Distribution, Habitat Characteristics, and New County-level Records of Baccharis halimifolia L. on a Portion of its Present US Range Boundary

Baccharis halimifolia (Eastern Baccharis, Silverling, Groundsel-bush, or Salt-bush) (Asteraceae), a weedy shrub native to the US Gulf and Atlantic Coastal Plains, is believed to be expanding its distribution throughout much of its native range and in other regions of the globe to which it has been introduced (e.g.,Australia and Mediterranean Europe). The present survey represents an effort to document the current distribution of this species across a portion of its apparent interior range limit in the south-central United States and to record habitat associations of B. halimifolia within this region. Data support previous research suggesting that B. halimifolia associates with various forms of canopy-removing anthropogenic disturbance, and that the limit of this species' present distribution in the mid-South lies primarily along the southern half of counties in Tennessee. However, habitat associations did not appear to vary across the study area, suggesting potential for further expansion into human-altered habitats throughout Tennessee and possibly further northward.