Sonchus tenerrimus Schur
Family: Asteraceae
Slender Sow-Thistle
Sonchus tenerrimus image
Luigi Rignanese  

Annual, biennials, or perennials, 10-80 cm. Stem bases soft to hard, herbaceous, often hollow. Leaves: blades of mid cauline oblong, 3-20 × 2-6 cm, bases auriculate, auricles ovate to lanceolate or linear, ± straight, obtuse to acute, margins usually pinnately lobed, lobes ± rhombic to lanceolate (constricted at bases) or ± linear, terminals ± equaling laterals, entire or dentate. Peduncles usually setose- to stipitate-glandular, often tomentose as well, sometimes glabrous. Involucres 10-12+ mm. Phyllaries usually setose- to stipitate-glandular, sometimes tomentose as well. Corollas: ligules longer than tubes. Cypselae reddish brown, oblanceoloid, 2.5-3.5 mm, ribs 1-3 on each face, faces transversely rugulose or tuberculate across and between ribs; pappi 5-8 mm. 2n = 14.

Flowering Mar-Jun. Disturbed sites, often on ballast; 0-200 m; introduced; Calif.; s Europe, w Asia, n Africa.

Sonchus tenerrimus was known historically on ballast from Alabama, Pennsylvania (Philadelphia), New Jersey, New York, and, possibly, Quebec.

Sonchus tenerrimus image
Luigi Rignanese  
Sonchus tenerrimus image
Luigi Rignanese  
Sonchus tenerrimus image
Luigi Rignanese  
Sonchus tenerrimus image
Luigi Rignanese  
Sonchus tenerrimus image
Luigi Rignanese  
Sonchus tenerrimus image
Luigi Rignanese  
Sonchus tenerrimus image
Luigi Rignanese  
Sonchus tenerrimus image
Luigi Rignanese  
Sonchus tenerrimus image
Valter Jacinto