Skip to main content

Sonchus oleraceus - common sowthistle

Scientific Family
Asteraceae
Other common names
annual sowthistle
Plant type
Forbs and Subshrubs
Origin
Introduced
Lifecycle
Annual
Similar species
<i>Sonchus arvensis, Sonchus asper </i>
Height
1 to 4 feet
Riparian
No
An erect fleshy annual 1 to 4 feet high. The Latin name Sonchus refers to the hollow stem, while oleraceus refers to its good taste.
Auricles of the leaves acute; achenes transversely wrinkled distinguish this plant from Sonchus asper.

Habitat

Imported from Europe, grows in vacant lots, roadsides, cultivated fields, and gardens. Generally considered invasive, it can often be controlled by mowing, because it does not regrow from root fragments.
Plant Community
Disturbed Areas
Low elevation
0
High elevation
4900

Flower Characteristics

Flowerheads are numerous and 1/4 to 3/4 inch wide. The plant will flower throughout the year. Common pollinators include bees and flies.
Flower color
Yellow
Flower shape
Daisy or dandelion-like
Tubular
Yes
First bloom month
January
Last bloom month
December
Flower clusters
Rounded

Leaf and Stem Characteristics

Tapered or wing-petioled leaves are deeply lobed on the lower portions of the plant and less so on the upper leaves. Basal leaves are stacked while the upper leaves clasp the stem. Stems are proximally branched.
Leaf type
Simple
Leaf color
Green
Leaf shape
Round or oval
Leaf margin
Lobed
Leaf attachment
Basal & Alternate
Leaves clasp
Yes
Leaf hairs
None
Spines
No

Fruit and Seed Characteristics

Fruit is flat and wrinkled on each face.
Fruit type
Achene
Fruit color
Dark brown
Seeds are ribbed and flat with a tuft of fine hairs that allow wind-blown dissemination.