Clarkia pulchella also known as pinkfairies, ragged robin, and deerhorn clarkia is a species of flowering plant in the Onagraceae

Onagraceae

Onagraceae, also known as the Willowherb family or Evening Primrose family, are a family of flowering plants. The family includes about 640-650 species of herbs, shrubs, and trees in 20-24 genera...

 family. This wildflower is found in the Pacific Northwest

Pacific Northwest

The Pacific Northwest is a region in northwestern North America, bounded by the Pacific Ocean to the west and, loosely, by the Rocky Mountains on the east. Definitions of the region vary and there is no commonly agreed upon boundary, even among Pacific Northwesterners. A common concept of the...

 and is the type species

Type species

In biological nomenclature, a type species is both a concept and a practical system which is used in the classification and nomenclature of animals and plants. The value of a "type species" lies in the fact that it makes clear what is meant by a particular genus name. A type species is the species...

 of Clarkia. It was first discovered by Meriweather Lewis close to Kamiah, Idaho

Idaho

Idaho is a state in the Rocky Mountain area of the United States. The state's largest city and capital is Boise. Residents are called "Idahoans". Idaho was admitted to the Union on July 3, 1890, as the 43rd state....

 during the Lewis and Clark expedition

Lewis and Clark Expedition

The Lewis and Clark Expedition, or ″Corps of Discovery Expedition" was the first transcontinental expedition to the Pacific Coast by the United States. Commissioned by President Thomas Jefferson and led by two Virginia-born veterans of Indian wars in the Ohio Valley, Meriwether Lewis and William...

 and it was subsequently brought back as a botanical specimen. The discovery was first described on May 28, 1806 by William Clark and subsequently by Lewis on June 1, 1806 in a journal entry stating that:

I met with a singular plant today in blume of which I preserved a specemine; it grows on the steep sides of the fertile hills near this place, the radix is fibrous, not much branched, annual, woody, white and nearly smooth. the stem is simple branching ascending, 2½ feet high celindric, villose and of a pale red colour. the branches are but few and those near it's upper extremity. the extremities of the branches are flexible and are bent down near their extremities with the weight of the flowers. the leaf is sissile, scattered thinly, nearly linear tho' somewhat widest in the middle, two inches in length absolutely entire, villose, obtusely pointed and of an ordinary green. above each leaf a small short branch protrudes, supporting a tissue of four or five smaller leaves of the same apeparance with those described. a leaf is placed underneath eah branch, and each flower. the calyx is a one flowered spathe. the corolla superior consists of four pale perple petals which are tripartite, the central lobe largest and all terminate obtusely; they are inserted with a long and narrow claw on the top of the germ, are long, smooth, & deciduous. there are two distinct sets of stamens the 1st or principal consist of four, the filaments of which are capillary, erect, inserted on the top of the germ alternately with the petals, equal short, membranous; the anthers are also four each being elivated with it's fillament, they are linear and reather flat, erect sessile, cohering at the base, membranous, longitudinally furrowed, twice as long as the fillament naked, and of a pale perple colour. the second set of stamens are very minute are also four and placed within and opposite to the petals, these are scarcely persceptable while the 1st are large and conspicuous; the filaments are capillary equal, very short, white and smooth. the anthers are four, oblong, beaked, erect, cohering at the base, membranous, shorter than the fillaments, white naked and appear not to form pollen. there is one pistillum; the germ of which is also one, cilindric, villous, inferior, sessile, as long as the 1st stamens, and marked with 8 longitudinal furrows. the single style and stigma form a perfect monapetallous corolla only with this difference, that the style which elivates the stigma or limb is not a tube but solid tho' it's outer appearance is that of the tube of a monopetallous corolla swelling as it ascends and gliding in such manner into the limb that it cannot be said where the style ends, or the stigma begins; jointly they are as long as the corolla, white, the limb is four cleft, sauser shaped, and the margins of the lobes entire and rounded. this has the appearance of a monopetallous flower growing from the center of a four petalled corollar, which is rendered more conspicuous in consequence of the 1st being white and the latter of a pale perple. I regret very much that the seed of this plant are not yet ripe and it is proble will not be so during my residence in this neighbourhood.

It was not until 1814 however that the plant was classified and named Clarckia pulchella by Frederick Traugott Pursh

Frederick Traugott Pursh

Frederick Traugott Pursh was a German-American botanist.Born in Grossenhain, Saxony, to the name Friedrich Traugott Pursh, he was educated at Dresden Botanical Gardens, and emigrated to the United States in 1799...

 in honor of Clark even though in his journal entry he acknowledged Lewis as the discoverer. At the time of its publication by Pursh it was the first species assigned to the newly created genus Clarckia. The genus was later renamed as Clarkia. Then in 1826 David Douglas

David Douglas

David Douglas was a Scottish botanist. He worked as a gardener, and explored the Scottish Highlands, North America, and Hawaii, where he died.-Early life:...

 brought back samples of the plant to England

England

England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west, with the North Sea to the east and the English Channel to the south separating it from continental...

 after an expedition to the northwest United States from 1824 to 1828.

Clarkia pulchella is most famous for its use by botanist Robert Brown

Robert Brown (botanist)

Robert Brown was a Scottish botanist and palaeobotanist who made important contributions to botany largely through his pioneering use of the microscope...

 in the discovery of Brownian motion

Brownian motion

Brownian motion or pedesis is the presumably random drifting of particles suspended in a fluid or the mathematical model used to describe such random movements, which is often called a particle theory.The mathematical model of Brownian motion has several real-world applications...

. Brown studied the pollen of Clarkia pulchella while immersed in water under the microscope. He used these pollen granules because they contain oblong particles, which he observed were 6 to 8 micrometres in length, and he thought that he could follow their progress during fertilization, which was the initial subject of his investigation. The plant is also known for its use by Newman and Pilson to demonstrate a causal relationship between genetic variation in a population and population survival.