''Anemonastrum richardsonii'', commonly known as yellow thimbleweed, is named after a

Scottish Scottish usually refers to something of, from, or related to Scotland, including: *Scottish Gaelic, a Celtic Goidelic language of the Indo-European language family native to Scotland *Scottish English *Scottish national identity, the Scottish ide ...

naturalist, Sir John Richardson (1787–1865) who found it on

Franklin's expedition Franklin's lost expedition was a failed British voyage of Arctic exploration led by Captain Sir John Franklin that departed England in 1845 aboard two ships, and , and was assigned to traverse the last unnavigated sections of the Northwest ...

to the Arctic. It is a perennial, deciduous plant that blooms in mid to early June.ITIS report: ''Anemone richardsonii'' Hook
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Description

Yellow thimbleweed is recognized by its small single yellow flowers. These flowers are considered

perfect Perfect commonly refers to: * Perfection, completeness, excellence * Perfect (grammar), a grammatical category in some languages Perfect may also refer to: Film * Perfect (1985 film), ''Perfect'' (1985 film), a romantic drama * Perfect (2018 f ...

, which means they have both male and female reproductive organs. The flower lacks petals but has yellow sepals that act as

petal Petals are modified Leaf, leaves that surround the reproductive parts of flowers. They are often advertising coloration, brightly colored or unusually shaped to attract pollinators. All of the petals of a flower are collectively known as the ''c ...

s and it has a superior ovary. The flower sits on a

stem Stem or STEM may refer to: Plant structures * Plant stem, a plant's aboveground axis, made of vascular tissue, off which leaves and flowers hang * Stipe (botany), a stalk to support some other structure * Stipe (mycology), the stem of a mushro ...

that can grow about high, and is pubescent (covered with tiny hairs). ''Anemonastrum richardsonii'' has

rhizome In botany and dendrology, a rhizome (; , ) is a modified subterranean plant stem that sends out roots and shoots from its nodes. Rhizomes are also called creeping rootstalks or just rootstalks. Rhizomes develop from axillary buds and grow hori ...

s (underground stems) which are thread-like with stalked leaves that are

palmate The following is a list of terms which are used to describe leaf morphology in the description and taxonomy of plants. Leaves may be simple (a single leaf blade or lamina) or compound (with several leaflets). The edge of the leaf may be regular o ...

ly lobed. It also has stem leaves that are 3-parted and sharply toothed in a whorled arrangement below the flowers. The flower develops into an

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 ...

(a dry fruit), which is generally small, long. It is sub-spherical (nearly round), lacks hairs, and is hooked at the tip. The fruit of the yellow thimbleweed is dispersed by wind and has a style that aids in flight.

Habitat

''Anemonastrum richardsonii'' prefers subarctic climates and can be found in willow thickets, snow patches, along streams, near peat and mosses, and in moist areas with low drainage. It is capable of growing under a wide range of soil pH.

Range

Yellow thimbleweed can be found throughout most of Canada, including the Northwest Territories, Yukon, northern Quebec, Labrador, the Nunavut Islands, Melville Island, and Victoria Island Canada, as well as in west Greenland and Alaska (U.S.A.).

Importance to ecosystems

''A. richardsoniis flowers produce much pollen, which attracts some insect pollinators, but they do not produce much nectar; the plant is not generally eaten by vertebrates.

Uses

Herbalists use the plant to soothe abrasions, toothaches, rheumatism, and depression. Traditionally, the roots were boiled and used in an attempt to treat paralysis, though this was ineffective. The smoke from the cotton of the ripe seeds was also burned and inhaled to relieve headaches. ''A. richardsonii'' contains anemonin and protoanemonin, bioactive compounds which have been investigated for potential therapeutic uses; one indication is that anemonin may inhibit pigmentation synthesis.

Conservation

In British Columbia, ''A. richardsonii'' is abundant, secure and widespread; this seems to reflect the status of the species throughout North America, as it is not listed in any vulnerable categories by COSEWIC in Canada or by the United States Department of Agriculture.

References

{{Taxonbar, from=Q91249650 richardsonii Medicinal plants of North America Flora of Canada Flora of Greenland Flora of Alaska