Black poplar  (Populus nigra)

Anther: part of the stamen (the male reproductive organ of a flower) that produces pollen. (See http://www.rbgkew.org.uk/ksheets/pdfs/flower.pdf for a fact sheet on flower structure)
Deciduous: a plant that sheds its leaves at the end of the growing season.
Hybridisation: cross-breeding with a different species.
Stigma: the receptive part of the female reproductive organ of a flower. Pollen germinates on the stigma. (See http://www.rbgkew.org.uk/ksheets/pdfs/flower.pdf for a fact sheet on flower structure).

1. Press, B. (1992) Field Guide to the trees of Britain and Europe. New Holland (Publishers) Ltd., London.
   
2. Cheshire Wildlife Trust (April 2002):
   http://www.wildlifetrust.org.uk/cheshire/bpoplbap.htm
   
3. Coombes, A. J. (1992) Eyewitness handbooks, Trees. Dorling Kindersley, London.
   
4. WWF. Freshwater species, black poplar: flagships for floodplain forests. (April 2002):
   http://www.panda.org
   
5. Cagelli, L. & Lefevre, F. (1995) The conservation of Populus nigra L. and gene flow with cultivated poplars in Europe. Forest Genetics 2 (3): 135-144.
   http://www.tuzvo.sk/~paule/FG95/obsah23.htm
   
6. Tabbush, P. Dynamic processes in riparian ecosystems- implications for P. nigra gene conservation strategies. European forest genetic resources programme. (April 2002):
   http://www.ipgri.cgiar.org/networks/euforgen/networks/poplars/Network_ouputs/pninsitu.htm
   
7. National Biodiversity Network Species Dictionary ( July 2002)
   http://www.nhm.ac.uk/nbn
   
8. Mabey, R. (1996) Flora Britannica. Sinclair-Stevenson, London.
   
9. Milne-Redhead, E. (1990) The BSBI Black poplar survey, 1973-1988. Watsonia 18: 1-5.
   
10. Hobson, D. D. (1993) Populus nigra L. in Ireland- an indigenous species? Irish Naturalist's Journal 24: 244-247.