Plants 1–4 dm, ± erect, rhizomatous but without stolons; stems ± villous all around, varying to subglabrous; lvs wavy-toothed or subentire, the basal ones commonly soon deciduous, the lower cauline mostly 3–7 × 1–3 cm, elliptic to obovate and tapering to a narrow or petiolar base, the upper generally broad-based and sessile, passing into the obovate bracts of the usually somewhat arachnoid-villous infl, this thyrsoid-spicate, its well developed bracts often suffused with blue; verticils 6–many-fld; cor bright blue (pink or white), 12–20 mm, the upper lip very short and minutely 2-toothed, the lower lip 5–8 mm; stamens exserted; filaments hairy; 2n=32. Native of Eurasia, escaped into lawns, gardens, and roadsides in our range. Apr.–June. Hybridizes with no. 2 [Ajuga reptans L.].
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