Northern Prairie Wildlife Research Center
Every county in North Dakota probably has a population of lambstongue ragwort. Elsewhere, the species occurs from southern Manitoba to British Columbia south to California and southern Colorado at elevations up to 10,000 feet.
Lambstongue ragwort is biennial or perennial from a short, button-like caudex (hardened stem base) with numerous fleshy-fibrous roots. Stems are single, crispy with long hairs when young, but hairless with age. North Dakota specimens usually are one to two feet tall. Most leaves are basal. These are up to six inches long and a half inch wide. Upper leaves become progressively smaller; the uppermost are only a half inch long. Leaves are mostly entire, but a few sometimes have small, irregularly-spaced teeth. Stems bear about 5-20 yellow flower heads, each about a half inch wide, that form a cyme (a flat-topped inflorescence with central flowers blooming first). Each head produces about 20 smooth seeds (achenes) with long white bristles to carry them away in the wind.
Look for lambstongue ragwort from mid to late May. Plants occupy low swales as well as dry slopes. Grazing seems to have little effect on the abundance of this plant in western North Dakota, where it seems to be most common. However, in the eastern part of the state, more plants are usually found in pastures that are moderately or heavily grazed.
Many Senecios, including several trees, in Africa, Eurasia, or North America, are used for medicines, foods, and ornamental woods, but S. integerrimus is not mentioned in these regards. The plant is listed as possibly causing liver dysfunction in cattle and horses, but does not seem to be a problem in North Dakota.
The ragworts are members of the sunflower family (Asteraceae). Aster means "star" in Greek, in reference to the radiate arrangement of the flowers in the heads. The family contains over 15,000 species, more than any other family in North Dakota as well as nearly every country in the North Temperate Zone. Senecio is an immense, worldwide genus of over 1,000 species, the name derived from the Latin senex, "an old man" likely in reference to the gray appearance of many species. The specific name integerrimus means "absolutely entire," in botanical Latin, probably in reference to the leaves, which are deeply toothed in most other ragworts.
Lambstongue ragwort was first described for science by the eminent English botanist-naturalist Thomas Nuttall (1786-1859) in his Genera Plantarum of 1818. He visited the Mandan villages along the Missouri River in 1810-1811.