Carduus acanthoides
Encyclopedia
Carduus acanthoides is a species of thistle
known as the spiny plumeless thistle and welted thistle. This plant is native to Europe but is well-known in many other parts of the world, including parts of North and South America, New Zealand, and Australia, as a noxious weed. This thistle may exceed two meters in height and can form weedy monotypic stands. The stem and foliage are spiny and sometimes woolly. The plant starts from a flat basal rosette and then bolts an erect stem with occasional toothed, wrinkled, spiny leaves. At the top of each branch of the stem is an inflorescence
of one to several flower heads
, each rounded, covered in spiny phyllaries
, and bearing many threadlike purple disc florets. In both native and non-native ranges this plant is a weed of roadsides, fields, and disturbed areas.
Thistle
Thistle is the common name of a group of flowering plants characterised by leaves with sharp prickles on the margins, mostly in the family Asteraceae. Prickles often occur all over the plant – on surfaces such as those of the stem and flat parts of leaves. These are an adaptation that protects the...
known as the spiny plumeless thistle and welted thistle. This plant is native to Europe but is well-known in many other parts of the world, including parts of North and South America, New Zealand, and Australia, as a noxious weed. This thistle may exceed two meters in height and can form weedy monotypic stands. The stem and foliage are spiny and sometimes woolly. The plant starts from a flat basal rosette and then bolts an erect stem with occasional toothed, wrinkled, spiny leaves. At the top of each branch of the stem is an inflorescence
Inflorescence
An inflorescence is a group or cluster of flowers arranged on a stem that is composed of a main branch or a complicated arrangement of branches. Strictly, it is the part of the shoot of seed plants where flowers are formed and which is accordingly modified...
of one to several flower heads
Head (botany)
The capitulum is considered the most derived form of inflorescence. Flower heads found outside Asteraceae show lesser degrees of specialization....
, each rounded, covered in spiny phyllaries
Bract
In botany, a bract is a modified or specialized leaf, especially one associated with a reproductive structure such as a flower, inflorescence axis, or cone scale. Bracts are often different from foliage leaves. They may be smaller, larger, or of a different color, shape, or texture...
, and bearing many threadlike purple disc florets. In both native and non-native ranges this plant is a weed of roadsides, fields, and disturbed areas.