Carnegiea gigantea

Saguaro is the largest of the columnar cacti found in the United States.
Photo Credit: © USDA-NRCS PLANTS Database.
Carnegiea gigantea
Common Name: saguaro
Other Scientific Names: Carnegia gigantea
Plant Functional Group: Cactus
Class > Order > Family: Magnoliopsida > Caryophyllales > Cactaceae
What does the species look like?

Saguaro is large, spiny, stem succulent growing up to 52 feet tall or more, acquiring branches with age. Its showy, white and yellow flowers have both male and female parts, and are insect- and animal-pollinated. Flowering begins when the plant becomes mature at about 7 feet tall.

Saguaro is found in the Sonoran Desert of the southwestern U.S., from the valley bottoms and up on steep, rocky, slopes. It is found on shallow soils that are light, coarse-textured, and rocky. It is intolerant of cold.
Where is the species found?
States & Provinces
AZ, CA
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
  • More than 1,000
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 Carnegiea gigantea, the fruit is a fleshy, juicy, very large berry that changes from green to yellow-green, reddish-green or red and splits open to expose red pulp filled with seeds. Do not include empty fruits that no longer have any red pulp or seeds.
More...

How many fruits are present?

  • Less than 3
  • 3 to 10
  • 11 to 100
  • 101 to 1,000
  • More than 1,000
Ripe fruits
One or more ripe fruits are visible on the plant. For Carnegiea gigantea, a fruit is considered ripe when it has turned yellow-green, reddish-green or red and has split open to expose red pulp filled with seeds. Do not include empty fruits that no longer have any red pulp or 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
  • More than 1,000
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.

ITIS information for saguaro (ITIS TSN: 506151 )
USDA PLANTS profile for saguaro (USDA Symbol: CAGI10 )