Purshia tridentata

antelope bitterbrush
Photo for species Purshia tridentata
Did you know?: 

Purshia tridentata is a high-quality, palatable shrub that is very important to wildlife and browsed by livestock. It provides cover for many animals and birds, and is used in reclaiming mining sites. Native Americans used the outer seed coats to make a purple stain for wood; they also used the plant medicinally.

Photo Credit: 
© R.A. Howard, Courtesy of Smithsonian Institution, Dept. of Systematic Biology, Botany.
What does this species look like?

Antelope bitterbrush is a single- to many-stemmed, intricately branched, late-deciduous to evergreen shrub growing 2 to 16 feet tall. The small, showy, white, cream, or yellow flowers have both male and female parts and are arranged along the branches. Flowering begins after plants reach maturity at about 8-10 years of age. Flowers are insect- and wind- pollinated.

Although antelope bitterbrush grows best on deep, well-drained, gravelly, loamy, course sands and rocky soils, it is also adapted to a wide range of soil types. Typical habitats include dry lake beds, plains, foothills, alluvial fans or terraces, mountain slopes, mesas, and open woodlands. It is found in sagebrush, chaparral, mountain brush, pinyon-juniper, and ponderosa pine communities. It is drought-tolerant but shade intolerant.

Why observe this species?

Antelope bitterbrush is a USA-NPN regional plant species. Regional species are ecologically or economically important and are distributed more locally than calibration species. The NPN integrates these observations to better understand plant responses within the different geographic regions of the nation.

Where is this species found?
U.S. States: 
AZ, CA, CO, ID, MT, NE, NM, NV, OR, UT, WA, WY
Which phenophases should I observe?
Leaves

Do you see...?

Breaking leaf buds
One or more breaking leaf buds are visible on the plant. A leaf bud is considered "breaking" once a green leaf tip is visible at the end of the bud, but before the first leaf from the bud has unfolded to expose the leaf stalk (petiole) or leaf base.

How many buds are breaking?

Less than 3

3 to 10

More than 10

More...

Leaves
One or more live unfolded leaves are visible on the plant. A leaf is considered "unfolded" once the leaf stalk (petiole) or leaf base is visible. New small leaves may need to be bent backwards to see whether the leaf stalk or leaf base is visible. Do not include dried or dead leaves.

What proportion of the canopy is full with leaves?

Less than 5%

5-24%

25-49%

50-74%

75-94%

95% or more

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Increasing leaf size
A majority of leaves on the plant have not yet reached their full size and are still growing larger. Do not include new leaves that continue to emerge at the ends of elongating stems throughout the growing season.

What proportion of full size are most leaves?

Less than 25%

25-49%

50-74%

75-94%

95% or more

More...

Flowers

Do you see...?

Flowers
One or more fresh flowers or flower heads (inflorescences) are visible on the plant. Flower heads include many small flowers that usually do not open all at once. Do not include wilted or dried flowers that remain on the plant, or heads whose flowers have all wilted or dried.

How many fresh flowers or flower heads are present?

Less than 3

3 to 10

More than 10

More...

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 unfolded or open flower parts. Do not include wilted or dried flowers that remain on the plant.

How many fresh flowers are open?

Less than 3

3 to 10

More than 10

Peak flower: The plant has a large number of flowers and one half (50%) or more are open and still fresh.

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Fruits

Do you see...?

Fruits
One or more fresh fruits are visible on the plant.

How many fresh fruits are present?

Less than 3

3 to 10

More than 10

More...

Ripe fruits
One or more ripe fruits are visible on the plant.

How many fruits are ripe?

Less than 3

3 to 10

More than 10

More...

Recent fruit drop
One or more fresh 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.

How many mature fruits have dropped?

Less than 3

3 to 10

More than 10

More...