Lapsana communis L.
Nipplewort is native to Europe, from Britain and Scandinavia to North Africa and western and central Asia.
Identification: Plants are 6-60" (15-152 cm) in height, either hairy or hairless. A stiff major stem is often reddish and somewhat ridged. Leaves are oval or round, ⅜-6" (1-15 cm) × ⅜-2½" (1-7 cm). Each leaf has a large roughly triangular (deltate) lobe at the end, often with two smaller side lobes at the base that vaguely resemble nipples, hence the common name. Lower leaves also have a long petiole that is slightly winged and hairy. They flower from April to September. Flowers occur in panicles of 5-25, rarely as high as 100, each flower ¼-½" (6.3-12 mm) across, with 18-20 pale yellow rays. Though similar in appearance to hawkweed flowers, they are somewhat paler and, instead of dense dandelion-like centers, the centers look significantly different.
Nipplewort looks superficially similar to hawkweeds. See this hawkweed comparison table for details.
Medical: The milky latex exuded from cut stems and leaves is said to be soothing to the skin, specifically to nipples of nursing mothers.
Lapsana communis at Illinois Wildflowers
Lapsana communis on Forest and Kim Starr’s Starr Environmental site
Lapsana communis at the University of Wisconsin's Robert W. Freckmann Herbarium
Lapsana communis on Plants for a Future, a resource and information centre for edible and otherwise useful plants
Lapsana communis on inside.ewu.edu
Lapsana communis from the Jepson Manual
Lapsana communis on eFloras
Lapsana communis description by Thomas H. Kent, last updated 25 May 2020.