Danish Scurvygrass (Cochlearia danica) is a small herb with rather succulent heart-shaped leaves and tiny white flowers and its natural habitat is on steep slopes and cliffs by the sea.
In 1853 George Johnston, in the Botany of the Eastern Borders, recorded only one Berwickshire locality for Danish Scurvygrass on sea banks between Dowlaw and Redheugh.
Its sister species, Common Scurvygrass (Cochlearia officinalis), was then, and still is, abundant all along the Berwickshire coast.
However, Danish Scurvygrass, along with several other seaside plants such as Lesser Sea-spurrey, has made a dramatic spread away from the coast.
In 1997 it was first found along the A1 trunk road but since about 2000 it has rapidly spread and is now abundant along the A68 in the west of the county.
It grows on the verges close to the tarmac where plants get regularly sprayed with salty water in winter, and in places it forms a pure carpet conspicuous by its white flowers. It has been suggested that one source could have been the causeway on Holy Island from where seeds could have hitch-hiked a free ride on car tyres.
Scurvy grass is so-called because it is rich in vitamin C and was carried by sailors on long sea voyages to prevent scurvy, which is caused by vitamin C deficiency.
Plants were dried and taken on board in bundles, and because of the very bitter taste it was often heavily spiced. Nowadays citrus fruits are an important source of vitamin C but before these become widely available scurvy grass was also eaten on land.
Plants which live close to the sea or in salt deserts are called halophytes, as they are able to tolerate high levels of salt.
In some arid countries salt gradually accumulates in the soil through evaporation and can result in soils that can no longer sustain crops - they literally become salt deserts.
The same effect applies to roadside verges, where most plants cannot tolerate the increased concentration of salt caused by winter gritting, and salt-tolerant plants gain a big advantage.
This is an example of how quickly some plants can adapt to man-made changes in the environment and move into new habitats unexpectedly.
One consequence is that our roadside verges are losing some of the familiar plants such as Cow Parsley and Red Campion to these salt-loving species.
Salt can also be very damaging to our hedgerows, particularly hawthorn, and along main roads many hedges are dying or have big gaps due to salt spray.
The SWT are holding a summer field meeting on Sunday, May 24, meeting at 2pm at Cocklawburn Beach NU031481.
Cocklawburn is signposted on the A1167 between the A1 and Berwick.
Stout footwear required.
Further details from Ron McBeath 01289308515.