Stem. - Erect. Leaves. - Divided into three delicate clover-like leaflets. Flowers. - Golden-yellow. Calyx. - Of five sepals. Corolla. - Of five petals. Stamens. - Ten. Pistil. - One, with five styles.

All summer the small flowers of the yellow wood sorrel show brightly against their background of delicate leaves. The plant varies greatly in its height and manner of growth, flourishing abundantly along the roadsides. The small leaflets are open to the genial influence of sun and air during the hours of daylight, but at night they protect themselves from chill by folding one against another.