Photo Credit: John Ruter, University of Georgia, Bugwood.org. Creative Commons Attribution-Noncommercial 3.0 United States (CC BY-NC 3.0 US) License; https://creativecommons.org/licenses/by-nc/3.0/us/.
Agave americana
Common Name: American century plant
Other Common Names: American agave, centuryplant, maguey americano
Plant Functional Group: Evergreen broadleaf
Class > Order > Family: Magnoliopsida > Asparagales > Asparagaceae
Where is the species found?
States & Provinces
AZ, CA, FL, HI, LA, TX, VI
Which phenophases should I observe?
Do you see...?
Flowers Flowers or flower buds
One or more fresh open or unopened flowers or flower buds are visible on the plant. Include flower buds or inflorescences that are swelling or expanding, but do not include those that are tightly closed and not actively growing (dormant). Also do not include wilted or dried flowers.
More...

How many flowers and flower buds are present? For species in which individual flowers are clustered in flower heads, spikes or catkins (inflorescences), simply estimate the number of flower heads, spikes or catkins and not the number of individual flowers.

  • Less than 3
  • 3 to 10
  • 11 to 100
  • 101 to 1,000
  • 1,001 to 10,000
  • More than 10,000

Open flowers
One or more open, fresh flowers are visible on the plant. Flowers are considered "open" when the reproductive parts (male stamens or female pistils) are visible between or within unfolded or open flower parts (petals, floral tubes or sepals). Do not include wilted or dried flowers.
More...

What percentage of all fresh flowers (buds plus unopened plus open) on the plant are open? For species in which individual flowers are clustered in flower heads, spikes or catkins (inflorescences), estimate the percentage of all individual flowers that are open.

  • Less than 5%
  • 5-24%
  • 25-49%
  • 50-74%
  • 75-94%
  • 95% or more

Fruits Fruits
One or more fruits are visible on the plant. For Agave americana, the fruit is a capsule that changes from green to brown or blackish and splits open to expose the seeds. Do not include empty capsules that have already dropped all of their seeds.
More...

How many fruits are present?

  • Less than 3
  • 3 to 10
  • 11 to 100
  • 101 to 1,000
  • 1,001 to 10,000
  • More than 10,000

Ripe fruits
One or more ripe fruits are visible on the plant. For Agave americana, a fruit is considered ripe when it has turned brown or blackish and has split open to expose the seeds. Do not include empty capsules that have already dropped all of their seeds.
More...

What percentage of all fruits (unripe plus ripe) on the plant are ripe?

  • Less than 5%
  • 5-24%
  • 25-49%
  • 50-74%
  • 75-94%
  • 95% or more

Recent fruit or seed drop
One or more mature fruits or seeds have dropped or been removed from the plant since your last visit. Do not include obviously immature fruits that have dropped before ripening, such as in a heavy rain or wind, or empty fruits that had long ago dropped all of their seeds but remained on the plant.
More...

How many mature fruits have dropped seeds or have completely dropped or been removed from the plant since your last visit?

  • Less than 3
  • 3 to 10
  • 11 to 100
  • 101 to 1,000
  • 1,001 to 10,000
  • More than 10,000

What do these phenophases look like?

The following Phenophase Photo Guides for this species have been vetted for accuracy by the USA-NPN National Coordinating Office. Most photo guides are developed for a particular local or regional monitoring effort, and some of the content may not apply to your effort or your region. However, we make them available to provide as much help as they may in illustrating phenophases for this species. If you have high quality phenophase photos that you are willing to share with us, please visit the Phenophase Photo Guidelines page.

Be aware there is variation from individual to individual within a species, especially across different regions, so your plant may not look exactly like the one pictured.

Since they do not always include complete definitions for the species, use these photo guides ONLY in conjunction with the official Nature's Notebook phenophase defintions included in the table above, in the phenophase definition sheet that downloads with the datasheet, or in the Observe screen in the mobile app.