Some listings have now been removed, original screen grabs below.

Ebay.co.uk:

• A seller in Yorkshire selling bags of 20 floating pennywort strands (Hydrocotyle ranunculoides).
• An Australian seller offering to ship water fern (Azolla filiculoides) anywhere in the world, including the UK.
• One Polish vendor who has sold 53 clumps of parrot’s feather (Myriophyllum aquaticum), a water plant. The advertised shipping region was “worldwide”.

Ebay.it:

• The same plant on offer in Germany to anywhere in the EU. This advertisement notes customs restrictions outside the EU, but not in the UK.

Amazon.co.uk:

• Latvian seller advertising sale of parrot’s feather into UK.
• UK seller advertising parrot’s feather (currently unavailable) for sale from warehouse in England.

The relevant UK legislation is the Wildlife and Conservation Act 1981, Section 14AZ.