Every Wednesday, I hope to find a new ‘weed’ to investigate. My only criterion will be that I will not have deliberately planted the subject of our inquiry. Who knows what we will find…..

Dear Readers, the brassica or cruciform family of plants is a tricky one for the novice botanist. All those different rockets and cresses and mustards always make me scratch my head and run for help. So, when I found this week’s plant growing on a patch of disturbed ground by the edge of Coldfall Wood, I wondered about getting the identity correct. Fortunately our weed this week, Hoary Mustard, can be distinguished from its many relatives by having seed pods which some people compare to clothes pegs in shape, but which remind me of old-fashioned fountain pens. This has given the plant one of its alternative common names, Short-pod Mustard.

At this time of year the plant is a mass of long, wiry stems, each with a cluster of the typical four-petalled flowers on the top.

Like all of the cabbage family, the leaves are edible, and taste a little like rocket. They can also be used as a spinach substitute. It’s also one of the many plants that are used in Greek to make Horta, a cooked vegetable dish familiar to anyone who’s spent too much time sitting outside a taverna with a glass of ouzo.

Hoary Mustard was first recorded in the wild in 1837 (it comes originally from the Mediterranean) but in recent years it has been spreading from its heartland in London, and can now be found around the Severn Estuary, in East Anglia and in north west of England. It’s currently absent from Scotland and most of Ireland.

The word ‘Hoary’ probably refers to the grey-green colour of the foliage – this property is also picked up in the species name, ‘incana’, which is the Latin word for ‘grey’. In Australia, where it’s considered to be a noxious weed, the plant is known as Buchan Weed, probably because it grows in abundance along the banks of the Buchan river in Victoria.

The plant is also occasionally the larval foodplant of the Orange-tip Butterfly, who generally prefers to lay her eggs upon Garlic Mustard, but will manage with other plants if her favourite is not about.

So, here we have Hoary Mustard, another one of those leggy yellow-flowered plants that pop up as soon as the ground is dug up, and which go about their business largely unremarked. And yet, these plants are the closely relatives of so many of our foodplants – broccoli and cabbage, rocket and turnip, radish and even that superfood of the moment, kale. For the  foods with a devilish hint of sulphur, or a tang of pepperiness, I give thanks to the wild brassicas, the plants that started it all.