Seasonal Wild Flowers

Prickly Sow-thistle

Sonchus asper

Asteraceae

Rough Sow-thistle

March to November and all year during mild winters.

It is found throughout the country

See the BSBI distribution map for Prickly Sow-thistle

Prickly Sow-thistle grows in waste ground, brownfield sites,

waste tips, by railway lines, roads, pathways and arable

fields, and in gardens and rough grassland.

It is an overwintering annualm native herb, which can

grow up to 2m, although it is very variable and is usually

much shorter.

Flowers are in clusters and a slightly deeper yellow than

The leaves are usually more prickly than Smooth Sow-

Smooth Sow-thistle and Prickly Sow-thistle are quite

difficult to distinguish. The main difference is in the way

the leaves attach to the stem.

Prickly Sow-thistle has the rounded leaf auricles shown in

pictures 4 and 5, compared to the more pointed auricles of

Smooth Sow-thistle (picture 6).

Prickly Sow-thistle

Flower-head

Lower leaves and stem

Side view of rounded leaf auricles

Leaf insertion - front view

Left - Prickly Sow-thistle cf Right - Smooth Sow-thistle