Perennial Sow thistles (Sonchus spp.)



Copyright © 1995-2003 Henriette Kress.

Scientific Names: Sonchus arvensis


Picture Thanks to:  Henriette Kress.

Appearance:  Tall, bluish-green with milky juice.  The leaves are usually prickly edged with the bases clasping the stem.  The flower heads are yellow with ray florets only, forming branched clusters in July through October.  The fruits are slightly flattened, ribbed seed-like achenes (- a small, dry fruit with one seed) each with tips of a tuft of white, hair-like bristles.  Different from the Prickly sow thistle S. asper and the Annual sow thistle S. oleraceus, the Perennial sow thistle S. arvenis has deep, creeping rootstocks, 3-5 cm wide flower heads and glandular-hairy involucral bracts (- “involucral -A series of bracts beneath or around a flower or flower cluster; - bract - a modified leaf or leaf-like part just below and protecting an inflorescence”. ( ). 



Habitat:  Introduced from Europe, but grow on disturbed sites from BC and Alberta to New Mexico.


Collecting:  Young leaves can be added to salads or cooked as a hot vegetable with butter, seasonings, or vinegar, or as a pot herb.  Sometimes Sow thistles are added directly to curries and rice dishes, but they are usually quite bitter and require at least 1 change of water.  Older leaves are bitter and tough.


Medicinal uses for asthma:  The Perennial sow thistle has been used to calm nerves and treating in asthma, bronchitis and coughs.