An erect herbaceous perennial plant that produces one to several stems 0.5-3 ft in height, and has a The yellow flower heads are dandelion-like and up to 1 1/4 inches (3.2 cm) wide. The flowers are followed by seed heads with fuzzy, white seeds. The leaves have toothed or minutely prickly margins and are large, powdery green to tinged purplish, and pinnately lobed with a triangular tip. The lower leaves are stalked, while the upper leaves are sessile and clasp the stems. The stems are upright, green to purple, and branched or not.

Santa Catalina Mountains.
Sabino Canyon Recreation Area
Location: Adjacent to Sabino Creek above dam.
11/27/15

Notes: Sabino Canyon above dam 2/9/17
Per David Lazaroff : As I recall, S. asper usually appears considerably more robust, thick-stemmed, and prickly, but the clincher is the leaf bases, where they clasp the stem. Quoting An Illustrated Guide to Arizona Weeds:
S. asper - 'The middle and upper leaves are stalkless, and clasp the stem with a pair of large rounded earlike lobes.'
S. oleraceus - 'There is one consistent leaf characteristic--the pair of projections at the base of the stalkless, clasping leaves are sharp-pointed or taper to a point, and are not rounded or earlike as in spiny sowthistle.'

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