''Anemone occidentalis'', the white pasqueflower or western pasqueflower, is a

herbaceous Herbaceous plants are vascular plants that have no persistent woody stems above ground. This broad category of plants includes many perennials, and nearly all annuals and biennials. Definitions of "herb" and "herbaceous" The fourth edition of t ...

species of

flowering plant Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (), commonly called angiosperms. The term "angiosperm" is derived from the Greek words ('container, vessel') and ('seed'), and refers to those plants th ...

in the buttercup family

Ranunculaceae Ranunculaceae (buttercup or crowfoot family; Latin "little frog", from "frog") is a family of over 2,000 known species of flowering plants in 43 genera, distributed worldwide. The largest genera are ''Ranunculus'' (600 species), ''Delphinium' ...

. Other authorities place it in the genus ''

Pulsatilla The genus ''Pulsatilla'' contains about 40 species of herbaceous perennial plants native to meadows and prairies of North America, Europe, and Asia. Derived from the Hebrew word for Passover, "pasakh", the common name pasque flower refers to the ...

''. Individuals are tall, from

caudices A caudex (plural: caudices) of a plant is a stem, but the term is also used to mean a rootstock and particularly a basal stem structure from which new growth arises.pages 456 and 695 In the strict sense of the term, meaning a stem, "caudex" is ...

, with three to six leaves at the base of the plant that are 3-foliolate, each leaflet pinnatifid to dissected in shape. Leaf petioles are long. Leaves have villous hairs and their margins are pinnatifid or dissected. Plants flower briefly mid-spring to mid-summer, usually soon after the ground is exposed by melting snow. The flowers are composed of five to seven sepals (sometimes called

tepal A tepal is one of the outer parts of a flower (collectively the perianth). The term is used when these parts cannot easily be classified as either sepals or petals. This may be because the parts of the perianth are undifferentiated (i.e. of very ...

s), normally white or soft purple, also mixed white and blueish purple, one flower per stem. The sepals are long and wide. Flowers have 150–200 stamens. The fruit occurs in heads rounded to subcylindric in shape, with pedicels long. The

achene An achene (; ), also sometimes called akene and occasionally achenium or achenocarp, is a type of simple dry fruit produced by many species of flowering plants. Achenes are monocarpellate (formed from one carpel) and indehiscent (they do not ope ...

s are ellipsoid in shape, not winged, covered with villous hairs, with beaks curved that reflex as they age and long, feather-like. Generally, the fruit persists into fall. Native to far western North America including British Columbia to California and Montana, it is found growing in gravelly soils on slopes and in moist meadows.

Chemistry

Western pasqueflower likely contains

ranunculin Ranunculin is an unstable glucoside found in plants of the buttercup family (Ranunculaceae). On maceration, for example when the plant is wounded, it is enzymatically broken down into glucose and the toxin protoanemonin Protoanemonin (sometimes ...

and

protoanemonin Protoanemonin (sometimes called anemonol or ranunculol) is a toxin found in all plants of the buttercup family (Ranunculaceae). When the plant is wounded or macerated, the unstable glucoside found in the plant, ranunculin, is enzymatically broken d ...

, an irritant

glycoside In chemistry, a glycoside is a molecule in which a sugar is bound to another functional group via a glycosidic bond. Glycosides play numerous important roles in living organisms. Many plants store chemicals in the form of inactive glycosides. ...

and its

aglycone An aglycone (aglycon or genin) is the compound remaining after the glycosyl group on a glycoside is replaced by a hydrogen atom. For example, the aglycone of a cardiac glycoside would be a steroid molecule. Detection A way to identify aglycone ...

, as these are seen in most members of this genus and the plant's latex is irritating. It can be fatal to domestic animals, particularly to sheep, and should thus not be eaten by humans.

Traditional medicine

The fresh stems and seeds of the plant are used traditionally in North America as analgesics, anxiolytics, and sedatives.

Landmarks

Pulsatilla Pass in

Banff National Park Banff National Park is Canada's oldest National Parks of Canada, national park, established in 1885 as Rocky Mountains Park. Located in Alberta's Rockies, Alberta's Rocky Mountains, west of Calgary, Banff encompasses of mountainous terrain, wi ...

is named after this species.

Image gallery

Anemone occidentalis in Kootenay National Park.jpg, Anemone occidentalis in

Kootenay National Park Kootenay National Park is a national park of Canada located in southeastern British Columbia. The park consists of of the Canadian Rockies, including parts of the Kootenay and Park mountain ranges, the Kootenay River and the entirety of the Ve ...

, Canada Anemone occidentalis flower (Yarnell).jpg, ''Anemone occidentalis'' flower Anemone occidentalis in Garibaldi Provincial Park (DSCF1755).jpg, ''Anemone occidentalis'' flowers Anemone occidentalis fruit cross-section (Yarnell).jpg, ''Anemone occidentalis'' on

Mount Rainier Mount Rainier (), indigenously known as Tahoma, Tacoma, Tacobet, or təqʷubəʔ, is a large active stratovolcano in the Cascade Range of the Pacific Northwest, located in Mount Rainier National Park about south-southeast of Seattle. With a s ...

with some achenes cut away to show the receptacle and seeds. Pulsatilla_occidentalis_20968.JPG, The persistent

and foliage are distinguishing features.

References

External links

occidentalis This list of Latin and Greek words commonly used in systematic names is intended to help those unfamiliar with classical languages to understand and remember the scientific names of organisms. The binomial nomenclature used for animals and plants i ...

Flora of Western Canada Flora of the Northwestern United States Flora of the Southwestern United States {{Ranunculales-stub