Alcohol, algorithm, algebra, alcove, alkanet; these are several words used in English that start with ‘al’ coming from Arabic for the word ‘the’.

But why should the British native plant, green alkanet, have an Arabic name? This is because the plant was not named by botanists but by merchants trading in dyes. Someone heard an Arab merchant calling a product ‘al henna’ and thought he was saying ‘al kanet’. Henna is the dark red dye that comes from Egyptian privet and the roots of green alkanet give a similar dye. Egyptian henna would come as a dried brown powder while green alkanet would come from freshly dug roots, in the green.

As alkanet is found near sites of former monasteries it may have been introduced by monks in the middle ages. It is a native of Western Europe and probably was a native of South West England from where it spread throughout Britain. It now grows as far north as Fife.

Alkanet is a bristly perennial; the flower has five petals of deep blue. It is a good nectar flower for all kinds of bees. It used to be a popular garden plant, but it is now out of fashion as it can become invasive; but it can still be bought. In the past it was widely used as a dye for textiles and leather. It was a food colourant used in medicines and in the wine trade, also as a cosmetic to colour lips. It is still used as a dye for violins applied before the varnish and is sold worldwide.

Alkanet is a fussy plant and is absent from many places in Britain but grows in profusion on old lime mortar and is most happy near old buildings and where builder’s rubble has been dumped. It flowers from April till early summer then dies back completely, not putting up green shoots again until winter comes. It will spread by seed but multiplies best when its roots are disturbed, and is quite happy to have its roots harvested for dye. In Sidmouth, to see a sight almost as spectacular as a bluebell wood, walk through The Byes to the Bramble Bank by the Lawn Vista steps to see the vibrant blue flowering of green alkanet.