Sunday, 20 February 2011

When Scurvy Came to Derby

It doesn't sound nice, does it? Scurvy in Derby? But for people like me, scurvy was of great interest when  it spread rapidly through the city streets and along the arterial roads of our county a few years ago.

Cochlearia danica Danish Scurvy Grass) and Bellis perennis (Daisy), Derby City
Danish Scurvy Grass in flower beside a solitary Daisy
at Bass' Recreation Ground, Derby. 
I'm not talking of that horrible disease caused by vitamin deficiency, of course. No, I am talking about our over-use of salt causing something unusual to spread like wild-fire, right across the country.

Thankfully, it's nothing to be afraid of - it's simply the pretty little maritime flower known as Danish Scurvy Grass (Cochlearia danica). Records collated by my team of volunteers at Derby Museum showed it was first recorded at Butterley in Derbyshire in 1972 by local naturalist, Roy Frost. This was an unusual event in itself, as Scurvy Grass normally grows close in coastal areas exposed to salt-spray from storms and high winds. The plant was not seen again until a couple of records were made in 1994. When I stumbled across a massive patch in flower alongside the A516 at Bearwardcote in 1995 its presence and sudden spread in our county was still not fully appreciated.

Having identified the plant as being a rarity (it was at the time, anyway),  I contacted our county plant recorder for confirmation. Pretty soon he responded by saying he was seeing it all along the A38 from Derby to Alfreton. In fact over the next few years it spread right across Derbyshire as part of a UK-wide spread from coastal areas.

Map plotting records at 1km accuracy.
Major roads shown in red.
The main reason for its spread was the rise of the use of salt for winter road "gritting". The salt melts the ice and later washes away, unlike true grit. But the salt contaminates the grass road verge, rendering it ideal for Danish Scurvy Grass to invade. With its tiny seeds it can spread easily, blown by the draught from passing vehicles.

I have jointly run the Flora of Derbyshire Project with Dr Alan Willmot in a voluntary capacity  since 1994, and it has been recording the spread and distribution of all plants and flowers within Derby and Derbyshire ever since. The project has the support of Derby Museums, for it was in 1969 that our museum published the previous Flora of Derbyshire. Over those years a veritable army of volunteer plant recorders and data inputters has amassed over 800,000 computerised records of which the vast majority are now online. Shown here on Derby City Council's website is the account for Danish Scurvy Grass, with its lines of distribution following just the main arterial routes through the city of Derby and out through the county. This account, and another 2000 like it are set to be included in the final published 'Flora of Derbyshire'

Its still quite unusual to find it along minor roads. As many of us experienced this winter, these minor roads rarely get gritted at all during icy weather!

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