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Blessed Milkthistle

Silybum marianum

Milk Thistle, Silybum marianum, photo © by Michael Plagens

Photographed in a weed-choked lawn in Glendale, Arizona. April 2009.

Asteraceae -- Sunflower Family

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RANGE: Because of reputed medicinal uses this plant has been cultivated in many places around the World. It is thus an escape from its origin in southern Europe. In the Sonoran Desert generally restricted to urban and agricultural areas.

LEAVES: The coursely dentate leaves with spiny margins are often blotched with white - looking like spilled milk almost.

ANNUAL: In milder climates this herbaceous plant may grow two years as a biennial. Normally about knee-high, but occasionally much larger.

FLOWERS: Disc florets only. These flowers are long tubular and purplish-pink in color. The roundish heads are enclosed by spiny bracts. In our Sonoran Desert blooming is mostly in late spring.

ACHENE: Seeds are broadly oval with a ring of fine, barbed bristles at top.

ARMED Sharp spines on flowers heads and leaves.


Copyright Michael J. Plagens, 1999-2010