The flower of the common Teasel above and below. These are the seed heads and they should be removed before the seeding stage otherwise you will end up with hundreds of them around the main plant and everywhere else. If they have already seeded these should be visible within a few weeks, they can be removed fairly easily or moved to a more suitable site. Despite the seeding thuggery the seed heads will attract Goldfinches into your garden (of course if you haven't removed them) Once finished the plant will die off and should be either removed or can be left over winter as the seed heads look beautiful in the winter frosts.
Below the foliage of the Teasel which is quite spiny and care must be taken when handling as it will cause pain. During this phase of the plants growth some leaves will naturally brown and will need to be removed ( Gloves are advised ) As teasels are biennials the first year will be growth of the leaves only, if you wish to move the plant this is the time to do it in the Autumn. The flower spike will come in the second year.