agave; maguey
General term for plants of the genus Agave, often used for species like Agave americana. In everyday Japanese, リュウゼツラン is the standard name.
The agave blooms only once every few decades.
century plant; American aloe
Specifically Agave americana, a large succulent known for its long life and dramatic flowering stalk. Often called アメリカリュウゼツラン in botanical contexts.
この植物園には巨大なリュウゼツラン（アメリカリュウゼツラン）がある。
This botanical garden has a huge century plant (Agave americana).