Family, Geranium. Sepals, petals, styles, 5. Stamens, 10. Pods, long, erect, weak-stemmed, arranged in cymes or umbels, standing erect at the tip of the peduncle. Leaves, on stem and from the root, notched, of 3 leaflets.

Lady's sorrel, yellow wood sorrel. (Oxalis corniculata)

Lady's sorrel, yellow wood sorrel. (Oxalis corniculata)

The common yellow sorrel flower varies greatly in size from a buttercup to a small cinquefoil. The plant is smooth or roughish. Stem-leaves and upright pods contain acid juice, pleasing to pickle-loving school girls. The flowers grow on leafy stems, springing from the leaf-axils, on rather long peduncles. This is one of the plants that conspicuously "sleep" and fold their leaflets at the approach of night. This species bears secondary blossoms, which are pollinated in the closed bud and are especially fruitful. Strangely, the ordinary, more showy flowers absolutely prevent self-pollination by having stamens and anthers of 2 or even 3 different lengths, dimorphous or trimorphous. (See illustration, p. 182.)