About Narthecium americanum Ker Gawl.
Narthecium americanum Ker Gawl. is a species of flowering plant in the Nartheciaceae family, commonly called yellow asphodel and bog asphodel. It is native to New Jersey in the United States, and is now apparently limited to this state, having likely been extirpated from Delaware, North Carolina, and South Carolina.
This rhizomatous perennial herb grows an erect stem that is 25 to 45 centimeters tall. Narrow linear leaves up to 20 centimeters long and just a few millimeters wide grow around the base of the stem, with smaller leaves occurring higher up on the stem. The inflorescence is a dense raceme of yellow flowers that bloom in June and July. The fruit is a papery, beaked capsule that is one centimeter long or slightly longer, and contains yellow seeds.
This plant occurs in the Pine Barrens of New Jersey, where it grows along three tributaries of the Mullica River, including the Wading and Batsto Rivers. It grows in bogs, wet savannas, swamps, and other wet habitat types. While it may experience flooding, it does not persist in standing water. It is more abundant in canopy openings than in shaded areas.
Associated plant species in its habitat include Oclemena nemoralis, Calamagrostis pickeringii, Calamovilfa brevipilis, Juncus caesariensis, Lophiola americana, Muhlenbergia torreyana, Platanthera integra, Pogonia ophioglossoides, Rhynchospora oligantha, Schizaea pusilla, and Tofieldia racemosa. Sphagnum mosses are also common in this plant's habitat. This species is the "asphodel, that greeny flower" referenced by William Carlos Williams, a poet from East Rutherford, New Jersey.
Habitat degradation is currently the most significant threat to this species. Habitat was lost historically when it was converted for agricultural uses such as cranberry bogs, but direct habitat loss is no longer a major threat. Most of the species' populations are now protected within the Pine Barrens. Even so, habitat degradation still occurs through alteration of local hydrology and ecological succession. Any lowering of the water table in the Pine Barrens is likely to impact the local ecosystem, which relies on a water table near the surface. Fire suppression contributes to succession, which leads to overgrowth of large woody vegetation. This increases shade in the habitat, which negatively affects this species and many other herb layer species. Additional threats include off-road vehicles and picking or collecting of plants. Beaver dams can also cause flooding of habitat patches, which kills the plant.
