NPSpecies

Data Source: Killip, 1931;Maxon, 1935;Wiegand, 2001; Wiegand, 2001b;

Data Source: Helen Hamilton

Data Source: Helen Hamilton

Park Species Detail: Killip, 1931: Frequent in shallow pools and at their margins. Sept. 8. A striking plant with bright yellow flowers, in shallow pools and on muddy flats as the water receded. Previously reported from the channel by Maxon and McAtee. Maxon, 1935: Rare. Wiegand, 2001b: An uncommon watchlist plant species occurring in low, wet areas, scour and deposition bars along the river, flood channels, low pools and other permanently wet or frequently flooded habitats. Scattered on mud flats, around pools and semi-aquatic habitats on the shoreline of the river along the length of this survey site. It was quite abundant during the low river levels of 1999, but almost disappeared during 2000 when river levels remained unusually high during much of the growing season. Further up river, water-stargrass was seen in great masses covering acres of the river during the drought that lasted from 1997 through 1999. An uncommon plant species occurring in low, wet areas, scour and deposition bars along the river, flood channels, low pools and other permanently wet or frequently flooded habitats. Water-stargrass (Heteranthera dubia) is scattered on mud flats, around pools, in wet swales and other aquatic and semi-aquatic habitats near the shoreline of the river below Fletcher's Boathouse. It can be quite abundant some years and nearly absent from the area other years. Further up river, water-stargrass was seen in great masses during the drought from 1997 through 1999. Found at 3 locations. A watch list (and otherwise uncommon) plant species known to occur within the District of Columbia portion of LOCO (along the C&O Canal NHP and Potomac River from the Maryland line to Key Bridge, Washington, D.C.)Hamilton, 2007: See Zosterella dubia, a synonym., Park Species Data Source: Killip,1931;Maxon, 1935;Wiegand, 2001;Wiegand, 2001b;