Musk thistle
Encyclopedia
The Musk thistle or Nodding thistle (Carduus nutans) is a member of the sunflower family Asteraceae
. It is a biennial herb
with showy red-purple flower
s and sharply spiny stems and leaves
. It is native to much of Europe
and Asia
except for the far north.
.
The leaves
are dark green, coarsely bipinnately lobed, with a smooth, waxy surface and sharp yellow-brown to whitish spines at the tips of the lobes. They are more or less hairy on top, and wooly on the veins below.
The large globose flower heads
, containing hundreds of tiny individual flower
s, are 3–5 cm (rarely to 7 cm) diameter and occur at the tips of stems.
The flower heads commonly droop to a 90° to 120° angle from the stem when mature, hence its alternate name of "Nodding thistle". Each plant may produce thousands of straw-colored seeds adorned with plume-like bristles. They are 4 to 6 cm across, with purple-red bracts.
The stem is cottony/hairy.
Musk thistle is usually a biennial
, requiring 2 years to complete a reproductive cycle. However, it may germinate and flower in a single year in warmer climates. Seedlings may emerge at any time from spring to late summer and develop a rosette of large leaves 30–60 cm long. Plants overwinter in the rosette stage, sending up a multi-branched flowering stem in mid spring of their second year.
The number of flowerheads per plant is site-dependent and ranges from about 20-50 on good sites and 1-20 on poor sites. Flowering occurs from late spring to late summer, and seed dissemination occurs approximately one month after the flowers form. A single flower head may produce 1,200 seeds and a single plant up to 120,000 seeds, which are wind dispersed. The seeds may remain viable in the soil for over ten years, making it a difficult plant to control.
Musk thistle grows from sea level to an elevation of about 2,500 m in neutral to acidic soil
s. It typically grows on open disturbed soil or heavily grazed
land in areas such as meadows, arable land, roadsides, building sites and similar. It spreads rapidly in areas subjected to frequent natural disturbance events such as landslides and flooding, but does not grow well in excessively wet, dry or shady conditions.
in the early 19th century and has a long history there as an invasive species
. It has been declared a noxious weed
in Australia
, many U.S.
states and Canadian
provinces. Some farmers spend many hours attempting to rid them from farm ground, mostly pastures. It is equally noxious to farming operations in New Zealand.
Asteraceae
The Asteraceae or Compositae , is an exceedingly large and widespread family of vascular plants. The group has more than 22,750 currently accepted species, spread across 1620 genera and 12 subfamilies...
. It is a biennial herb
Herb
Except in botanical usage, an herb is "any plant with leaves, seeds, or flowers used for flavoring, food, medicine, or perfume" or "a part of such a plant as used in cooking"...
with showy red-purple flower
Flower
A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants . The biological function of a flower is to effect reproduction, usually by providing a mechanism for the union of sperm with eggs...
s and sharply spiny stems and leaves
Leaf
A leaf is an organ of a vascular plant, as defined in botanical terms, and in particular in plant morphology. Foliage is a mass noun that refers to leaves as a feature of plants....
. It is native to much of Europe
Europe
Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...
and Asia
Asia
Asia is the world's largest and most populous continent, located primarily in the eastern and northern hemispheres. It covers 8.7% of the Earth's total surface area and with approximately 3.879 billion people, it hosts 60% of the world's current human population...
except for the far north.
Description
Mature plants range in height from 1-1.5 m tall and have multi-branched stemsPlant stem
A stem is one of two main structural axes of a vascular plant. The stem is normally divided into nodes and internodes, the nodes hold buds which grow into one or more leaves, inflorescence , conifer cones, roots, other stems etc. The internodes distance one node from another...
.
The leaves
Leaf
A leaf is an organ of a vascular plant, as defined in botanical terms, and in particular in plant morphology. Foliage is a mass noun that refers to leaves as a feature of plants....
are dark green, coarsely bipinnately lobed, with a smooth, waxy surface and sharp yellow-brown to whitish spines at the tips of the lobes. They are more or less hairy on top, and wooly on the veins below.
The large globose flower heads
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...
, containing hundreds of tiny individual flower
Flower
A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants . The biological function of a flower is to effect reproduction, usually by providing a mechanism for the union of sperm with eggs...
s, are 3–5 cm (rarely to 7 cm) diameter and occur at the tips of stems.
The flower heads commonly droop to a 90° to 120° angle from the stem when mature, hence its alternate name of "Nodding thistle". Each plant may produce thousands of straw-colored seeds adorned with plume-like bristles. They are 4 to 6 cm across, with purple-red bracts.
The stem is cottony/hairy.
Musk thistle is usually a biennial
Biennial plant
A biennial plant is a flowering plant that takes two years to complete its biological lifecycle. In the first year the plant grows leaves, stems, and roots , then it enters a period of dormancy over the colder months. Usually the stem remains very short and the leaves are low to the ground, forming...
, requiring 2 years to complete a reproductive cycle. However, it may germinate and flower in a single year in warmer climates. Seedlings may emerge at any time from spring to late summer and develop a rosette of large leaves 30–60 cm long. Plants overwinter in the rosette stage, sending up a multi-branched flowering stem in mid spring of their second year.
The number of flowerheads per plant is site-dependent and ranges from about 20-50 on good sites and 1-20 on poor sites. Flowering occurs from late spring to late summer, and seed dissemination occurs approximately one month after the flowers form. A single flower head may produce 1,200 seeds and a single plant up to 120,000 seeds, which are wind dispersed. The seeds may remain viable in the soil for over ten years, making it a difficult plant to control.
Musk thistle grows from sea level to an elevation of about 2,500 m in neutral to acidic soil
Soil
Soil is a natural body consisting of layers of mineral constituents of variable thicknesses, which differ from the parent materials in their morphological, physical, chemical, and mineralogical characteristics...
s. It typically grows on open disturbed soil or heavily grazed
Grazing
Grazing generally describes a type of feeding, in which a herbivore feeds on plants , and also on other multicellular autotrophs...
land in areas such as meadows, arable land, roadsides, building sites and similar. It spreads rapidly in areas subjected to frequent natural disturbance events such as landslides and flooding, but does not grow well in excessively wet, dry or shady conditions.
Cultivation
Musk thistle was introduced into the eastern North AmericaNorth America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...
in the early 19th century and has a long history there as an invasive species
Invasive species
"Invasive species", or invasive exotics, is a nomenclature term and categorization phrase used for flora and fauna, and for specific restoration-preservation processes in native habitats, with several definitions....
. It has been declared a noxious weed
Weed
A weed in a general sense is a plant that is considered by the user of the term to be a nuisance, and normally applied to unwanted plants in human-controlled settings, especially farm fields and gardens, but also lawns, parks, woods, and other areas. More specifically, the term is often used to...
in Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
, many U.S.
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
states and Canadian
Canada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...
provinces. Some farmers spend many hours attempting to rid them from farm ground, mostly pastures. It is equally noxious to farming operations in New Zealand.
External links
- Jepson Manual Treatment
- USDA Plants Profile
- Photo gallery
- Species Profile- Musk Thistle (Carduus nutans), National Invasive Species Information Center, United States National Agricultural LibraryUnited States National Agricultural LibraryThe United States National Agricultural Library is one of the world's largest agricultural research libraries, and serves as a National Library of the United States and as the library of the United States Department of Agriculture...
. Lists general information and resources for Musk Thistle.