General: Perennial herb from a creeping rhizome; stems ascending, 10-30 cm tall/long, often decumbent or creeping at the base and producing prostrate, nodally rooting branches, otherwise simple, finely and closely short-hairy, or smooth.
Leaves: Opposite, often short-stalked below, unstalked above, elliptic to broadly egg-shaped, 1-2.5 cm long, obscurely blunt-toothed to entire, smooth or nearly so.
Flowers: Inflorescence a terminal bracted raceme, at first compact then elongating and lax, of several to many (to 30) stalked flowers, the stalks finely short-hairy and often also glandular, shorter than the bracts, at least the upper bracts alternate, the lower gradually passing into leaves; corollas bright blue or pale blue to white with darker blue lines, saucer-shaped, 4-8 mm across, irregularly 4-lobed, the lobes much longer than the short tube, the upper lobe largest, the lowest lobe narrower than the others; calyces short-hairy or glandular-hairy, deeply 4-lobed, the lobes oblong to egg-shaped, 2-4 mm long, slightly unequal; styles short, 2-3.5 mm long; stamens 2, exserted, the filaments 1-4 mm long.
Fruits: Capsules, 3-4 mm long, flattened, heart-shaped, wider than long, distinctly notched at the tip, thinly glandular-hairy; seeds numerous, about 0.7 mm long.
Notes: Two varieties occur in BC
1. Axis of inflorescence and flower stalks minutely incurved-hairy, non-glandular; corollas to 5 mm wide; introduced in SW and E BC..................... var. serpyllifolia
1. Axis of inflorescence and flower stalks finely minute-hairy but also with spreading glandular hairs; corollas to 8 mm wide; native throughout BC..................... var. humifusa (Dickson) Vahl
Mesic to wet meadows, fields, streambanks, thickets, open forests and waste places in the lowland, steppe, montane and lower subalpine zones; frequent throughout BC, especially southward; var. humifusa - circumpolar, N to AK, E to NF and S to NH, NY, MI, WI, MN, NM, AZ, CA and MX; Eurasia, var. serpyllifolia - introduced from Europe.
