Worcestershire Record No. 21 April 2007 pp. 47-48


Harry Green

While hoeing my vegetable patch last summer (2006) I noticed thin yellow strands winding through a weed patch. I thought, that looks like dodder, surely not! But it was – though not a native species. In addition various other “odd plants” were appearing some distance from the bird feeding station (where sunflowers and Ragweed often germinate from seed fed to wild birds) so I called in a proper botanist – Bert Reid. Having collected samples he produced the following list of foreigners – the dodder originates from North America.

Abutilon theophrasti  Velvetleaf SE Europe
Amaranthus hybridus Green amaranth America
Ambrosia artemisiifolia Ragweed N America
Cuscuta campestris Yellow dodder N America
Datura stramonium Thorn-apple America
Echinochloa crusgalli Cockspur grass Tropics
Fagopyrum esculentum Buckwheat Asia
Guizotia abyssinica Niger East Africa
Helianthus petiolaris Lesser sunflower N America
Panicum miliaceum Common millet Asia

Table shows Bird food aliens and their place of origin.

Over the last ten years birds in my garden have been fed with vast quantities of black sunflower seed. I compost the abundance of husks from the seed – it makes very good compost! This is recycled through the vegetable patch and obviously many contaminant seeds are eventually germinating. When I called in Bert Reid I had quite forgotten a paper by Hanson & Mason (1985) which reported an investigation into contaminants of imported seed used to feed caged birds. The authors set out to germinate seeds from bird food and produced a list of 438 species from around the world believed to imported in this way. Of these about 30 species had regularly been recorded from waste ground and rubbish tips. Since 1985 a vast industry has developed to supply garden bird food, including imported seeds. It is therefore not surprising that “strange plants” are appearing in gardens and other places. Nowadays climate change may encourage some of these to produce seeds and become regular residents. So if you feed the birds in your garden it is well worth keeping a lookout for unusual plants and calling in a botanist. We are always glad to receive new records.


HANSON, C G & MASON, J L. 1985. Bird seed aliens in Britain. Watsonia 15: 237-252.
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