Musk thistle is a biennial but sometimes a winter annual that grows up to six feet tall.

• Large stem branches out towards the top with leaves that are alternate, pinnate (compound leaf with leaflets arranged on opposite sides of the axis) cleft with narrow lobes and serrated spine tipped margins.
• Inflorescence (flowering part of the plant) is a deep rose, violet or purple solitary head that tends to hang, thus the other common name, Nodding thistle.
• Have spiny bracts and produce a one fourth inch, hairy fruit called an achene (small, dry, indehiscent fruit with a single locule and single seed, with seed attached to ovary wall).
• Grows in disturbed pastures where water collects i.e. stream banks, ditches, and embankments.
• Introduced to North America in the early part of the 21 st Century, and tends to be a highly aggressive species.

Photo Credit: Pam Regensberg , USFWS

For a complete Refuge species list

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connect with the U.S. Dept Agriculture Plant Data Base

Last Updated: 2/9/09

Plants that do not grow naturally on this short grass prairie are called "invasive species."

INFORMATION from US Fish & Wildlife

ANNUAL RYE
CANADA THISTLE
CHEAT GRASS
FIELD BINDWEED
KOCHIA
COMMON MULLEIN
MUSK THISTLE
RUSSIAN KNAPWEED
RUSSIAN OLIVE
RUSSIAN THISTLE

VOLUNTEER WEED MAPPING
PROGRAM