Sonchus asper
spiny sowthistle, prickly sowthistle, spiny-leaved sowthistle, prickly sowthistle, spiny-leaf sow-thistle, perennial sowthistle, achicoria dulce
Family
Asteraceae
Leaf Arrangement
alternate, basal
Leaf Attachment
clasping
Leaf Margin
entire, pinnatifid
Leaf Type
simple
Leaf Shape
lanceolate, oblanceolate, obovate, deltoid, ovate
Growth Form
forb
Flower Color
yellow
Flower Month
February - October
Height (meters)
0.3 - 2.0
Milky Sap
Yes
Armed/Unarmed
Armed
Origin
introduced
Lifespan
annual
Growing Season
Cool season
Wetland Class
FACU
Wetland Coefficient of Conservatism
0
Prairie Coefficient of Conservatism
-1
Field Characters
Plants of the genus Sonchus are often confused with Cirsium sp., or bull-thistle, probably because they are both called thistles and have spiny leaves. Sonchus is easily distinguished from look-alikes by the presence of milky sap.
Cultural Information
Seeds germinate at an optimum temperature of 95 degrees F (35 C), but germination improves at alternating temperatures of 50-75 F (10-25 C) (Lauer 1953).
Natural History
Found in disturbed ground throughout Texas. A native of Europe that is now widely naturalized.
Habitat
Roadsides, fields, pastures, disturbed ground.