Northern Prairie Wildlife Research Center
A rather rare plant in North Dakota, leafystem fleabane has been collected several times west of the Missouri River, but only once east of the River. This is a western plant that ranges from Alberta and British Columbia south to Nebraska and New Mexico at elevations below 10,500 ft.
Leafystem fleabane is perennial from an underground woody structure called a caudex. Plants are up to two feet tall and covered with fine, spreading hairs. Basal leaves are up to five inches long and an inch wide. Unlike many Erigerons, this species has numerous leaves on the stem mostly as large as the basal leaves; only the uppermost leaves are noticeably reduced in size. Up to 20 flower heads about an inch wide form atop the stems and on the axils of upper leaves. Each head has 100-150 blue or rose-purple ray flowers. Fruits are achenes as in sunflower and dandelion.
Look for leafystem fleabane in August in meadows or around the bases of hills. I have no information on the effects of grazing on this species, but cattle seem to avoid eating the more common fleabanes. Some Erigerons are purported to drive away fleas, relieve toothache, and cure various diseases, but I could find no references to any economic values for leafystem fleabane.
This plant is a member of the sunflower family (Asteraceae), an immense group containing over 15,000 species worldwide. The family contains edible species such as lettuce and salsify, ornamentals like chrysanthemums and zinnias, and noxious weeds like thistles and cockleburs.
The generic name Erigeron stems from the Greek eri, "early" and geron "old man," in reference to early-flowering plants with a hoary appearance. The specific epithet subtrinervis probably refers to nerves on the achenes that usually number less than three. Leafystem fleabane was first named for science in 1894 by the Swedish-born American botanist Per Axel Rydberg (1860-1931), curator of the New York Botanical Garden and author of several major floras of the American west.