l82 FLOWERS OF FIELD, HILL, AND SWAMP 



on spreading stems about a foot high, hairy, clammy. Upper 

 leaves, thin bracts. 

 May to July. 



i6. High Mallow 



Malva sylvestris. — Family, Mallow. Color, purplish or 

 pink. Leaves, sharply 5- to 7-lobed. Time, summer. 



Calyx, of 5 sepals. Underlying is a 3-leaved involucel, like 

 a second calyx. Corolla, of 5 petals, large, notched. Sta- 

 mens, united, their anthers kidney-shaped. Styles, numerous, 

 making a ring of blunt, roundish, wrinkled, veiny, one-sided 

 carpels when ripe. Stem, 2 to 3 feet liigh. 



Imported from Europe; not an uncommon wayside plant. 



17. Lady's-sorrel. Yellow Wood- sorrel 



Oxalis cornicu/ata, var. strida (from a word meaning sour). 

 — Family, Geranium. Color, yellow. Leaves, on stem and 

 from roots, of 3 leaflets. Stipules, present. Time, all summer. 



Sepals, petals, styles, 5. Stamens, 10. Pods, long, erect, 

 weak-stemmed. 



The common yellow sorrel-flower varies greatly in size from 

 a buttercup to a small cinquefoil. - The plant is smooth or rough- 

 ish. 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 leaf- 

 lets at the approach of night. This species bears secondary blos- 

 soms, which are fertilized in the closed bud and are especially 

 fruitful. Strangely, the ordinary, more showy flowers absolute- 

 ly prevent self-fertilization by having stamens and anthers of 2 

 or even 3 different lengths, "dimorphous" or " trimorphous.'' 



18. Wild Strawberry 

 Fragaria Virginiana. — Family, Rose. Color, white. Leaves, 



