I met with a singular plant today in blume," wrote Meriwether Lewis on June 1, 1806, "of which I preserved a specemine. It grows on the steep sides of the fertile hills near this place." He described the root, stem, branches and leaves, and finally the parts of the delicate flower:
Above is the dried specimen of the "singular plant" that Lewis collected, and which, in 1814, botanist Frederick Pursh named Clarkia pulchella. The label at lower left, applied to the original specimen sheet in 1896 by botanist Thomas Meehan of the Academy of Natural Sciences, reads "Clarkia pulchella Pursh." An additional label, not shown here, which possibly was written by Pursh, says "A beautifull herbaceous plant from the Kooskooskee & Clark's R. Jun. 1st 1806."
A Family Matter
In some parts of its native range—the Rocky Mountains of British Columbia, Idaho, and western Montana—Clarkia pulchella is sometimes called "ragged robin." Elsewhere that common name is applied universally to Silene flos-cuculi (Sigh-lean-ee flohss-coo-coo-lee), a native of the British Isles. The two plants belong to different plant families.
Clarkia is a member of the family Onagraceae (oh-nah-gray-see-ee), which includes the fuchsia and the evening primrose. Silene belongs to the pink family, the scientific designation for which is Caryophyllaceae (keh-ree-oh-fill-ay-see-ee).
In Clarkia pulchella, the four lavender to rose-purple petals are three-lobed and taper to a long, claw-like base where a pair of short, blunt teeth also are present. There are four stamens, with a single, prominent, white, four-cleft stigma dominating the center of the flower.
In Silene flos-cuculi, the five short-clawed petals are rose pink, with each petal deeply four-cleft. There are five stamens and five small, essentially head-like stigmas. As may be seen, the two flowers are markedly different.
—James L. Reveal, 07/05