The thistles provide structural and floral interest in the garden, including this one on the Systematic Beds.
Silybum marianum is an attractive biennial whose branched flower stem emerges from a basal rosette of white, mottled, and heavily veined leaves. It is this white mottling and veining which earned it the common name milk thistle. Reaching 1.5m in height, the flower stem is armed with dark green, spined leaves, while the thistle-like flower heads comprise a boss of single, purple flowers surmounted by hairless, spined bracts. One of only two species, S. marianum is a native of the Mediterranean. As is the case with many of the thistles, this is a good species for attracting bees.