Text Box: Danish Scurvygrass comes to Milton Keynes

By Roy Maycock

 

 

Several species of maritime plant have been seen growing by inland roads since about 1970 but it is only recently (about 15 years) that their spread has been so spectacular.  At first records came from close to the coast and on main dual-carriageways and motorways but their spread continues and, not always, on such main roads.  Surrey, West Kent and East Anglia had some of the first records for Danish Scurvygrass and, by 1985; it had been seen 75km inland on the A45.  By July 1990 there were records from 182 inland hectads (10km x 10km grid squares) – their pattern on a map making interesting viewing of the then motorway route!  However, over 250 other hectads had also been driven through, but no plants seen.  Between 1990 and 2000 the number of hectads with the scurvygrass had increased to 695!

 

I first saw Danish Scurvygrass on the central reservation of the A40 at its junction with the A418 from Thame.  Such a situation was like so many of the early records – but why there?  As winter approaches temperatures drop and ice and snow may become hazardous on roads.  The solution?  Put salt on them!  Doubtless it is this salt which provides the right conditions for maritime plants and the sand and gravel used in the construction of the central reservations may have been the source of the seed.  Evidence in the 1980s suggested so.  However, since then the plant has ventured beyond central reservations and is now frequent on roadsides, be they single-or dual carriageways.  For example, leaving the aforementioned A40 and going on to the A418 towards Thame there are now many miles of Danish Scurvygrass on both sides of the road.

 

Danish Scurvygrass is a low-growing, annual herb with small, rounded or rounded-triangular shaped leaves in a basal rosette at flowering time.  The short flowering shoots arise from the rosette, have a few leaves and many small flowers crowded at the top.  The petals may be white but, what makes them so conspicuous, is their normal lilac tinge, emphasize by their large numbers.  In Milton Keynes, the plants grow in rows right on the edge of the road i.e. within 10cm of the kerb.  They flower from about mid April to early May, so they are not overshadowed by other vegetation.  Very easy to see!

 

Once established on a roadside, the plants survive and, from the early colonisers, many more are produced and continue to spread.  In Buckinghamshire the first records were from the M4 and M40 in the south.  The spread northwards was slow but there are a few records from the Aylesbury area in the 1990s.  However, in 2004 there were many Text Box: sightings in North Bucks (as well as the south) e.g.

                   A413 north of Winslow on the bridge over the Claydon Brook

                   A421 east of Buckingham near the old road and also nearer to Thornborough.

 

My first sightings in Milton Keynes were on 21 April, just south of the Giffard Park roundabout on the V10 (Brickhill Street).  Once alerted, a lookout was kept and further sightings were made:

                   V4 (Watling Street) near The Bowl, by the road to Knowlhill and that to the Harvester Inn at Loughton.

                   V7 (Saxon Street) on the slip road to the Shell garage in Bletchley.

 

Off the grid roads plants were seen on the Stony Stratford bypass, opposite the Hanson Environmental Study Centre and the south and east Newport Pagnell bypasses with those furthest north being on the slip roads to Emberton Country Park.

 

Plants of the Danish Scurvygrass are so conspicuous a feature of roadsides when in flower that it does not seem likely that they have previously been missed in Milton Keynes.  So, what was different about 2004?  There had been salted roads in the past but obviously no seeds.  Contact with Sandy Dickinson at Milton Keynes Council may have helped to solve the mystery but this can only be speculation.  During this year some of the salt applied to the roads was purchased from Buckinghamshire County Council.  Did that salt contain seeds (remember, other County roads already had the scurvygrass)?  This does not really seem likely – unless it had been mixed with sand and/or gravel which did contain seed.  Contact with the County Council has not yet proved very helpful as to its source of salt (or the seeds!) – but the matter will be followed up.

 

Next year it will be important for as many pairs of eyes as possible to be on the lookout for Danish Scurvygrass on Milton Keynes roadsides.  Start looking in the middle of April – on the grid roads first, then elsewhere.  Does it grow on the H roads?  I didn’t see any in 2004!

 

 

 

References:

Dalby, D.H. (1991) in BSBI Crucifers Handbook

Leach, S.J. (1990) in BSBI News 55

Preston, C.D. et al (2000) New Atlas of the British and Irish Flora

Scott, N.E. (1995) Watsonia 15

 

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