Subject: The Motorway Plant

From: [email-masked] (archmain)
Date: 3 Apr 1995 20:54:08 GMT

From: [email-masked] (archmain)
Newsgroups: bionet.plants
Subject: The Motorway Plant - Danish Scurvy-grass
Organization: None
X-Newsreader: WinVN 0.92.1

I would like to hear from anyone who feels they
have an explanation as to why Danish Scurvy-grass,
Cochlearia danica, grows along the central reservation
of motorways (freeways) here in Britain, but not on the
sides. 

It is in flower at the moment and, in some places,
looks like frost or a sprinkling of snow.  It grows quite
thickly and often in stretches many metres long.  There
are no plants, however, on the sides of the road in what
appear to be identical conditions.

The plant used to be more or less confined to shingle
beaches until motorways came along and is spreading 
rapidly along central reservations in south east England.  
Some have surmised that salt from the winter gets 
distributed more to the centre than the edges of the road 
and that this favours what is essentially a seaside plant.  
This seems highly improbable to me.  I believe the plant 
has a predator, maybe several, which will approach the 
edges of the road and eat leaves or seeds, but dare not 
venture into the central reservation.  It is probably diurnal 
(maybe a bird) and therefore not active at night when the 
motorways are quiet.  However there may be other 
theories ....

--
Patrick Roper