White and Greenish 



ground in rich woods, often beside a spring, from April to June — 

 a longer season for wooing and working its insect friends than 

 the two-leaved toothwort has attained to — hence it is the com- 

 moner plant. Instead of having two leaves on its stem, this 

 species spreads whorls of three leaves, thrice divided, almost to 

 the base, the divisions toothed or lobed, and the side ones some- 

 times deeply cleft. The larger, longer petioled leaves that rise- 

 directly from the rootstock have scarcely developed at flowering 

 time. 



Shepherd's Purse; Mother's Heart 



(Bursa Bursa-pastoris) Mustard family 



(Capsel/a Bursa-pastoris of Gray) 



Flowers — Small, white, in a long loose raceme, followed by triangu- 

 lar and notched (somewhat heart-shaped) pods, the valves 

 boat-shaped and keeled. Sepals and petals 4 ; stamens 6 ; 

 1 pistil. Stem: 6 to 18 in. high, from a deep root. Leaves: 

 Forming a rosette at base, 2 to 5 in. long, more or less cut 

 (pinnatifid), a few pointed, arrow-shaped leaves also scattered 

 along stem and partly clasping it. 



Preferred Habitat — Fields, roadsides, waste places. 



Flowering Season — Almost throughout the year. 



Distribution — Over nearly all parts of the earth. 



From Europe this little low plant found its way, to become 

 the commonest of our weeds, so completing its march around the 

 globe. At a glance one knows it to be related to the alyssum and 

 candy-tuft of our gardens, albeit a poor relation in spite of its 

 vaunted purses — the tiny, heart-shaped, seed-pods that so rapidly 

 succeed the flowers. What is the secret of its successful march 

 over the face of the earth ? Like the equally triumphant chick- 

 weed, it is easily satisfied with unoccupied waste land, it avoids 

 the fiercest competition for insect trade by prolonging its season 

 of bloom far beyond that of any native flower, for there is not a 

 month in the year when one may not find it even in New England 

 in sheltered places. Having vanquished in the fiercer struggle for 

 survival in the Old World, it finds life here one long holiday ; and 

 finally, by clustering a large number of relatively small flowers 

 together, it attracts the insects that this method of arrangement 

 pleases best, the flies (Syrphidae and Muscidae) which cross-fertil- 

 ize it in fine weather, transferring enough pollen from plant to plant 

 to save the species from degeneracy through close inbreeding. 

 However, the long stamens standing on a level with the stigma 

 are well calculated to self-pollenize the flowers, the flies failing 

 them. 



191 



