CORN SOW-THISTLE

PERENNIAL SOW-THISTLE

Sonchus arvensis

Daisy & Dandelion [Asteraceae]  

Flowers:
month8jul month8july month8aug month8sep month8sept

Pappus: pappusZpossible (white, simple)
pappus8jul pappus8july pappus8aug pappus8sep pappus8sept pappus8oct

status
statusZnative
 
flower
flower8yellow
 
morph
morph8actino
 
petals
petalsZmany
 
stem
stem8round
 
stem
stem8milkysap stem8milkylatex
 

27th July 2007, Arable Field, near Formby, Lancashire. Photo: © RWD
Grows in margins of arable fields.


27th July 2007, Arable Field, near Formby, Lancashire. Photo: © RWD
Tall to 1.5m with large showy deep-yellow dandelion-type flowers.


7th Aug 2007, Martin Mere, Near Rufford, Lancashire. Photo: © RWD
Lanceolate pinnate leaves are greyish underneath and clasp the stem.


20th Aug 2006, Arable Field, Bispham Green, Near Appley Bridge, Lancashire. Photo: © RWD
Large showy bright-yellow flowers, often looking windswept.


15th July 2009, Arable Field, Near Martin Mere, Rufford, Lancs. Photo: © RWD
Flower buds are ribbed, cylindrical and olive-green with hairs.


20th Aug 2006, Arable Field, Bispham Green, Near Appley Bridge, Lancashire. Photo: © RWD
Large showy flowers.


7th Aug 2007, Martin Mere, Near Rufford, Lancashire. Photo: © RWD
The stems are hairy too.


6th Sept 2005, Rufford Branch of Leeds & L/pool Canal, Tarleton. Photo: © RWD
The hairs are yellow with sticky blobby ends.


24th Aug 2011, Rainford, Merseyside. Photo: © RWD
The bracts immediately beneath the flower are olive green and covered in yellowish sticky glandular hairs.


15th Aug 2014, coastal dunes, Hightown, Sefton Coast. Photo: © RWD
Some bracts go light-brown.


15th July 2009, Arable Field, Near Martin Mere, Rufford, Lancs. Photo: © RWD
Sticky hairs are yellow.


8th July 2016, waste ground, Ellesmere Port, Cheshire. Photo: © RWD
The sticky hairs are broader where they meet the flowerhead. They are hollow and a sticky blob of some pale-yellow coloured resinous substance gathers at the top.


8th July 2016, waste ground, Ellesmere Port, Cheshire. Photo: © RWD
Some hairs are very broad where they are attached to the sepals which is probably a reservoir for the sticky substance.


7th Aug 2007, Martin Mere, Near Rufford, Lancashire. Photo: © RWD
Pinnate lanceolate Leaves clasp the stem, with auricles.


7th Aug 2007, Martin Mere, Near Rufford, Lancashire. Photo: © RWD
Pinnate clasping the stem.


24th Aug 2011, Rainford, Merseyside. Photo: © RWD
A young plant, with stem leaves fully grown but barely off the ground.


24th Aug 2011, Rainford, Merseyside. Photo: © RWD
The seed clock is very dense consisting of hundreds very fine white hairs, some of which can be seen sticking to the sticky glandular hairs of the adjacent spent flower.


27th July 2012, Marshside, Southport. Photo: © RWD
Seeds ready to blow away, indeed, several have done before your Author could take the photo. Seeds brown.


27th July 2012, Marshside, Southport. Photo: © RWD
It seems to the Author that the parachutes with thin white hollow stalks belong to disc florets that didn't get fertilised, whilst those with roughly surfaced ovaloid brown seeds belong to those that were fertilised. Or maybe the white ones have not been pollinated and therefore not ripened into seeds?

Another possibility is that the white ones belong to male-only florets?


Some similarities to : Smooth Sow-Thistle but that has much small flowers that are lemony yellow being even more pale towards the periphery and does not possess sticky hairs.

Slight resemblance to : Prickly Sow-Thistle but that has smaller flowers that although yellow, are not as deeply yellow as Corn Sow-thistle. Prickly Sow-Thistle also has much more robust stems.

Uniquely identifiable characteristics

Distinguishing Feature :

No relation to : Any of the many thistles, apart from both belonging to the Daisy Family.


  Sonchus arvensis  ⇐ Global Aspect ⇒ Asteraceae  

Distribution
family8Daisy family8dandelion family8Asteraceae
 BSBI maps
genus8Sonchus
Sonchus
(Sow-Thistles)

CORN SOW-THISTLE

PERENNIAL SOW-THISTLE

Sonchus arvensis

Daisy & Dandelion [Asteraceae]  

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