Purshia tridentata
Encyclopedia
Purshia tridentata is a nitrogen fixing
shrub
in the genus Purshia
, native to mountainous areas of western North America
ranging from southeastern British Columbia
in the north, east to Montana
and south to California
and New Mexico
. It grows on arid mountainsides; in California it occurs between 700–3,400 m above sea level (Jepson), but lower further north, at 320–1,065 m in British Columbia (Plants of British Columbia).
Common names include Antelope Brush, Antelope Bitterbrush, Buckbrush, Quinine Brush, and less commonly Deerbrush, Blackbrush, and Greasewood. Some of these names are shared with other closely related species.
It is a low, deciduous
shrub growing to a height of 1–5 m, with slender three- to five-lobed leaves
5–20 mm long. The flower
s are pale yellow, with five petals 6–8 mm long, and darker yellow anthers. The fruit
is a cluster of dry, slender, leathery achene
s 0.6–2 cm long.
Nitrogen fixation
Nitrogen fixation is the natural process, either biological or abiotic, by which nitrogen in the atmosphere is converted into ammonia . This process is essential for life because fixed nitrogen is required to biosynthesize the basic building blocks of life, e.g., nucleotides for DNA and RNA and...
shrub
Shrub
A shrub or bush is distinguished from a tree by its multiple stems and shorter height, usually under 5–6 m tall. A large number of plants may become either shrubs or trees, depending on the growing conditions they experience...
in the genus Purshia
Purshia
Purshia is a small genus of 5-8 species of flowering plants in the family Rosaceae, native to western North America, where they grow in dry climates from southeast British Columbia in Canada south throughout the western United States to northern Mexico. The classification of Purshia within the...
, native to mountainous areas of western North America
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...
ranging from southeastern British Columbia
British Columbia
British Columbia is the westernmost of Canada's provinces and is known for its natural beauty, as reflected in its Latin motto, Splendor sine occasu . Its name was chosen by Queen Victoria in 1858...
in the north, east to Montana
Montana
Montana is a state in the Western United States. The western third of Montana contains numerous mountain ranges. Smaller, "island ranges" are found in the central third of the state, for a total of 77 named ranges of the Rocky Mountains. This geographical fact is reflected in the state's name,...
and south to California
California
California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...
and New Mexico
New Mexico
New Mexico is a state located in the southwest and western regions of the United States. New Mexico is also usually considered one of the Mountain States. With a population density of 16 per square mile, New Mexico is the sixth-most sparsely inhabited U.S...
. It grows on arid mountainsides; in California it occurs between 700–3,400 m above sea level (Jepson), but lower further north, at 320–1,065 m in British Columbia (Plants of British Columbia).
Common names include Antelope Brush, Antelope Bitterbrush, Buckbrush, Quinine Brush, and less commonly Deerbrush, Blackbrush, and Greasewood. Some of these names are shared with other closely related species.
It is a low, deciduous
Deciduous
Deciduous means "falling off at maturity" or "tending to fall off", and is typically used in reference to trees or shrubs that lose their leaves seasonally, and to the shedding of other plant structures such as petals after flowering or fruit when ripe...
shrub growing to a height of 1–5 m, with slender three- to five-lobed leaves
Leaf
A leaf is an organ of a vascular plant, as defined in botanical terms, and in particular in plant morphology. Foliage is a mass noun that refers to leaves as a feature of plants....
5–20 mm long. The flower
Flower
A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants . The biological function of a flower is to effect reproduction, usually by providing a mechanism for the union of sperm with eggs...
s are pale yellow, with five petals 6–8 mm long, and darker yellow anthers. The fruit
Fruit
In broad terms, a fruit is a structure of a plant that contains its seeds.The term has different meanings dependent on context. In non-technical usage, such as food preparation, fruit normally means the fleshy seed-associated structures of certain plants that are sweet and edible in the raw state,...
is a cluster of dry, slender, leathery achene
Achene
An achene is a type of simple dry fruit produced by many species of flowering plants. Achenes are monocarpellate and indehiscent...
s 0.6–2 cm long.
