Linum virginianum |
Linum pratense |
|
---|---|---|
Virginia yellow flax, woodland flax, woodland yellow flax |
blue flax, meadow flax, Norton's flax |
|
Habit | Herbs, perennial, 15–80 cm, glabrous. | Herbs, annual, 5–60 cm, glabrous. |
Stems | erect, branches 1–several from base, unbranched proximal to inflorescence. |
± spreading or ascending, or branches from base prostrate. |
Leaves | proximal 4–10 pairs opposite, distal alternate, erect to spreading; stipular glands absent; blade of proximal leaves spatulate, central and distal elliptic, oblanceolate, or obovate, 15–25 × 3–7 mm, margins entire, not ciliate, apex acute to apiculate. |
blade linear to linear-oblanceolate, 8–20 × 0.7–2.3 mm. |
Inflorescences | corymbs. |
open panicles or racemes. |
Pedicels | 1–10 mm. |
8–25 mm. |
Flowers | sepals persistent, lanceolate-ovate, inner shorter, broader, thinner than outer, outer sepals 2–4 mm, margins not scarious, inner sepals usually with a few small, sessile glands along margin distal to middle, rarely eglandular, outer ones entire, apex acute to acuminate; petals yellow, obovate (sometimes notched at apex), 3–5.5 mm; stamens 1.2–3 mm; anthers 0.5–1 mm; staminodia absent; styles distinct, 1–2 mm; stigmas capitate. |
homostylous; sepals ovate, 3–5 mm, margins glabrous, apex acute; petals usually blue, rarely white, obovate, 5–14 mm; stamens 3–5 mm; anthers 0.4–1.3 mm; staminodia present; styles distinct, 1–3 mm; stigmas capitate. |
Capsules | globose, carpels flattened or ± concave abaxially, 1.3–1.8 × 2–2.5 mm, apex depressed, dehiscing freely into 10, 1-seeded segments, segments falling freely, false septa nearly complete, proximal margins usually sparsely and inconspicuously few-ciliate. |
broadly ovate to subglobose, 4–6 mm diam., apex obtuse, segments persistent on plant, margins ciliate. |
Seeds | 1–1.5 × 0.6–0.9 mm. |
3–5 × 1.2–1.6 mm. |
2n | = 36. |
= 18. |
Linum virginianum |
Linum pratense |
|
Phenology | Flowering Jun–Oct. | Flowering Mar–Jun. |
Habitat | Open woods, fields, thickets, roadsides. | Sandy prairies, roadsides, disturbed areas, limestone. |
Elevation | 0–800 m. (0–2600 ft.) | 1200–2000 m. (3900–6600 ft.) |
Distribution |
AL; CT; DC; DE; GA; IA; IL; IN; KY; MA; MD; MI; MO; NC; NJ; NY; OH; PA; RI; SC; TN; VA; WV; ON
|
AZ; CO; KS; NM; OK; TX
|
Discussion | Linum virginianum lacks prominent marginal teeth on the inner sepals, thus distinguishing it from L. striatum. It has a less elongate inflorescence and lacks the ribbed branchlets found in L. striatum (C. M. Rogers 1984). The corollas of L. virginianum are nearly rotate; all parts of the flower are yellow except the brownish anthers. Its capsules shatter readily and often are absent on herbarium sheets. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
In a study of pollination in Linum pratense, G. E. Uno (1984) observed that petals dropped soon after anthesis and the persistent sepals quickly moved inward, pressing the dehiscing anthers against the receptive stigmas. Small bees and flies were seen to visit flowers even after the petals fell. Uno noted sepals closing in both L. lewisii and L. rigidum, but in these species the stamens tend to be somewhat shorter than the styles so self-pollination was less likely. C. M. Rogers (1984) wrote that some plants of Linum pratense intergrade with L. lewisii in areas where their ranges overlap; however, in most of its range, L. pratense is the only blue-flowered Linum, and can be distinguished from the occasional plant of L. bienne or L. usitatissimum by its lack of cilia on the inner sepals and its capitate stigmas. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 12, p. 385. | FNA vol. 12, p. 376. |
Parent taxa | Linaceae > Linum > sect. Linopsis | Linaceae > Linum > sect. Linum |
Sibling taxa | ||
Synonyms | Cathartolinum virginianum | L. lewisii var. pratense |
Name authority | Linnaeus: Sp. Pl. 1: 279. (1753) | (Norton) Small: in N. L. Britton et al., N. Amer. Fl. 25: 69. (1907) |
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