LINACEAE

FLAX FAMILY

Niall F. McCarten

Annual, perennial herb, shrub
Stem generally erect, branched, glabrous, hairy, or glandular
Leaves generally cauline, alternate, opposite, or whorled, simple, sessile, generally linear to ovate; stipules glandular or 0
Inflorescence: raceme or cyme, axillary, open to dense
Flower generally bisexual, radial, nodding in bud; sepals 4–5, free, glabrous, hairy, or margins gland-toothed; petals 4–5, free, blue, white, yellow, or pink, ephemeral; stamens 4–5, alternate petals, generally appendaged; staminodes alternate stamens or 0; ovary superior, chambers 2–5 but becoming 4–10 by growth of false septa, styles 2–5
Fruit: generally capsule
Genera in family: 13 genera, 300 species: worldwide, especially temp; some cultivated (Linum usitatissimum , flax, linseed; L. bienne, L. grandiflorum , ornamental)
Reference: [Robertson 1971 J Arnold Arbor 52: 649–665]

LINUM

FLAX

Annual, perennial herb
Stem 5–90 cm
Leaves alternate, opposite, or whorled, erect, glabrous or hairy; margins entire or gland-toothed
Inflorescence: raceme or cyme
Flower: sepals 5, margins generally translucent; petals 5, 8–25 mm; stamens 5; staminodes 5 or 0; ovary chambers 10, styles 5, free or not, stigmas > styles in width (spheric or ± elongate) or = styles in width (± linear)
Fruit 5–10 mm
Seeds 10, generally gelatinous when wet
Species in genus: ± 200 species: temp & subtropical, especially Medit. Linum usitatissimum has been reported from D as a garden escape
Etymology: (Latin: flax)

Introduced

L. usitatissimum L.

COMMON FLAX

Annual
Stem glabrous
Leaf 10–35 mm, lanceolate, entire, generally glabrous
Inflorescence: pedicels 20–25 mm
Flower: sepals 6–10 mm; petals 10–15 mm, blue or white; styles fused at base, stigmas elongate
Fruit 7–10 mm
Seed 3.5–4.5 mm
Ecology: Disturbed areas
Elevation: 0–100 m.
Bioregional distribution: California Floristic Province
Distribution outside California: to e N.America; native to Europe