Stems are glabrous, simple or little branched.
Plant flowers from June through September. It grows mainly in Mediterranean region where it is a wayside herb of uncultivated ground and waste places. It is naturalized and a weed in the Eastern United States, California and South America. S. marianum has a stem 20-150 cm high, rarely shorter, glabrous or slightly downy, erect and branched in the upper part. The leaves are alternate, large, white-veined, glabrous with strongly spiny margin.