The green links below add additional plants to the comparison table. Blue links lead to other Web sites.
enable glossary links

common flax, cultivated flax, flax-seed, lin cultivé, lin-seed

King's flax, perennial yellow flax

Habit Herbs, annual, 20–100 cm, glabrous or glabrate throughout. Herbs, perennial, caudex woody, 5–30 cm, glabrous and glaucous.
Stems

erect, unbranched or few-branched at base (all flowering).

ascending to erect from decumbent base, branched from base.

Leaves

divergent;

blade linear to linear-lanceolate, 10–40 × 1.5–5 mm.

alternate throughout or proximal opposite, divergent, erect or spreading;

stipular glands absent;

blade narrowly lanceolate, 5–25 × 1–3 mm, thick (basal leaves), margins entire, not ciliate, apex rounded to subacute; 1-nerved.

Inflorescences

open panicles.

panicles or thyrses.

Pedicels

erect in fruit, to 20–25 mm.

1–5 mm.

Flowers

homostylous;

sepals ovate, 6–9 mm, margins of inner sepals minutely ciliate, outer ciliate, apex acuminate;

petals usually blue, rarely white, obovate, 10–15 mm;

stamens 5–7 mm;

anthers 1–1.5 mm;

staminodia present;

styles distinct or connate at base, 3–6 mm;

stigmas linear or clavate.

sepals persistent, lanceolate to ovate or broadly oblong, 2.5–4.5 mm, margins not scarious, inner glandular-toothed, outer entire or sparsely glandular-toothed near apex, apex acute to ± obtuse, not acuminate;

petals bright yellow, oblanceolate to obovate, 5–12 mm;

stamens 3–8 mm;

anthers 1.5–2.5 mm;

staminodia absent;

styles distinct, 4–7 mm;

stigmas capitate.

Capsules

ovoid to subglobose, 6–10 × 5–10 mm, apex rounded, dehiscing incompletely, segments falling freely, margins ciliate or not.

ovoid-pyriform, 2.3–4 × 2.8–3.6 mm, apex pointed (easily crushed), freely dehiscing into 10, 1-seeded segments, segments persistent on plant, false septa incomplete, proximal margins ciliate.

Seeds

4–6 × 2.5–3 mm.

2–2.7 × 1–1.4 mm.

2n

= 30.

= 26.

Linum usitatissimum

Linum kingii

Phenology Flowering Apr–Sep. Flowering May–Aug.
Habitat Disturbed areas, roadsides, abandoned homesteads, fields. Open slopes, often on barren alkaline clay or rocky calcareous substrates.
Elevation 0–2400 m. (0–7900 ft.) 1400–3400 m. (4600–11200 ft.)
Distribution
from FNA
AL; AR; AZ; CA; CO; CT; DC; DE; FL; GA; IA; ID; IL; IN; KS; KY; LA; MA; MD; ME; MI; MN; MO; MS; MT; NC; ND; NE; NH; NJ; NM; NY; OH; OK; OR; PA; RI; SC; SD; TN; TX; VA; VT; WA; WI; WV; WY; AB; BC; MB; NF; NS; NT; ON; QC; SK; Eurasia [Introduced in North America; introduced also in c Mexico, Central America, s South America, Pacific Islands (New Zealand)]
[WildflowerSearch map]
[BONAP county map]
from FNA
CO; ID; NV; UT; WY
[WildflowerSearch map]
[BONAP county map]
Discussion

Linum usitatissimum has been cultivated since antiquity, and it is this cultivated form that has naturalized in the wild. Flax fibers twisted to make rope or dyed for fabric dated 32,000–26,000 years before present were found in a cave in Dzudzuana, Georgia (E. Kvavadze et al. 2009). Stem fibers of L. usitatissimum are used to make linen; the seeds are pressed to produce linseed oil; the rest of the seeds are compacted into cakes and used as fodder. Linum usitatissimum is the only species in the flora area except L. bienne that has linear stigmas and minutely ciliate inner sepals. It can be distinguished from L. bienne by its larger, apically rounded capsules.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Linum kingii is low, compact, and much branched. All parts of the flowers are yellow. The corolla is nearly rotate, the petals are abruptly narrowed to a claw, the styles are at right angles to the flower axis, and the anthers are relatively large. Linum kingii is extremely variable in habit and in size of floral and vegetative parts, even within a population or within a single plant (C. M. Rogers 1984).

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Source FNA vol. 12, p. 374. FNA vol. 12, p. 382.
Parent taxa Linaceae > Linum > sect. Linum Linaceae > Linum > sect. Linopsis
Sibling taxa
L. alatum, L. allredii, L. arenicola, L. aristatum, L. australe, L. berlandieri, L. bienne, L. carteri, L. catharticum, L. compactum, L. elongatum, L. floridanum, L. grandiflorum, L. harperi, L. hudsonioides, L. imbricatum, L. intercursum, L. kingii, L. lewisii, L. lundellii, L. macrocarpum, L. medium, L. neomexicanum, L. perenne, L. pratense, L. puberulum, L. rigidum, L. rupestre, L. schiedeanum, L. striatum, L. subteres, L. sulcatum, L. trigynum, L. vernale, L. virginianum, L. westii
L. alatum, L. allredii, L. arenicola, L. aristatum, L. australe, L. berlandieri, L. bienne, L. carteri, L. catharticum, L. compactum, L. elongatum, L. floridanum, L. grandiflorum, L. harperi, L. hudsonioides, L. imbricatum, L. intercursum, L. lewisii, L. lundellii, L. macrocarpum, L. medium, L. neomexicanum, L. perenne, L. pratense, L. puberulum, L. rigidum, L. rupestre, L. schiedeanum, L. striatum, L. subteres, L. sulcatum, L. trigynum, L. usitatissimum, L. vernale, L. virginianum, L. westii
Synonyms Cathartolinum kingii, Mesyniopsis kingii
Name authority Linnaeus: Sp. Pl. 1: 277. (1753) S. Watson: Botany (Fortieth Parallel), 49. (1871)
Web links