This section is from the book "The Gardener's Monthly And Horticulturist V20", by Thomas Meehan. See also: Four-Season Harvest: Organic Vegetables from Your Home Garden All Year Long.
This handsome flower, which is quite common in the vicinity of Washington, and which blooms about the end of July, presents a device for the prevention of self-fertilization, which has not, it is believed, been met with in any other species of plant, and so far as I am aware, has not yet been described.
The flower has five stamens with elongated, introrse anthers, which are abruptly curved outward near the summit, and a single style about the length of the stamens terminated by a forked stigmatic portion nearly as much longer. These branches of the style which are stigmatic on the inside are at first closely twisted together in such a manner as to conceal the stigmatic surfaces. Later they untwist and present a simply bifurcate appearance, but this does not take place until the anthers have shed most of their pollen, by which the advantages of dichogamy are in a measure secured, the pollen of the later flowers being conveyed by insects to the stigmas of earlier ones. But in addition to this, the style is in all cases found to be abruptly bent at the base, so as to form an angle of from forty-five to ninety degrees with the perpendicular, carrying the stigmas entirely away from the stamens, and usually locating them between the lobes of the corolla. And as if this were not enough, the stamens also are found in a great majority of cases to be bent in the opposite direction , so as to lean more or less conspicuously away from the center, while in many of the flowers the filaments lie flat down upon the floral envelopes, the style at the same time occupying a horizontal position on the other side.
At a later stage, and after fertilization has been effected, both the stamens and the style partially or completely regain the erect position.