This section is from the book "An Illustrated Flora Of The Northern United States, Canada And The British Possessions Vol2", by Nathaniel Lord Britton, Addison Brown. Also available from Amazon: An Illustrated Flora of the Northern United States, Canada and the British Possessions. 3 Volume Set..
Annual or perennial herbs, sometimes woody at the base, with alternate or opposite, rarely verticillate, sessile leaves, and perfect flowers. Inflorescence axillary or terminal. Stipules or stipular glands wanting. Sepals 5, persistent. Petals 5, blue, red or rarely white, fugacious. Stamens 5, monadelphous, with interspersed staminodia. Ovary 5-celled, or 8-10-celled by false partitions, not cartilaginous at the base, the real cavities 2-ovuled. Capsule * Revised by Dr. John K. Small.
5-10-valved, the carpels with incomplete false septa, each one longitudinally ridged and grooved on the back. Seeds flat, lenticular. [The classical Latin name.]
About 8 species, natives of temperate or warm regions. In addition to the following another occurs in the western United States. Type species: Linum usitatissimum L.
Annual; introduced; inner sepals ciliate; capsule about as long as the calyx.
Perennial; western; sepals eciliate; capsule much exceeding the calyx.
Linum usitatissimum L. Sp. Pl. 277. 1753.
Annual, often tufted, erect, branching above, 12'-20' high, glabrous and somewhat glaucous. Stem terete, striate, the branches slightly angular; leaves alternate, 3-nerved, lanceolate, 1/2'-1 1/2' long, 1"-3" wide, acute or acuminate; stipules none; inflorescence a terminal cy-mose leafy panicle; flowers blue, 6"-8" broad; pedicels slender; sepals oval, acuminate, the interior ones ciliate and 3-ribbed; petals cu-neate, crenulate, twice the length of the sepals; capsule ovoid-conic, 3"-4." long, equalling or somewhat exceeding the sepals, indehiscent, incompletely 10-celled, the septa not ciliate; seeds compressed.
Linum humile Mill., another Old World species, may be distinguished by its dehiscent capsule with ciliate septa. It is rarely met with in our area in similar situations. Both have been cultivated since prehistoric times for their fibre and oil. Their origin is unknown.
Linum grandiflōrum Desf., originally from northern Africa and also occasionally met with in our area, may be distinguished from both L. usitatissimum and L. humile by its red petals, the ciliate outer sepals and the united styles.
Linum Lewisii Pursh, Fl. Am. Sept. 210. 1814. Linum perenne var Lewisii Eat & Wright. N A. Bot. 302. 1840.
Perennial by a woody root, 1°-2° high, glabrous, glaucous, densely tufted, simple up to the cymose inflorescence. Leaves crowded, oblong or linear, 3"-2o" long. \"-2" wide, acute or acutish, 3-5-nerved; flowers blue, 1'-1 1/2' broad; sepals oval, mainly obtuse, one-third or one-fourth the length of the petals; stigmas shorter than the styles; capsule broadly ovoid, 2-3 times as long as the calyx, obtuse, incompletely 10-celled, dehiscent, the septa ciliate.
Prairies, Manitoba to South Dakota, Wisconsin, Texas, Arizona, Utah and Alaska. Prairie-flax. Summer.
The European L. perenne L., otherwise nearly identical with this species, differs in having heterogenous flowers.