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.
Flowers - Pinkish in bud, afterward purplish blue, fading to light blue; about 1 in. long, tubular, funnel form, the tube of corolla not crested; spreading or hanging on slender pedicels in showy, loose clusters at end of smooth stem from 1 to 2 ft. high; stamens 5, inserted on corolla; 1 pistil; ovary of 4 divisions. Leaves: Large, entire, alternate, veiny, oblong or obovate, the upper ones seated on stem; lower very large ones diminishing toward base into long petioles; at first rich, dark purple, afterward pale bluish gray. Fruit: 4 seed-like little nuts, leathery, wrinkled when mature.
Flowering Season - March - May.
Distribution - Southern Canada to South Carolina and Kansas, west to Nebraska; most abundant in middle West.
Not to be outdone by its cousins the heliotrope and the forget-me-not, this lovely and far more showy spring flower has found its way into the rockwork and sheltered, moist nooks of many gardens, especially in England, where Mr. W. Robinson, who has appealed for its wider cultivation in that perennially charming book, "The English Flower Garden," says of the Mertensias: "There is something about them more beautiful in form of foliage and stem, and in the graceful way in which they rise to panicles of blue, than in almost any other family. . . .
Handsomest of all is the Virginia cowslip." And yet Robinson never saw the alluvial meadows in the Ohio Valley blued with lovely masses of the plant in April.
A great variety of insects visit this blossom, which, being tubular, conducts them straight to the ample feast; but not until they have deposited some pollen brought from another flower on the stigma in their way. The anthers are too widely separated from the stigma to make self-fertilization likely. Occasionally one finds the cowslips perforated by clever bumblebees. As only the females, which are able to sip far deeper cups, are flying when they bloom, they must be either too mischievous or too lazy to drain them in the legitimate manner. Butterflies have only to stand on a flower, not to enter it, in order to sip nectar from the four glands that secrete it abundantly.