Sonchus asper |
Sonchus oleraceus |
|
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laiteron rude, prickly sow-thistle, sharp-fringe sow thistle, spiny sow-thistle, spiny-leaf sow-thistle |
annual sow-thistle, common sow-thistle, laiteron, sow thistle |
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Habit | Annuals or biennials, 10–120(–200+) cm. | Annuals or biennials, 10–140(–200) cm. |
Stem | bases soft, herbaceous, hollow. |
bases soft to hard, herbaceous, often hollow. |
Leaves | blades of mid cauline spatulate or oblong to obovate or lanceolate, 6–30 × 1–15 cm, bases auriculate, auricles often recurved or curled, rounded, margins often pinnately lobed, lobes ± deltate (not constricted at bases), terminals usually larger than laterals, usually prickly-dentate. |
blades of mid cauline spatulate or oblong to obovate or lanceolate, 6–35 × 1–15 cm, bases auriculate, auricles deltate to lanceolate, ± straight, acute, margins usually pinnately (often runcinately) lobed, lobes ± deltate to lanceolate, not constricted at bases, terminals usually larger than laterals, entire or dentate. |
Peduncles | usually stipitate-glandular, sometimes glabrous. |
usually glabrous, sometimes stipitate-glandular. |
Involucres | 9–13+ mm. |
9–13+ mm. |
Corollas | ligules mostly shorter than tubes. |
ligules ± equaling tubes. |
Phyllaries | usually stipitate-glandular. |
usually glabrous, sometimes tomentose and/or stipitate-glandular. |
Cypselae | stramineous to reddish brown, mostly ellipsoid, strongly compressed, ± winged, 2–3 mm, ribs 3(–5) on each face, faces smooth across and between ribs; pappi 6–9 mm. |
dark brown, mostly oblanceoloid, 2.5–3.5+ mm, ribs 2–4 on each face, faces transversely rugulose or tuberculate across and between ribs; pappi 5–8 mm. |
2n | = 18. |
= 32, 36. |
Sonchus asper |
Sonchus oleraceus |
|
Phenology | Flowering (Mar–)Jul–Nov (year-round in south). | Flowering (Apr–)Jul–Oct (year-round in south). |
Habitat | Disturbed sites, roadsides, along streams | Disturbed sites, gardens, roadsides, along streams |
Elevation | 0–2500+ m (0–8200+ ft) | 0–2000 m (0–6600 ft) |
Distribution |
AK; 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; ND; NE; NH; NJ; NM; NV; NY; OH; OK; OR; PA; RI; SC; SD; TN; TX; UT; VA; VT; WA; WI; WV; WY; AB; BC; MB; NB; NL; NS; ON; PE; QC; SK; YT; SPM; Europe; w Asia; n Africa [Introduced in North America; introduced also in Mexico, Central America, West Indies, Bermuda, South America, e Asia, s Africa, Pacific Islands (New Zealand), Australia]
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AK; 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; ND; NE; NH; NJ; NM; NV; NY; OH; OK; OR; PA; RI; SC; SD; TN; TX; UT; VA; VT; WA; WI; WV; WY; AB; BC; MB; NB; NF; NS; NT; ON; PE; QC; SK; SPM; Greenland; Europe [Introduced in North America; introduced also in Mexico, West Indies, Bahamas, Central America, South America, Africa, Asia, Pacific Islands (New Zealand), Australia]
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Discussion | L. Boulos (1973) distinguished subsp. asper (annuals with leaves mostly cauline, cypselae margins little or not at all curved and/or ciliate, and one pair of chromosomes with small satellites) from subsp. glaucescens (biennials with leaves mostly in rosettes, leaves mostly stiffer and more prickly than in subsp. asper, cypselae with curved, ciliate margins, and two pairs of chromosomes with large satellites) and noted that the two subspecies are morphologically rather difficult to distinguish if the specimen in hand lacks the rootstock or stem base. According to H. N. Barber (1941), crosses between Sonchus asper and S. oleraceus resulted in sterile hybrids. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
|
Source | FNA vol. 19, p. 275. | FNA vol. 19, p. 275. |
Parent taxa | Asteraceae > tribe Cichorieae > Sonchus | Asteraceae > tribe Cichorieae > Sonchus |
Sibling taxa | ||
Synonyms | S. oleraceus var. asper | |
Name authority | (Linnaeus) Hill: Herb. Brit. 1: 47. (1769) | Linnaeus: Sp. Pl. 2: 794. (1753) |
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