The Bluets

Teacher’s Story

During April, great patches of blue appear in certain meadows, seeming almost like reflections from the sky; and yet when we look closely at the flowers which give this azure hue to the fields, we find that they are more lavender than blue. The corolla of the bluet is a tube, spreading out into four long, lavender, petal-like lobes; each lobe is paler toward its base and the opening of the tube has a ring of vivid yellow about it, the tube itself being yellow even to its very base, where the four delicate sepals clasp it fast to the ovary until the flower has done its work; and after the corolla has fallen the sepals remain; standing guard over the growing seed.

If we look carefully at the bluets we find two forms of flowers: (a) Those with a two-lobed stigma protruding from the opening of the flower tube. (b) Those where the throat of the tube seems closed by four anthers which join like four fingertips pressed together. In opening the flower, we observe that those which have the stigmas protruding from the tube, have four anthers fastened to the sides of the tube about halfway down; while those that have the four anthers near the opening of the tube, have a pistil with a short style which brings the stigmas about half-way up the tube. Thus an insect visiting flower (a) gets her tongue dusted with pollen from the anthers at the middle of the tube; and this pollen is applied at exactly the right place on her tongue to brush off against the stigmas of a flower of the (b) form. While a bee visiting a bluet of the (b) form receives the pollen at the base of her tongue, where it is conveniently placed to be brushed off by the protruding stigmas of the flowers of the (a) form.

This arrangement in flowers for the reciprocal exchange of pollen characterizes members of the primrose family also; it is certainly a very clever arrangement for securing cross-pollenation.