spiny plumeless thistle
Carduus acanthoides L.


Carduus acanthoides is an annual or biennial herbaceous plant that grows to 5 ft. (1.5 m) tall.
This thistle may exceed two meters in height and can form weedy monotypic stands. The stem and foliage are spiny and sometimes woolly.
Flowering occurs from May to August. The flower heads are reddish-purple in color and up to 1 in. (2.5 cm) in diameter. Flower stems are branched with spiny wings extending to the flower heads.
Seeds are oblong, striate, and slightly curved.
Ecological Threat
Carduus acanthoides infests open, disturbed areas such as pastures, roadsides, and railroad right-of-ways. It can form thick stands that reduce the forage potential of pastures and suppress the growth of desirable vegetation.


Selected Images


EDDMapS Distribution

EDDMapS Distribution - This map is incomplete and is based only on current site and county level reports made by experts, herbaria, and literature. For more information, visit www.eddmaps.org

State Regulated List

State Regulated List - This map identifies those states that list this species on their regulated list. For more information, visit Invasive.org

Taxonomic Rank

Kingdom: Plantae
Phylum: Magnoliophyta
Class: Magnoliopsida
Subclass: Asteridae
Order: Asterales
Family: Asteraceae
Genus: Carduus
Subject: Carduus acanthoides L.

Synonyms and Other Names

Other Common Names:
plumeless thistle


Plants - Forbs/Herbs