"the aloe that flowers once in a hundred years"
Agave americana
GNU Free Documentation LicenseAgave americana - Credit: Digigalos, Wikimedia Commons
The true Aloe (Aloe Perryi or Aloe vera) flowers throughout
Aloe vera
GNU Free Documentation LicenseAloe vera - Credit: Sten Porse, Wikimedia Commons
most of the year. It is another variety of Aloe, the American Aloe (Agave americana), which is noted for the infrequency of its flowering.