This plant is the second of two subspecies (ssp hederifolia and ssp lucorum) of this early flowering annual Speedwell. There are distinguishing characteristics connected with leaf size, shape and length of pedicel (flower stalk) but the most reliable feature used to separate the two is the colour of the undehisced anthers (pollen not yet released) which should be blue in ssp hederifolia and white or very pale blue in ssp lucorum. Both species have the distinct cilia (thick hair like structures) round the edges of the sepals but there are supposed to be fewer in ssp hederifolia.