Changeable field thistle
Photo: Arne Ader
Translation: Liis
Field thistle.
Field thistle, creeping thistle |
Põldohakas
|
Cirsium arvense |
A common thistle but with an uncommonly changeable exterior. The size and shape of the plant, the appearance and thorniness of the leaves, the shape and number of thorns, the flower colour are changeable - and surely even more aspects ... All the above are mainly governed by the habitat. It prefers fertile clay soils, but grows even in the pebbles on sea shores and the plants there are really different.
Growing as a weed on arable land the plant has soft leaves and is only moderately thorny, often spines may even be absent. On the seashore plants there are many more spines, the stems can even have thorny „wings“. This is probably its original form in Estonian nature; the variety is called „needle thistle“.
The field thistle occurs on nearly all land that has been modified by humans: arable land, pastures, gardens, roadsides, waste lands, burnt areas, refuse sites ... It flowers even in September, and it is a weed that is extremely difficult to control.