Reproducing by seed and by spreading underground rhizomes and rooting stems.
Stems 10-30cm high, somewhat fleshy (Fig 3), very finely hairy. Plants tufted with spreading branches which soon curve upwards into erect stems (Fig 4), or with horizontal stems rooting at nodes (a) touching the ground and producing short erect branches, or occasionally just single erect stems from underground rhizomes.
Leaves (Fig 6) on horizontal stems (b) and lower parts of erect stems (c), opposite (2 per node), oval to roundish or broadly ovate, lacking teeth or with very fine teeth, stalkless, with 3 to 5 main veins arising from the base of the leaf, the side veins curving in towards the tip; on the upper parts of the stems the leaves (d) (or flower bracts) with flowers in their axils (angle between leaf and stem) are usually alternate (1 per node) and smaller than the lower opposite leaves.
Flowerstalk (e) usually shorter than its leafy bract (d) ; sepals 4, small; corolla flat with 4 lobes (Fig 5), pale bluish-white with blue lines or bright blue; stamens 2; seedpods (f) flat, appearing soon after the blossom falls, deeply notched at the tip, appearing 2-lobed, 4-8mm. wide, broader than long. Flowers from late spring until late autumn.
Thyme-leaved speedwell occurs throughout Ontario in waste places, pastures, roadsides, meadows and lawns. There are at least eight different kinds of speedwell in Ontario and identification may be difficult.
It is distinguished by its perennial habit, lower leaves opposite, somewhat roundish and lacking teeth or with very fine teeth, its short-stalked (e) flowers with white or bluish 4-lobed corolla, its flowers stalk usually shorter than the leafy bract (d) just below it, and its seedpod notched at the end (Fig 4).
(A) Plant. (B) Flower. (C) Seedpod.
Thyme-leaved speedwell plant.
Flower bract of thyme-leaved speedwell with notched seedpod.
Flower of thyme-leaved speedwell, July in Southern Ontario.
Opposite leaves of thyme-leaved speedwell.