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

stiffstem flax

French flax

Habit Herbs, annual, 15–50 cm, glabrous throughout or puberulent near base of stem. Herbs, annual, 10–50 cm, glabrous.
Stems

erect, branches few, fastigiate or spreading-ascending.

erect or spreading, few-branched.

Leaves

alternate, erect;

stipular glands present or absent;

blade linear, 11–30 × 0.7–1.6 mm, margins entire or distally sparsely toothed, not ciliate, apex acute.

alternate, spreading to ascending;

stipular glands absent;

blade linear-lanceolate to narrowly elliptic, 5–10 × 1–1.5 mm, margins entire, not ciliate, apex acuminate.

Inflorescences

panicles or cymes.

panicles.

Pedicels

4.5–9 mm.

1–5 mm.

Flowers

sepals deciduous, lanceolate to broadly lanceolate, 5.5–9.5 mm, margins of inner sepals conspicuously scarious, all conspicuously glandular-toothed, apex sharply acute to acuminate;

petals coppery yellow or orange, red-lined or with short pale to deep brown-red zone at base, obovate with short claw, 6–18 mm;

stamens 6–8 mm;

anthers 1–1.8(–2.3) mm;

staminodia absent;

styles connate nearly to apex, 3–11 mm;

stigmas pale, capitate.

sepals persistent, lanceolate to ovate, 3–4 mm, margins of inner sepals broadly scarious, densely glandular-ciliate, glandular-toothed, apex acuminate to setaceous;

petals lemon yellow, oblong to obovate, 4–6 mm;

stamens 1.5 mm;

anthers 0.3 mm;

staminodia present or absent;

styles distinct, 1 mm;

stigmas linear.

Capsules

ellipsoid, 3.5–4.5 × 2.6–3.4 mm, apex obtuse, dehiscing into 5, 2-seeded segments, segments blunt or subacute, persistent on plant, false septa complete, proximal part membranaceous, not terminating in loose fringe, distal part cartilaginous, margins not ciliate.

subglobose, 2 mm diam., apex sharp-pointed (easily crushed), readily dehiscing into 5, 2-seeded segments, segments persistent on plant, false septa incomplete, margins of true septa ciliate.

Seeds

2.6–3.6 × 0.9–1.2 mm.

1.1 × 0.9–1 mm.

2n

= 30.

= 20.

Linum rigidum

Linum trigynum

Phenology Flowering May–Jul.
Habitat Grasslands.
Elevation 100–200 m. (300–700 ft.)
Distribution
from FNA
AR; CO; IA; IL; KS; MN; MO; MT; ND; NE; NM; OK; SD; TX; WI; WY; AB; MB; SK; n Mexico
[WildflowerSearch map]
[BONAP county map]
from FNA
CA; s Europe; w Asia; n Africa [Introduced in North America; introduced also in Pacific Islands (Hawaii, New Zealand), Australia]
[BONAP county map]
Discussion

Varieties 2 (2 in the flora).

The corollas of Linum rigidum are funnelform at the base, opening out into a broader bowl. The styles and stamens are yellow, although the distinct portion of the style may be slightly maroon; the stigmas are grayish or light green. The stems of L. rigidum are angled. Its capsule walls are so thin that the dark seeds can be seen through them. C. M. Rogers (1984) noted that L. australe, L. berlandieri, L. compactum, and both varieties of L. rigidum are closely related, and that there is some overlap in character expressions, not easily resolved in a dichotomous key.

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

Linum trigynum is one of three species in sect. Linopsis subsect. Halolinum (Planchon) C. M. Rogers. This section is characterized as having separate styles, linear stigmas, and incomplete false septa. Linum trigynum is homostylous; the other two species, L. maritimum Linnaeus and L. tenue Desfontaines, are heterostylous. Two populations of L. trigynum have been reported in Sonoma County on the Jenner and Fort Ross State Historic Park headlands, both with hundreds of individuals and apparently persisting. Where native, the species sometimes occurs on serpentine soils, and it is reported as a weed in western Australia.

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

Key
1. Stipular glands absent; styles 5–11 mm; stigmas light gray.
var. rigidum
1. Stipular glands nearly always present; styles 3–5 mm; stigmas light green.
var. simulans
Source FNA vol. 12, p. 391. FNA vol. 12, p. 394.
Parent taxa Linaceae > Linum > sect. Linopsis 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. rupestre, L. schiedeanum, L. striatum, L. subteres, L. sulcatum, L. trigynum, L. usitatissimum, 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. 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. usitatissimum, L. vernale, L. virginianum, L. westii
Subordinate taxa
L. rigidum var. rigidum, L. rigidum var. simulans
Synonyms L. gallicum
Name authority Pursh: Fl. Amer. Sept. 1: 210. (1813) Linnaeus: Sp. Pl. 1: 279. (1753)
Web links