Prickly Sow-thistle

Prickly Sow-thistle - Sonchus asper

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Description

Short to tall plant, hairless except for a few glandular hairs on the upper stem. Stem angled, often reddening, sometimes branched to 1.2 metres. The upper leaves are shiny green and prickly they clasp the stem with rounded basal lobes. Flowerheads golden yellow, 20 to 25 mm in lax clusters, bracts without glandular hairs.

Similar Species

Smooth Sow-thistle 

Identification difficulty
ID checklist (your specimen should have all of these features)

Auricles of stem-leaves rounded.  Achenes not rugose. Leaves can be very similar to S oleraceus but usually more sharply toothed

Recording advice

Photograph of stem and leaves, showing auricles

Habitat

Cultivated and waste land, roadsides.

When to see it

June to August.

Life History

Annual.

UK Status

Very common throughout Britain except in some parts of the Scottish Highlands.

VC55 Status

Very common in Leicestershire and Rutland. In the 1979 Flora survey of Leicestershire it was found in 583 of the 617 tetrads.

  • Graham Calow
    Sapcote
    02 June 2006
  • Peter Smith
    Loughborough Big Meadow
    26 May 2012
    round auricle at base of leaf
  • HAPeacock
    Leicester Garden
    10 June 2012
  • David Gould
    Aylestone Meadows
    15 August 2014
    leaf with rounded basal lobe
  • David Gould
    Croft Pasture
    26 June 2014

Leicestershire & Rutland Map

MAP KEY:

Yellow squares = NBN records (all known data)
Coloured circles = NatureSpot records: 2025+ | 2020-2024 | pre-2020

UK Map

Additional images

All NatureSpot records

Photo of the association

Cystiphora sonchi

These blisters on sowthistle leaves are galls caused by the midge Cystiphora sonchi. They are most commonly found on Smooth Sow-thistle but may also be found on Prickly and Perennial Sow-thistle.

Photo of the association

Uroleucon sonchi

Uroleucon sonchi is a large, dark brownish aphid with a glossy shine. It is associated with Sow-thistle species.

Photo of the association

Liriomyza sonchi

The larvae of the fly Liriomyza sonchi form large upper surface blotch mines on the leaves of sow-thistle species. Secondary feeding corridors are often present. Scattered frass can be seen in the mine. Several larvae may feed together in the mine.