Agave americana

American aloe


Agave americana

L. 1753

pronounced: uh-GAH-vee uh-meh-rick-AH-nuh

(Asparagaceae — the asparagus family)

common names: American aloe, century plant, maguey

Agave is from the Greek αγαυος (agauos), noble, handsome; americana is, as you would expect, botanical Latin for ‘of America’. The common name of Century Plant, shared with Agave desmettiana, is used because the plants take a long time to bloom – not a whole century, but usually about 10 years in tropical climates, and around 60 years in colder climates.

The plant is originally from Mexico, but cultivated worldwide as an ornamental plant. It has since naturalized in many regions, and grows wild in southern Europe, southern China, southern Africa, India, New Zealand and Australia. One of he plants photographed grows on the rocky slopes at the southern end of Geoffrey Bay, and the other on Nobby Head, Picnic Bay.

The plant is a rosette that can grow up to about 4 m in diameter, of grey-green leaves 1 - 2 m long and 15 - 25 cm wide, with spiny margins, the spines recurved like fishhooks, and a heavy dark brown spike, up to 2.5 cm long, at the tip. This is very sharp, and dangerous if encountered. The leaves are lanceolate and may be upright or spreading in nature, and are sometimes bent backwards near their tips. They are usually rigid and somewhat fleshy, and normally bluish grey to greyish green in colour, but there are forms with variegated leaves.

The massive flower clusters are borne at the top of a very robust flowering stem. The clusters are much-branched, with the branches being further divided towards their tips – they are terminal panicles. The individual flowers are borne in an erect position on pedicels 2 - 4 cm long. The flowers, each about 7 - 10 cm long, are yellow or greenish yellow with their 6 tepals fused together at the base into a short tube. The flowers also have 6 very prominent stamens, consisting of filaments 6 - 10 cm long and yellow anthers about 3 cm long. The ovary is large, and topped with a style and 3 stigmas.

The fruit are large oblong capsules (about 4 - 8 cm) with a beaked apex, and have 3 compartments. The capsules turn from green to brown or blackish in colour as they mature, and eventually split open to release their seeds. These seeds are 6 - 8 mm long, black and shiny.

The flower spike can reach up to about 8 m in height. The ones pictured look very spectacular against the background of the ocean. The plant dies after flowering, but produces adventitious shoots from the base, and these continue the lineage. Seeds also contribute, and are dispersed by both wind and water.

Agave americana is regarded as en environmental weed in several parts of the world. The prickles on the leaf margins and the spines at the tips of the leaves can cause injury to people and to both domestic and native animals. Large clumps can have an impact on pastures, preventing the growth of more suitable species, and restricting the access of livestock.

The only woody material produced by this plant is the flower spike. An Australian craftsman, Rob Day, has found a use for this wood in the making of didgeridoos. The traditional method of didgeridoo making is to find a natural hollow log, usually of a eucalyptus species, that has been eaten out by termites, and that also plays a decent musical key. Owing to the enormous popularity of didgeridoos with overseas backpackers (most of whom take one home as a souvenir of Australia) there is now a shortage of traditional materials, and Rob is using dried and hollowed-out stems of the Agave americana as a substitute material.

Photographs taken in Geoffrey Bay 2013, Picnic Bay 2015
Page last updated 1st October 2018