Thymus praecox subsp. britannicus (Ronniger) Holub

This is very near to T. serpyllum, from which it was not distinguished (as T. drucei) until 1924. It is a variable polyploid species, with the habit of T. serpyllum, differing in the obscurely four-angled stems, two of the opposite faces being hairy, the other two glabrous or almost so. Less constant differences are the slightly larger, obovate leaves and broader flower-heads. In Flora Europaea T. drucei is included in T. praecox subsp. arcticus, which, according to that work, differs from T. serpyllum in leaf-venation: the lateral veins curve along the margin, anastomosing at the apex of the leaf, while in T. serpyllum they fade away before reaching the apex. However, in the British Isles T. praecox subsp. britannicus (which is founded on British specimens) is not so clearly differentiated from T. serpyllum as its continental counterparts.T. praecox subsp. britannicus (syn. T. drucei), the British wild thyme, is much commoner in the British Isles than T. serpyllum in the narrow sense, and is the thyme of the chalk downs, always loved for its sweet scent, the ‘wild thyme’ of Shakespeare, and the ‘close cropped thyme’ of Kipling,’… that smells Like dawn in Paradise.’ T. praecox subsp. britannicus is much more variable than T. serpyllum and most of the creeping ornamental thymes treated as varieties of the latter belong to T. praecox subsp. britannicus or to other members of the T. serpyllum aggregate. But the treatment of these is beyond the scope of this work.