Helonias bullata

Distinct species in a monotypic genus.

Helonias bullata is known from the Coastal Plain of New Jersey, Delaware, Maryland, and Virginia (formerly also Staten Island, NY, where now extirpated), as well as from higher elevations in northern New Jersey, Virginia, North Carolina, South Carolina, and Georgia. Restricted to forested wetlands that are perennially water-saturated with a low frequency of inundation, habitat specificity appears to be a critical factor in this species' rarity. Approximately 225 occurrences are believed extant, over half of which are in New Jersey; 80 additional occurrences are considered historical and 15 are extirpated. The species is locally abundant at several sites in New Jersey, Delaware, Virginia, and North Carolina; some have 10,000+ clumps of plants. In addition to sites known to have been extirpated, significant habitat has been lost throughout the range due to factors such as drainage for agriculture. A number of local population declines have also been documented in the past 20 years. Degradation of this species' sensitive habitat via changes to the hydrologic regime is the primary threat. Such changes can be direct (ditching, damming, draining) or indirect (from development in the watershed); indirect impacts are particularly difficult to address. Other threats include poor water quality, invasive species, trash, all terrain vehicles, deer herbivory, trampling, and collection. Given this species' very specific hydrological requirements, climate change could also be an issue. H. bullata has limited ability to colonize new sites (low incidence of flowering, limited seed dispersal, poor seedling establishment) and low genetic variation, limiting its ability to adapt to changing conditions and recover when sites are destroyed.

Helonias bullata occurs on the Coastal Plain in southern New York state (Staten Island), New Jersey, Delaware, Maryland, and Virginia. Occurs at higher elevations (primarily disjunct bog areas in the Southern Appalachians) in northern New Jersey, Virginia, North Carolina, South Carolina, and Georgia. Extant populations in all states except New York. The greatest number of sites are in southern New Jersey, but the species is also locally abundant at some other sites, particularly in the Mid-Atlantic region.

Intensive survey efforts since this species was Federally listed have approximately doubled the number of known occurrences. Approximately 225 occurrences are believed extant, over half of which are in New Jersey; Virginia also has a considerable number (40+). Approximately 80 additional occurrences are considered historical, with the vast majority in New Jersey and a considerable number (14) in Delaware as well. 15 occurrences are extirpated, again mostly in New Jersey.

Habitat degradation is the primary rangewide threat. This degradation is difficult to address through either land protection or regulatory mechanisms because it is often brought about by off-site land uses, particularly development. Evidence of detrimental effects of development on H. bullata habitat and population quality continues to accumulate; such impacts are anticipated to worsen as development continues (USFWS 2007). A major component of habitat degradation is changes to the hydrologic regime. Such changes can be direct (e.g., ditching, damming, draining) or indirect (i.e, from development in the watershed). Indirect impacts often result from increased impervious surface in the watershed, which reduces infiltration and increases overland flow of stormwater, leading to increased stream erosion, wetland sedimentation, flood volumes and velocities, water level fluctuations, and hydrologic drought (USFWS 2007). Other components of degradation associated with adjacent development include poor water quality, invasive exotic species, trash, all terrain vehicles, herbivory by overabundant deer populations, trampling, and collection (USFWS 2007). Direct habitat losses have slowed, but historical losses were substantial (USFWS 2007). Because this species requires a very specific hydrology in order to thrive, climate change, which has the potential to either increase or decrease water levels at established sites, is an anticipated threat. For example, increased drought in southern Appalachians mountain bogs may already be having detrimental impacts. Also, about 10% of known occurrences are in areas with increased vulnerability to coastal flooding due to sea level rise (USFWS 2007).