milk thistle

n 1: any of several Old World coarse prickly-leaved shrubs and

subshrubs having milky juice and yellow flowers; widely

naturalized; often noxious weeds in cultivated soil

[syn: {sow thistle}]

2: tall Old World biennial thistle with large clasping

white-blotched leaves and purple flower heads; naturalized

in California and South America [syn: {lady's thistle}, {Our

Lady's mild thistle}, {holy thistle}, {blessed thistle}, {Silybum

marianum}]