Yucca brevifolia

Yucca brevifolia is a monocot in the Lily family.  Joshua Tree got its common name from Mormons, who thought the outstretched branches resembled Joshua in prayer.  It is thought that the Shasta ground sloth was the primary dispersers of the fruits of Joshua Tree before they went extinct.  This species is pollinated by the Yucca moth, which spreads pollen and fertilizes flowers while in the process of laying its eggs inside the flower.  The larvae then hatch in the fruit and feed on the seeds.  So, while the Joshua tree depends on the moth to for reproduction, the moth also can hurt the plant’s ability to reproduce.
Photo Credit: © Nyenyec via Wikimedia Commons
Yucca brevifolia
Common Name: Joshua tree
Other Common Names: Izote de desierto
Plant Functional Group: Evergreen broadleaf
Class > Order > Family: Magnoliopsida > Asparagales > Asparagaceae
What does the species look like?

It is tree-like with a thick trunk and can be up to 40 feet tall. The leaves are evergreen and linear, up to 14 inches long, and taper to a sharp point. The flowers are creamy white, 2.5 inches long, and bell shaped.  They are monoecious, having separate male and female flowers on the same plant. Flowers are found in tight clusters at the end of stalks.

This species is an indicator species of the Mojave desert, found at an elevation between 400 and 1800 meters. It is found on flat areas, mesas, bajadas, and gentle slopes.
Where is the species found?
States & Provinces
AZ, CA, NV, UT
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.
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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.
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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 Yucca brevifolia, the fruit is a spongy capsule that changes from fleshy green to leathery tan, grayish-brown or brown, sometimes the skin cracking to expose the seeds. Do not include empty capsules that have already dropped all of their seeds.
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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 Yucca brevifolia, a fruit is considered ripe when it has turned leathery tan, grayish-brown or brown. Do not include empty capsules that have already dropped all of their seeds.
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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.
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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?

There is currently no photoguide available for this species. If you'd like help us create one, use the guidance document and species template provided here. Then send it via email to education@usanpn.org when it is complete.

USDA PLANTS profile for Joshua tree (USDA Symbol: YUBR )