Thymus serpyllum, known by the common names of Breckland thyme, Breckland wild thyme, wild thyme, creeping thyme, or elfin thyme, is a species of flowering plant in the mint family Lamiaceae, native to most of Europe and North Africa. It is a low, usually prostrate subshrub growing to 2 cm (1 in) tall with creeping stems up to 10 cm (4 in) long. The oval evergreen leaves are 3–8 mm long. The strongly scented flowers are either lilac, pink-purple, magenta, or a rare white, all 4–6 mm long and produced in clusters. The hardy plant tolerates some pedestrian traffic and produces odors ranging from heavily herbal to lightly lemon, depending on the variety.

The common blue butterfly or European common blue is a butterfly in the family Lycaenidae and subfamily Polyommatinae. The butterfly is found throughout the Palearctic and has been introduced to North America. Butterflies in the Polyommatinae are collectively called blues, from the coloring of the wings. Common blue males usually have wings that are blue above with a black-brown border and a white fringe. The females are usually brown above with a blue dusting and orange spots.