Agave americana
(century plant)

Preferred Common Name

• century plant

Other Scientific Names

• Agave altissima Zumagl.
• Agave communis Gaterau
• Agave complicata Trel. ex Ochot.
• Agave cordillerensis Lodé & Pino
• Agave felina Trel.
• Agave fuerstenbergii Jacobi
• Agave gracilispina (Rol.-Goss.) Engelm. ex Trel.
• Agave ingens A.Berger
• Agave melliflua Trel.
• Agave milleri Haw.
• Agave ornata Jacobi
• Agave picta Salm-Dyck
• Agave rasconensis Trel.
• Agave subtilis Trel.
• Agave subzonata Trel.
• Agave theometel Zuccagni
• Agave zonata Trel.
• Aloe americana (L.) Crantz

International Common Names

• English: agave; American agave; American aloe
• Spanish: cabuya (Bolivia); henequen; maguey; penca; pita; pita comun
• French: agave américain; agave d'Amérique; choca; faux aloès; pite
• Chinese: long she lan
• Portuguese: piteira; piteira-brava; piteira-de-boi

Local Common Names

• Brazil: caroata-acu
• Ecuador/Galapagos Islands: Cubuya negra; penco
• Germany: Agave, Amerikanische; Agave, hundertjährige
• Greece: alades; alas; lalas
• Italy: pitta; zabbara; zammara
• Portugal: aloé-dos-cem-anos ; pita; piteira; piteira-brava; piteira-de-boi
• South Africa: garingboom; spreading century plant
• Spain: agave americano; aloe americano; azabara; maguey Americano; pita; pitaco; pitera

EPPO code

• AGVAM (Agave americana)

• Domain: Eukaryota
•     Kingdom: Plantae
•         Phylum: Spermatophyta
•             Subphylum: Angiospermae
•                 Class: Monocotyledonae
•                     Order: Liliales
•                         Family: Agavaceae
•                             Genus: Agave
•                                 Species: Agave americana

The family Asparagales includes about 153 genera and 2500 species that are distributed worldwide. This family is subdivided into seven subfamilies: Aphyllanthoideae, Agavoideae, Brodiaeoideae, Scilloideae, Lomandroideae, Asparagoideae, and Nolinoideae. For some authors, the classification of this family is highly unsatisfactory. There are no specific traits that characterize this family, some of the subfamilies are difficult to recognize while others are very distinctive. Flowers for the most part are a rather undistinguished "lily"-type.

The subfamily Agavoideae, that comprises the genera Agave and Yucca, has been classified previously as a separate family, Agavaceae. The genus Agave includes about 220 species widespread in the tropical and subtropical regions of the world mainly in desert, dry and semiarid environments (Stevens, 2012). A. americana is a highly variable species, thus many “forms” have been treated as species, subspecies, and varieties (The Plant List, 2013).

A. americana was originally described by Linnaeus as one of the four members which he included in the genus Agave L. A. americana is the type species (generitype) of the genus Agave (Hitchcock, 1929). Two subspecies are widely recognized, A americana subsp. protamericana Gentry, and A. americana subsp. americana var. expansa (Jacobi) Gentry (Reveal and Hodgson, 2002). Although the species is given the common name century plant, derived from the long time it takes to flower, it typically only lives 10-30 years.

Plants acaulescent or short-stemmed, commonly suckering, trunks less than 2 m; rosettes not cespitose, 10–20 × 20-37 dm. Leaves erect, spreading to ascending, occasionally reflexed, 80–200 × 15-25 cm; blade light green to green or glaucous-gray, sometimes variegated or cross-zoned, narrowly to broadly lanceolate, smooth, rigid; margins nearly straight or undulate to crenate, armed, teeth single, 5-10 mm, 1-4 cm apart; apical spine dark brown to grayish, conical or subulate, 2-6 cm. Scape 5-9 m. Inflorescences paniculate, not bulbiferous; bracts persistent, triangular, 5-15 cm; lateral branches 15-35, horizontal to slightly ascending, comprising distal 1/3-1/2 of inflorescence, longer than 10 cm. Flowers erect, 7-10.5 cm; perianth yellow, tube funnelform to cylindric, 8-20 × 12-20 mm, limb lobes erect, subequal, 20-35 mm; stamens long-exserted; filaments inserted above mid perianth tube, erect, yellow, 6-9 cm; anthers yellow, 25-35 mm; ovary 3-4.5 cm, neck constricted, 3-6(-8) mm. Capsules short-pedicellate, oblong, 3.5-8 cm, apex beaked. Seeds 6-8 mm (Flora of North America Editorial Committee, 2016).

A. americana has been widely introduced throughout the world for its ornamental value. However, because it is very difficult to collect, herbarium records probably greatly underestimate the actual distribution of this species in areas outside its native distribution range (PROTA, 2016; USDA-ARS, 2016; Weeds of Australia, 2016). It is believed that A. americana arrived in Europe around 1520, and the first description of this species in Europe was made by J.A. Cortoses in 1561, growing at Padua in northern Italy (Sydow, 1987).

On the Canary Islands, A. americana was introduced from Central America probably during the sixteenth century, and it is now widespread on most of the islands (Rodríguez et al., 2015). In continental Spain, several species of Agave, including A. americana were introduced in the 1940s as ornamental and cultivated plants, and now these species are spreading into new habitats, mainly on coastal sandy soils (Badano and Pugnaire, 2004).

In South Africa the plant was introduced in the 1960s and now it is spreading across the Western Cape, Eastern Cape, KwaZulu-Natal, Free State, Northern Cape, Limpopo, and Mpumalanga and is listed as invasive within the Kruger National Park (Invasive Species South Africa, 2016).

