- Name also: Bugleherb, Creeping Bugleweed, Carpetweed, Carpet Bugle, Carpet Bugleweed, Common Bugle, Common Bugleweed
- Family: Mint Family – Lamiaceae (Labiatae)
- Growing form: Perennial herb.
- Height: 10–35 cm (4–14 in.). Stem erect, 4-edged, hairy on opposite sides. Ground runners up to 50 cm (20 in.) long.
- Flower: Irregular (zygomorphic). Corolla blue, bilabiate, 14–17 mm (0.55–0.7 in.) long. Upper lip short, entire and flat. Lower lip 3-lobed, central lobe with notched tip. Calyx 5-toothed, almost regular (actinomorphic). Stamens 4 attached to upper part of corolla tube, of which 2 long, 2 short, stamens longer than corolla. United gynoecium comprised of 2 carpellary leaves. Ovary above perianth. Flowers in whorls in a long raceme.
- Leaves: Decussate. Rosette leaf blade elliptic or ovate, round-tipped, big- and with shallowly rounded teeth, virtually glabrous, short-haired. Subtending bracts noticeably smaller than rosette leaves, become smaller towards crown. Uppermost leaves shorter than flowers, often partly blue.
- Fruit: Schizocarp comprised of 4 carpels, carpel like an achene.
- Habitat: Rich forests, ruins, yards, fields, meadows and roadsides, also ballast soil deposits.
- Flowering time: May–July.
The scientific name of plants sometimes changes as more detailed studies lead them to be classified in a different way, and blue bugle’s Finnish name has also changed over the years. The name of the genus, Ajuga, refers to its use as a medicinal. Blue bugle’s aerial parts have been used to strengthen the organs, soothe the mucous membrane and treat wounds.
Blue bugle, and especially its varieties which have red and variegated leaves, (e.g. Atropurpurea), are cultivated as ornamentals. They thrive so well in Finland that they can escape into the wild and survive in old gardens for decades. A. pyramidalis x reptans is a hybrid between blue bugle and the rarer pyramidal bugle (A. pyramidalis) that grows occasionally in the province of Uusimaa, in which Helsinki is located, and in the Varsinais-Suomi region in the south-west of the country.