Invasive Plant Guide: Giant PlumelessThistle
Carduus acanthoides
Identifying characteristics
- Flower color: pink-purple
- Flowers:July to September
- Stems: partly winged; spiny. Multiple flower-heads at end of stems.
- Plant height: ranges from about 1 foot to 6 feet
- Leaves: very spiny
- Seeds:
-
Growth habit: annual/biennial
Occurrence
Open disturbed sites, roadsides, fields, pastures, hillsides, rangeland, forest openings. Prefers warm, dry climate areas. Tolerates a wide range of soil types.
Giant plumeless thistle (Carduus acanthoides) is found in only one location in the mid-Klamath. This is also the only known location in all of Siskiyou County.
Notes
Plant spreads by seed only. Seeds are viable for up to seven years, and germinate aggressively.
More Info
- California Invasive Plants Council
- http://www.cal-ipc.org/ip/management/plant_profiles/Carduus_acanthoides.php
- California Department of Food & Agriculture
- http://www.cdfa.ca.gov/phpps/ipc/weedinfo/carduus.htm
