This section is from the book "Nature's Garden", by Neltje Blanchan. Also available from Amazon: Nature's Garden; An Aid To Knowledge Of Our Wild Flowers And Their Insect Visitors.
Flotvers - Small, white, in a long loose raceme, followed by triangular 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-fertilize 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.