern subspecies, A. shawii ssp. shawii, is facing significant declines, the decline of the species as a whole is currently not occurring at a rate to trigger a red listing. The plant is classified as 'Least Concern' in the IUCN Red List of Threatened Species(2019)[].

Known Hazards

Many Agave species have strong, sharp spines on the leaves and leaf tips.
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

Range

Southwestern N. America - southern California, northern Baja California Norte

Habitat

A mainly coastal species, found in succulent maritime scrub and central desert, and a frequent component of the coastal sagebrush community[, ].

Properties

Conservation Status	Least Concern
Edibility Rating
Other Uses Rating
Habit	Evergreen Tree
Height	2.00 m
Pollinators	Bats, Hummingbirds, Bees
Cultivation Status	Ornamental, Wild

Cultivation Details

Agave shawii is native to the Mediterranean climate of coastal California and Baja California with hot, dry summers and rainfall occurring in winter and early spring. Rainfall here can be as low as 85 - 95mm a year, but this is considerably ameliorated by the frequent fogs that condense and bathe the leaves whilst also reducing insolation and temperatures[].
Agave species generally require a sunny position, succeeding in most soils of medium-fertility so long as they are very well-drained. Most species are undemanding as to the soil pH, though those found in the wild on limestone soils will grow better in neutral to alkaline conditions. Plants are generally very tolerant of dry conditions and of drought[].
Agave species are mainly monocarpic, individual rosettes living for a number of years without flowering before sending up an often very large flowering stem and then dying after flowering and setting seed. This species, however, often branches from the leaf axils to form new rosettes and these will continue the life-cycle after the original rosette has flowered and died[]
Individual plants can take about 20 - 40 years in their native habitat, considerably longer in colder climates, before flowering[].

Edible Uses

Flowers - cooked[].

The meristem has been eaten[]. This probably refers to the central portion of the rosette[].

The plant is used to make 'mezcal'[]. Mezcal is a distilled alcoholic beverage that potentially can be made from almost any species of Agave, though only around fifty are used regularly and seven species are especially favoured. Mature plants are harvested from the wild, their leaves and roots are removed and the remaining 'hearts' are baked (often in an earth oven), then mashed and the resulting liquid allowed to ferment for a few days before being distilled to produce mezcal.

Medicinal

None known

Other Uses

Fibres can be obtained from the leaves[, ]. Coarse, they are used for cordage.

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.