Flax have been domesticated just once from the wild species "Linum bienne", called pale flax. Several other species in the genus "Linum" are similar in appearance to "L. usitatissimum", cultivated flax, including some that have similar blue flowers, and others with white, yellow, or red flowers. Some of these are perennial plants, unlike "L. usitatissimum", which is an annual plant. Cultivated flax plants grow to tall, with slender stems. The leaves are glaucous green, slender lanceolate, 20–40 mm long, and 3 mm broad. The flowers are pure pale blue, 15–25 mm in diameter, with five petals. The fruit is a round,
Language of flowers "The Language of Flowers." First published in 1884, it continues to be reprinted to this day. In the United States the first print appearance of the language of flowers was in the writings of Constantine Samuel Rafinesque, a French-American naturalist, who wrote on-going features under the title "The School of Flora," from 1827 through 1828, in the weekly Saturday Evening Post and the monthly "Casket; or Flowers of Literature, Wit, and Sentiment." These pieces contained the botanic, English, and French names of the plant, a description of the plant, an explanation of its Latin names, and the flower's emblematic meaning.