Agave
Agaves originate in the dry arid regions of the southern USA, Mexico and central America. They arrived in Europe in the 16th century, hence the agave is a very early example of 'designer garden plants'.
The stem is usually very short, and can appear non-existent. The leaves are quite long and fleshy and have a sharp point on the end. Sometimes there are further spines along the edges of the leaves. variegated varieties are also common, with a cream stripe either along the middle of the leaf or along the two edges.
The agave plant flowers just once then dies, but it can take several decades for this flowering to arrive.
The easiest form of propagation is with the small plants that grow as suckers from the main plant.
The plant is reasonably hardy but is best protected from frosts in colder climates.

