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,
Flowers Are Red in a corner. Finally, the now terrified little boy gives in and tells the teacher that "flowers are red, and green leaves are green." When he goes to a different school, a new teacher encourages her students to use all sorts of colors, only to find the student only coloring his flowers red and green; when the new teacher asks the boy why, he meekly responds by quoting his previous teacher—"flowers are red, and green leaves are green." In the live concert versions, Chapin extended the song's ending to: "There still must be a way to have our children say..."