Lesser spearwort has distinctive scrambling, red-tinged stems which can root at leaf junctions. It is a native, perennial herb growing upright, up to 50cm, or low and spreading. The flowers are a shiny, pale yellow ranging from 7 to 20mm (less than half the width of greater spearwort). It looks like a buttercup, complete with loose sepals. However, unlike buttercups, the leaves are undivided and spear-shaped – hence its common name of spearwort. The leaves are linear and slightly toothed. It spreads by runners that root at the leaf nodes.