SMOOTH SOW-THISTLE

COMMON SOW-THISTLE

Sonchus oleraceus

Daisy & Dandelion Family [Asteraceae]

Flowers:
month8apr month8april month8may month8jun month8june month8jul month8july month8aug month8sep month8sept month8oct month8nov

Pappus: pappusZpossible (white)
pappus8sep pappus8sept pappus8oct pappus8nov pappus8dec

status
statusZnative
 
flower
flower8white
 
inner
inner8yellow
 
morph
morph8actino
 
petals
petalsZMany
 
stem
stem8round
 
stem
stem8hollow
 
stem
stem8milkysap stem8milkylatex
 

5th Sept 2010, Leeds & L/pool canal, Appley Bridge. Photo: © RWD
Grows up to 1.5m tall. Stout and hairless stems; leaves also hairless unless young.


5th Sept 2010, Leeds & L/pool canal, Appley Bridge. Photo: © RWD
Leaves have a satin sheen and are not glossy, un-like Perennial Sow-thistle (Corn Sow-thistle). Leaves are pinnatifid have broad lobes, triangular in overall shape at the termination.


21st Sept 2010, East Lancs Rd, Walkden, Gtr M/cr. Photo: © RWD
The triangular shaped leaves have a stepped or ladder appearance.


5th Sept 2010, Leeds & L/pool canal, Appley Bridge. Photo: © RWD
Leaves are toothed but without spines.


5th Sept 2010, Leeds & L/pool canal, Appley Bridge. Photo: © RWD
Flowers are a paler yellow than those of Rough sow-Thistle, and typically have an even paler halo. Leaves are a grey-green and clasp the stem with two auricles either side of the stem.


5th Sept 2010, Leeds & L/pool canal, Appley Bridge. Photo: © RWD
Any hairs are not sticky (un-like those of Perennial Sow-thistle). When in seed, the flower heads bulge at the bottom to accommodate the seeds.


5th Sept 2010, Leeds & L/pool canal, Appley Bridge. Photo: © RWD
Flowers Dandelion-type and up to an inch across.


5th Sept 2010, Leeds & L/pool canal, Appley Bridge. Photo: © RWD
Florets pale yellow; paler towards the periphery.


5th Sept 2010, Leeds & L/pool canal, Appley Bridge. Photo: © RWD
Like some Hawkweeds, the obverse side of the outer florets sometimes have a pale purple stripe.


5th Sept 2010, Leeds & L/pool canal, Appley Bridge. Photo: © RWD
Stem leaves clasp the stem with two auricles either side.


5th Sept 2010, Leeds & L/pool canal, Appley Bridge. Photo: © RWD
Small leaves just at the node of the (branched) flower stalks.


5th Sept 2010, Leeds & L/pool canal, Appley Bridge. Photo: © RWD
Basal leaves are broad and deeply cut with triangular lobes, ending in a terminating triangle. Leaves are toothed but without spines.


5th Sept 2010, Leeds & L/pool canal, Appley Bridge. Photo: © RWD
Lower leaves usually deeply lobed with a triangular termination.


Hybridizes with : Prickly Sow-Thistle (Sonchus asper) to produce Sonchus asper × glaucescens.

Some similarities to : Prickly Sow-Thistle, Prickly Lettuce and Great Lettuce

Superficial resemblance to : Perennial Sow-thistle

The sap, contained in numerous channels, is milky.

It is also and confusingly called 'Milk Thistle', but true Milk Thistle (Silybum marianum) is a thistle with marbled leaves and a purple thistle-like flower head.

The name Sonchus is derived from the Greek for 'hollow', the Sow-thistles have hollow stems.


  Sonchus oleraceus  ⇐ Global Aspect ⇒ Asteraceae  

Distribution
 family8Daisy & Dandelion family8Asteraceae

 BSBI maps
genus8Sonchus
Sonchus
(Sow-Thistles)

SMOOTH SOW-THISTLE

COMMON SOW-THISTLE

Sonchus oleraceus

Daisy & Dandelion Family [Asteraceae]

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