Culture
Best in organically rich, consistently moist but well-drained soils in full sun to part shade. Soils should not be allowed to dry out.
Noteworthy Characteristics
Marshallia mohrii, commonly known as Mohr’s barbara buttons, is a perennial herb of the aster family that grows on branching stems to 28” tall. Since 1987, it has been listed as a Threatened Species under the Federal Endangered Species Act of 1973, as amended. It is currently found only in the southern Appalachians in north central Alabama and northwestern Georgia. It is native to seasonally wet, sandy-clay soils in prairie-like meadows, along margins of shale-bedded streams, public utility/highway rights-of-way, and in habitats with widely spaced trees (barrens or glades). Most currently known populations occur on private land.
Erect stems often branching near the top to 28” tall are clad with lance-shaped leaves (to 3-8” long and 3/4” wide), each leaf having three conspicuous parallel veins. Leaf size decreases toward the top of the plant. Five-lobed, enlarged and twisted, pale pink or white disk flowers (rays flowers absent) bloom in flower heads (each to 1” across) located singly on tall stems rising above the foliage from mid-May to the end of June. Each flower head is subtended by a whorl of pointed persistent bracts. Fruits are 5-angled achenes which are somewhat hidden among the flower head bracts.
Plants have suffered habitat loss over the years for a number of reasons including (a) fire suppression (M. mohrii habitat such as open glades becomes overgrown with vegetation and woody species when natural fires are suppressed to protect oaks, pines and human development), (b) vegetation management practices along roads (mowing and herbicide applications), (c) road construction, and (d) conversion of land to agricultural and/or residential development.
Genus name honors Humphry Marshall (1722-1801) and his nephew Moses Marshall (1758-1813), American botanists.
Specific epithet honors Charles Mohr (1824-1901), pharmacologist and plant collector who authored Plant Life of Alabama and who made the first dated discovery of this species in Cullman County, Alabama in 1882.
Problems
No serious insect or disease problems.
Uses
Threatened species that may be difficult to locate in commerce. Rock gardens. Border fronts. Native plant gardens. Watersides.