Borodinia serotina

FNA (2010, vol. 7) accepts the treatment of this species in Boechera, as Boechera serotina. Alexander et al. (2013) distinguish it in a separate genus, as Borodinia serotina.

Boechera serotina is a narrow endemic of the eastern United States, known only from the shale barrens region of Virginia and West Virginia. It is one of the most restricted shale barren endemics. There are approximately 62 occurrences believed extant, most of these made up of fewer than 50 individuals; there are perhaps fewer than 4,000 plants altogether. Most occurrences are on public lands, predominantly National Forests. Due to the highly edaphic nature of shale barren environments, this species is not believed to be capable of tolerating many additional stressors. Threats include road/trail construction and maintenance, erosion, inundation resulting from flood control measures, deer browsing, competition from exotic plants, and declines of its pollinators due to the spraying of Dimilin and BT insecticides for the introduced Spongy Moth (Lymantria dispar) control.

This species occurs in the eastern United States, where it is a narrow endemic of the shale barren regions of Virginia and West Virginia. It is one of the most restricted shale barren endemics. Occurrences have been documented in six Virginia counties (Alleghany, Augusta, Bath, Highland, Page, Rockbridge) and three West Virginia counties (Greenbrier, Hardy, Pendelton) (USDA Forest Service 2000, Ludwig 1995, USFWS 1989, Bartgis 1987, Bartgis and Wieboldt 1986, Artz 1948).

There are approximately 62 occurrences believed to be extant with 35 in Virginia and 27 in West Virginia.

Numerous threats are currently impacting B. serotina. The construction of roads, railroads, and hiking trails has impacted occurrences in the past; several occurrences are now located adjacent to these corridors where they may be impacted by erosion or maintenance activities. Flood control measures are a potential threat at some locations (e.g. South Fork Valley of West Virginia) (Bartgis in litt.); one barren has already been destroyed by a stream dam (Dix 1990). Most extant occurrences are moderately to severely browsed by deer, which is considered by some to be a prime threat to the species (USFWS 1989; USFWS 2010); quantifying the impact of deer browsing is an area of active research (Ludwig pers. comm.). Moderately xeric sites may be subject to encroachment of exotic plant species such as Ailanthus altissima, Centauria maculata and numerous grasses (Dix 1990). Such encroachment is a particular concern for Boechera serotina since it does not tolerate competition well; it is generally restricted to the more open portions shale barren communities. A significant threat to the insect pollinators of B. serotina is presented by the spraying of Dimilin and BT insecticides for the introduced Spongy Moth (Lymantria dispar) control. Because of the open habitat, shale barren insects are maximally exposed to pesticides (Dix 1990). Dimilin is a broad-spectrum biocide that persists until leaf fall and up to a few years in the duff and would have a long-term impact of shale-barren slopes. All insect occurrences on shale-barrens sprayed with Dimilin should be considered extirpated (Schweitzer in litt). BT is lepidopteran-specific and only persists for roughly one week (Dix 1990). Application during larval development may have devastating impacts on the fauna, however. Finally, the very small number of individuals within many occurrences suggests that the long-term persistence of these occurrences is uncertain, especially considering that populations tend to fluctuate dramatically.