General in middle states.
Flowers; whorled in a terminal, wand-like spike, tipped a little at the end. Calyx: circular, with five to seven toothed points. Corolla: of five, six or seven long, narrow, petals; slightly puckered. Stamens: twelve, in two sets of different lengths. Pistil: one; varying in length in the different blossoms. Leaves: opposite; lanceolate; sessile; the lower ones heart-shaped at base. Stem: tall; smooth.
Professor Darwin wrote to Doctor Gray about these flowers: "I am almost stark, staring mad over lythrum. If I can prove what I really believe it is a grand case of trimorphism, with three different pollens and three stigmas. I have fertilized above ninety flowers, trying all the eighteen distinct crosses which are possible within the limits of this one species. For the love of Heaven, have a look at some of your species and if you can get me some seed, do."
Calyx and Fruit.
Professor Darwin did prove successfully what he believed. In each flower the two sets of stamens and the pistil are of different lengths; and in order to effect fertilization, the stigma must receive the pollen from stamens that are the same length as itself. As in dimorphous flowers, this is one of the most ingenious devices to guard against self-fertilization.
The plant is not related, as its common name would imply, to the other loosestrifes, which are members of the primrose family. It is a European, very lovely in appearance, which has taken kindly to our wet soggy soil.