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 - Purplish rose, about 1/2 in. across, borne chiefly in pairs on slender peduncles. Five sepals and petals; stamens 10; pistil with 5 styles. Stem: Weak, slender, much branched, forked, and spreading, slightly hairy, 6 to 18 in. high. Leaves: Strongly scented, opposite, thin, of 3 divisions, much subdivided and cleft. Fruit: Capsular, elastic, the beak 1 in. long, awn-pointed.
Per/erred Habitat - Rocky, moist woods and shady roadsides.
Floweri?ig Season - May - October.
Distribution - Nova Scotia to Pennsylvania, and westward to Missouri.
Who was the Robert for whom this his "holy herb" was named? Many suppose that he was St. Robert, a Benedictine monk, to whom the twenty-ninth of April - the day the plant comes into flower in Europe - is dedicated. Others assert that Robert Duke of Normandy, for whom the "Ortus Sanitatis," a standard medical guide for some hundred of years, was written, is the man honored; and since there is now no way of deciding the mooted question, we may take our choice.
Only when the stems are young are they green; later the plant well earns the name of red shanks, and when its leaves show crimson stains, of dragon's blood.
At any time the herb gives forth a disagreeable odor, but especially when its leaves and stem have been crushed until they emit a resinous secretion once an alleged cure for the plague. Flies, that never object to a noxious smell, constantly visit the flower, and have their tongues guided through passages between little ridge-like processes on each petal to the nectar secreted by the base of the filaments at the base of each sepal. To prevent self-fertilization, the five stigmas are folded close together when the flower opens, nor do they spread apart and become receptive until after the outer row of anthers, then the inner row, have shed their pollen. When the elastic carpels have ripened their seed, bang! go the little guns, scattering them far and wide.