| Sclerolinon | |
|---|---|
 | |
Scientific classification | |
| Kingdom: | Plantae |
| Clade: | Tracheophytes |
| Clade: | Angiosperms |
| Clade: | Eudicots |
| Clade: | Rosids |
| Order: | Malpighiales |
| Family: | Linaceae |
| Subfamily: | Linoideae |
| Genus: | Sclerolinon C.M.Rogers |
| Species: | S. digynum |
| Binomial name | |
| Sclerolinon digynum (A.Gray) C.M.Rogers | |
| Synonyms | |
Linum digynumA.GrayCathartolinum digynumA.Gray | |
Sclerolinon is a monotypic genus of flowering plants in theflax family (Linaceae) containing the single speciesSclerolinon digynum, which is known by the common namesnorthwestern yellowflax[1] andyellow hard flax.[2] It isnative to the western United States, where it has been recorded inWashington,Idaho,Oregon, and as far south as centralCalifornia.[3] It grows in seasonally wet habitats, such as mountainmeadows andvernal pools.[4]
It is an annual herb producing a hairless, erect stem up to 20 cm (7.9 inches) tall. The leaves are oval in shape, and the upper leaves have serrated edges. They are oppositely arranged about the stem and grow erect instead of spreading away from the stem.[5] The inflorescence is acyme of flowers surrounded by serrated, leaflikebracts. The flower has five yellow petals in a calyx of toothedsepals.[6]
S. digynum is the only member of the Linaceae family which has both yellow flowers and serrated leaves.[6]
S. digynum was formerly included in the genusLinum, along with many other flax plants, and many older sources refer to it asLinum digynum. The classification changed in 1966, whenS. digynum was moved into its owngenus due to itsmorphological distinctness.[7][8]
S. digynum has historically been found in the U.S. states of Idaho, Washington, Oregon, and California.
In Idaho it is considered rare, and possiblyextirpated.[3][9] The most recent reports ofS. digynum in Idaho are from the 1800s, when it was seen inKootenai andNez Perce counties.[9]
In Washington,S. digynum is considered sensitive[10] orthreatened.[6] It occurs in theColumbia Plateau ecoregion east of theCascade Range,[10] and has specifically been found inSpokane andWhitman counties.[1][6][5] Here it blooms from May or June through late July.[6][5]
In Oregon, it has been recorded inMarion,Linn,Benton,Klamath,Jackson, andJosephine counties.[1][2]
In California, it has been recorded inGlenn,[11]Siskiyou,Shasta,Plumas,Butte,Sierra,Amador,Calaveras,Tuolomne,Mariposa,Madera, andFresno counties.[1] It blooms from June through August.[12]
