Sonchus asper |
Sonchus |
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laiteron rude, prickly sow-thistle, sharp-fringe sow thistle, spiny sow-thistle, spiny-leaf sow-thistle |
laiteron, sow-thistle |
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Habit | Annuals or biennials, 10–120(–200+) cm. | Annuals, biennials, or perennials [shrubs], 3–350+ cm; taprooted, rhizomatous, or stoloniferous. | ||||||||||||||||
Stem(s) | bases soft, herbaceous, hollow. |
erect, branched distally or throughout, usually glabrous, sometimes stipitate-glandular (mostly distally). |
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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. |
basal and cauline or mostly cauline; basal usually petiolate (petioles usually winged), cauline often sessile; blades mostly oblong, oblanceolate, or lanceolate, (bases often auriculate) margins usually 1(–2)-pinnately lobed, ultimate margins usually dentate (teeth often ± prickly), sometimes entire. |
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Peduncles | usually stipitate-glandular, sometimes glabrous. |
not notably dilated distally, usually ± bracteolate, glabrous or stipitate-glandular and/or tomentose. |
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Involucres | 9–13+ mm. |
campanulate to urceolate, 5–15+ mm diam. |
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Receptacles | flat to convex, ± pitted, glabrous, epaleate. |
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Florets | [30–]80–250[–450+]; corollas yellow to orange (not deliquescent; anthers yellowish to brownish apically). |
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Corollas | ligules mostly shorter than tubes. |
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Phyllaries | usually stipitate-glandular. |
27–50 in 3–5+ series, unequal, green, deltate to lanceolate or linear, margins sometimes narrowly scarious (sometimes ciliate), apices acute (faces glabrous or stipitate- to setose-glandular). |
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Calyculi | 0. |
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Heads | borne in corymbiform to subumbelliform arrays. |
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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. |
stramineous or reddish to dark brown, ± compressed, mostly oblong or oblanceoloid to ellipsoid, beaks 0, ribs usually 2–4(–5+) on each face, faces sometimes transversely rugulose or tuberculate, glabrous; pappi tardily falling or persistent, of 80–100+, white, smooth or barbellulate bristles (some flattened, ± setiform scales), outer usually distinct in ± 1 series, inner basally coherent or connate, in 2–3+ series. |
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x | = 9. |
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2n | = 18. |
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Sonchus asper |
Sonchus |
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Phenology | Flowering (Mar–)Jul–Nov (year-round in south). | |||||||||||||||||
Habitat | Disturbed sites, roadsides, along streams | |||||||||||||||||
Elevation | 0–2500+ m (0–8200+ 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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Europe (Mediterranean); w Asia; n Africa; Atlantic Islands [Introduced in North America; some species introduced nearly worldwide] |
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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.) |
Species 50–60+ (5 in the flora). Sonchus species are herbs in North America; some are sometimes woody at bases. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Key |
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Source | FNA vol. 19, p. 275. | FNA vol. 19, p. 273. | ||||||||||||||||
Parent taxa | Asteraceae > tribe Cichorieae > Sonchus | Asteraceae > tribe Cichorieae | ||||||||||||||||
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Synonyms | S. oleraceus var. asper | |||||||||||||||||
Name authority | (Linnaeus) Hill: Herb. Brit. 1: 47. (1769) | Linnaeus: Sp. Pl. 2: 793. (1753): Gen. Pl. ed. 5, 347. (1754) | ||||||||||||||||
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