A Shrub of the Ericaceæ

  • Taking first the families that all have a superior ovary, we must, for lack of space, exclude most of them from here. A few of the most important, or typical, after the Ericaceæ, are:

    • Primulaceæ—Primrose family. All herbs in which the stamens are as many as the lobes of the corolla and inserted on them. The flowers are quite regular. They all have some form of a capsule for fruit, which in most generally split lengthwise. Familiar examples include the garden primrose (not the wild evening primrose), yellow loosestrife, the star flower, pimpernel, shooting star, and the beautiful cyclamens. A few members of the family are slightly luminous in the dark, apparently an attraction to night-flying insects. About 28 genera and over 400 species, mostly from the northern hemisphere, a few in temperate South America and South Africa.
    • Gentianaceæ—Gentian family. Over 700 species in 70 genera, all bitter herbs, with opposite leaves, quite without teeth and beautiful, sometimes fringed, always regular flowers. In this and related families the stamens are of the same number as the lobes of the corolla, and always alternate with them. Gentian and sea or marsh pinks are our best-known native representatives, while some related plants are medicinal.

    There are many other families in this part of the scheme of plant classification that have minor differences among themselves, but agree pretty generally in the number and position of their stamens, their superior ovary, and, on the whole, in the regular flower. Irregular and regular flowers may be recognized at once by cutting them lengthwise through the middle. In regular flowers there would be as much on one side as on the other of the dividing line, and in irregular ones quite obviously more on one side than the other. The character of all the genera in a family having irregular flowers begins to occur here with greater and sometimes exclusive frequency. In the mint family, or Lamiaceæ, nearly all of its 160 genera and over 3,000 species have two-lipped or irregular flowers. The garden salvia well illustrates the type.

  • In some plants this is accomplished by the anthers being just above the stigma, and when the pollen is ripe and the ovule ready, the stigma is found to be covered with a sticky substance. As the falling pollen grains touch the stigma, they are caught in this sticky substance just as surely as flies are caught once they touch a fly paper. But just here one of the most wonderful processes of nature begins. The pollen grain begins, slowly at first, to grow, and in the act it penetrates the outer coat of the stigma with a minute pollen tube.

    This slender threadlike tube, carrying with it the male germ, grows straight down through the stigma, into the narrowed style, and through this to the ovule. Once the pollen is caught on the stigma, nothing is so sure of fulfillment as that this male fertilizing stuff will ultimately reach the ovule. For the hitherto virgin ovule this impregnation starts a new phase in life. It means the beginning of the end, but in the process fruit and seed will be developed, and the young bride, already a mother, has triumphantly accomplished that for which she exists.