St. Barnaby's Thistle, Yellow star-thistle
Centaurea solstitialis
Family: Asteraceae or Compositae
What it is like
Centaurea solstitialis is a ANNUAL/BIENNIAL growing to 0.6 m (2ft). See above for USDA hardiness. It is hardy to UK zone 6. It is in flower from July to September, and the seeds ripen from September to October. The species is hermaphrodite (has both male and female organs) and is pollinated by Bees, flies, Lepidoptera (Moths & Butterflies). The plant is self-fertile. It is noted for attracting wildlife. Suitable for: light (sandy), medium (loamy) and heavy (clay) soils, prefers well-drained soil and can grow in nutritionally poor soil. Suitable pH: mildly acid, neutral and basic (mildly alkaline) soils and can grow in very alkaline soils. It cannot grow in the shade. It prefers dry or moist soil and can tolerate drought.
Height (m): 0.6
Where it is found
Cultivated land and waste ground.
S. Europe to W. Asia. Occasionally established in S. and E. England.
Conservation Status: This taxon has not yet been assessed.
Countries/locations it is found in
Argentina, Australia, Britain, Chile, Europe, France, Greece, Italy, Mediterranean, North America, South America, Spain, Tasmania, Turkey, Uruguay, USA.
How it is used
Food
Rating: 1
The plant is eaten as a vegetable. The part used is not specified.
Medicine
Rating: 1
The powdered seed is used as a remedy for stone. The powdered root is said to be a cure for fistula and gravel.
Lithontripic: Removes stones from the kidney, bladder etc.
Other
Rating: 0
Attracts Wildlife: Plants noted for attracting wildlife
How it is grown
Succeeds in ordinary garden soil. Prefers a well-drained fertile soil and a sunny position. Tolerates dry, low fertility and alkaline soils. A good bee and butterfly plant the flowers are rich in nectar. Members of this genus are rarely if ever troubled by browsing deer.
Propagating it: Seed - sow April in a cold frame. When they are large enough to handle, prick the seedlings out into individual pots and plant them out into their permanent positions in the summer. If you have sufficient seed it can be sown in situ in the spring, and an autumn swing in situ might also be worth trying.
Best place to grow: Cultivated Beds;
Habit: Annual/Biennial
Hardiness: 5-9
Growth:
Soil: Light (sandy), medium, heavy (clay)
Shade: No shade
Moisture: Dry, moist
Things to keep in mind
There is a report that the plant causes brain lesions and a nervous syndrome called 'chewing disease' in horses.
Introduced in several parts of the world, including Australia, Argentina, Chile, and the USA where it can become an invasive species and noxious weed. The plant is considered an invasive species in the US states: California, Oregon, Washington, Idaho, Utah, and New Jersey.
Its other names
Local names
St. Barnaby's Thistle, Yellow star-thistle, golden starthistle, yellow cockspur, Barnaby Thistle