A. americana is widely cultivated and can be found naturalized and spreading in many parts of Australia including Queensland, Western Australia, New South Wales, Victoria and south-eastern South Australia. It is also naturalized on Lord Howe Island and Norfolk Island (Weeds of Australia, 2016).

In Puerto Rico and the Virgin Islands, A. americana is cultivated as an ornamental, but apparently is not yet naturalized (Acevedo-Rodríguez and Strong, 2005).

Soil drainage

• free

Soil reaction

• acid
• neutral

Soil texture

• light
• medium

Special soil tolerances

• infertile

A. americana spreads by seeds, which can be dispersed by both wind and water, and vegetatively via rhizomes and suckers. Daughter plants, seeds and stem fragments are carried to new sites by ocean tides, by deliberate plantings, soil movement especially down banks, dumped vegetation, and naturally as garden escapes (ISSG, 2016; Weeds of Australia, 2016, Weeds of New Zealand, 2016). Plants are most commonly spread into bushland areas in dumped garden waste (BioNET-EAFRINET, 2016).

The prickles along the leaf margins and sharp spines on the tips of the leaves can cause injury to people and animals (both domestic livestock and native animals). Large clumps can have an impact on pastures, as these dense colonies can prevent the growth of more suitable species and restrict the access of livestock (BioNET-EAFRINET, 2016; ISSG, 2016; Weeds of New Zealand, 2016).

A. americana is regarded as an environmental weed and invasive species in many countries in Europe as well as in China, Japan, South Africa, Namibia, Tanzania, Bermuda, Australia, New Zealand, and New Caledonia (BioNET-EAFRINET, 2016; ISSG, 2016; DAISIE, 2016; PIER, 2016; Weeds of Australia, 2016). The species grows forming dense almost impenetrable thickets that displace native vegetation and inhibit the movement of native fauna (ISSG, 2016). One of the major impacts of A. americana is its large leaves shading out native plant species. It also has a very dense network of rhizome offshoots, which could draw resources away from native species. The rhizomatous nature of A. americana could also alter the nutrient status of the soil (ISSG, 2016).

Impact on Habitats

In New Zealand, A. americana is replacing vulnerable dune species. It also colonizes bare sand, causing build-ups of sand which can lead to new (usually exotic) habitats being formed and erosion elsewhere (Weeds of New Zealand, 2016). In South Africa, it is considered a noxious invasive weed and grows forming dense, almost impenetrable thickets that can cause injury to people and animals (Invasive Species South Africa, 2016). In Australia, A. americana is regarded as an environmental weed in Victoria, New South Wales, South Australia, Western Australia and Queensland, and is thought to pose a significant threat to rangeland biodiversity in Australia. Though this species grows and spreads slowly, and is largely seen as an invader of roadsides and disturbed sites, it is also found growing in natural vegetation and eventually forms dense almost impenetrable thickets (Weeds of Australia, 2016).

In coastal dune habitats in southern Spain, A. americana is one of the invasive plants listed as increasing in number and affecting the conservation of natural coastal ecosystems.

Impact on Biodiversity

On the island of Malta, A. americana is outcompeting and replacing critically endangered Cheirolophus crassifolius (the national plant of Malta) and the endangered Atriplex lanfancoi (formerly Cremnophyton lanfrancoi) (ISSG, 2016). On the Canary Islands, A. americana is an aggressive invader threatening species listed as critically endangered, endangered and vulnerable such as Crambe wildpretii, Crambe pritzelii and Asparagus arborescens (Arévalo et al. 2005; ISSG, 2016). On Tenerife in the Canary Islands, the native bird community uses A. americana as a feeding resource at a higher rate than it uses endemic plants, which could have positive effects on birds but negative impact on the pollination of invasive plants (Rodríguez et al., 2015).

• Proved invasive outside its native range
• Has a broad native range
• Abundant in its native range
• Highly adaptable to different environments
• Is a habitat generalist
• Tolerates, or benefits from, cultivation, browsing pressure, mutilation, fire etc
• Pioneering in disturbed areas
• Highly mobile locally
• Benefits from human association (i.e. it is a human commensal)
• Long lived
• Gregarious
• Reproduces asexually

• Damaged ecosystem services
• Ecosystem change/ habitat alteration
• Modification of hydrology
• Modification of successional patterns
• Monoculture formation
• Reduced amenity values
• Reduced native biodiversity
• Soil accretion
• Threat to/ loss of endangered species
• Threat to/ loss of native species

• Causes allergic responses
• Competition - monopolizing resources
• Competition - smothering
• Poisoning
• Rooting
• Produces spines, thorns or burrs

• Highly likely to be transported internationally deliberately
• Difficult/costly to control

Economic Value

A. americana has been widely commercialized for its ornamental value. This species is grown as an ornamental and hedge plant on all continents, except Antarctica (Nobel, 1988; USDA-ARS, 2016). A. americana is also used as a fodder, although it cannot be directly grazed and requires processing before feeding. The leaf fibres are sometimes used to make textiles (PROTA, 2016; USDA-ARS, 2016).

Social Benefit

In Mexico and South Africa, A. americana is used to brew an alcoholic liquor beverage (PROTA, 2016). It is also used in traditional medicine to treat to treat cardiac problems, high blood pressure, gastro-intestinal problems and rheumatic pain (PROTA, 2016; USDA-ARS, 2016).

Environmental Services

A. americana is used a hedge plant and planted along contours for erosion control and for reclamation of denuded and overgrazed land. (USDA-ARS, 2016).