Linum sect. Linum

Treatment appears in FNA Volume 12. Treatment on page 373.

Herbs, annual, biennial, or perennial. Stems usually terete (ridged in L. grandiflorum). Leaves alternate; stipular glands absent; blade margins entire, not glandular-toothed. Flowers homostylous or heterostylous; sepals persistent, margins scarious, entire, not glandular-toothed; petals usually blue or red to maroon, rarely white; staminodia present or absent; styles distinct, connate basally or to midlength; stigmas capitate, clavate, or linear. Capsules dehiscing into 10, 1-seeded segments; false septa incomplete. Pollen tricolpate.


North America, Mexico, Eurasia, n Africa, Pacific Islands (New Zealand), Australia, introduced in s South America.


Species ca. 50 (6 in the flora).


1 Petals bright red to maroon, fading to purple. Linum grandiflorum
1 Petals usually blue, rarely white. > 2
2 Stigmas linear or clavate; margins of inner sepals minutely ciliate. > 3
3 Annuals; petals 10–15 mm; capsules 6–10 mm, apices rounded; seeds 4–6 mm. Linum usitatissimum
3 Biennials or short-lived perennials; petals 6–10 mm; capsules 4–6 mm, apices very sharp-pointed; seeds 2.5–3 mm. Linum bienne
2 Stigmas capitate or ellipsoid-capitate, margins of inner sepals glabrous. > 4
4 Flowers heterostylous. Linum perenne
4 Flowers homostylous. > 5
5 Perennials; styles 2–12 mm, capsule apices acute. Linum lewisii
5 Annuals; styles 1–3 mm; capsule apices obtuse. Linum pratense