‘It is rocket science,’ said my husband waving a pinnately lobed leaf snatched from his restaurant salad. He doesn’t much like rocket salad and wishes all supplies had perished along with the lettuces of Spain. So as a distraction I tried telling him that rocket leaves were connected with street urchins, caterpillars, caprices and hedgehogs.
The herb rocket is older in English than the sky-rocket, which appeared no earlier than 1566. The firework rocket took its name from rocchetta in Italian, meaning ‘little bobbin’, from the similarity in shape. There is a related old word in English, rock, which once meant ‘distaff’ and is used by historians now to mean ‘spindle’. But that is nothing to do with the greenery. Salad rocket is related in origin to the Italian rucola, by which we have also learnt to call it. The Italian word from which we took rocket in the 16th century was ruchetta. This was a diminutive of ruca, borrowed from the Latin eruca — some kind of cabbage. The Americans sometimes call rocket arugula, a regional Italian variant of rucola.
The Latin word eruca also meant ‘caterpillar’. It was used in the English of the Douay version of the Bible (1610) with that meaning. The English urchin, meaning ‘hedgehog’, is derived via French from the Latin ericius, said by philologists to be related to eruca. In medieval English Bibles the form yrchoun or urchuon was used for ‘hedgehog’. A 15th-century cookery book recommends sticking almonds into pork to make it bristle like a hedgehog or yrchon — I might try it. The French form hérisson meant a spiked revolving beam as part of a fortification.