I can assure you that, although in Britain there is a problem with the
introduced spanish bluebell, the native ones are by no means rare. Of
course, this may not be the case world-wide.

Regarding the wider question, although I appreciate that species do
interbreed, isn't the fact that they can't one of the things that make them
species? whoops, not good English I mean, shouldn't we restrict the
artificial term 'species' to organisms which can only breed within that
species?

And, on a tangent, shouldn't we use the word specie for one species (not
that I do)?

--
David Brear

Conserv@tion
http://www.habitat.org.uk/news1.htm

The Wild Flower Page
http://www.habitat.org.uk/wildflwr.htm
"David Hershey" wrote in message
om...

If breeding between two species occurs at a high frequency, it may
result in extinction of one parent even if the hybrids are infertile
(Levin 2002). This can happen naturally but more frequently occurs
when one species is introduced. For example the English bluebell
(Hyacinthoides non-scriptus) [synonyms: Scilla non-scripta, Endymion
non-scripta] readily crosses with the introduced and larger, more
vigorous Spanish bluebell (Hyacinthoides hispanica) to form hybrids.
Hyacinthoides non-scriptus has become rare in the wild as the hybrids
have crowded it out. Levin (2002) gives other examples of introduced
plants that may eventually cause extinction of native species, such as
cultivated sunflowers (Helianthus annuus) breeding with wild
sunflowers to produce fertile hybrids.