MARSH SANDWORT

image: turtlepuddle.org

Marsh sandwort is a delicate herbaceous perennial, producing mat-like clusters of erect, slender shoots from underground runners (Abrams and Ferris 1944; Hartman et al. 2005; Hitchcock 1964; Mason 1957). The vegetative shoots often twine around each other or sprawl over associated vegetation and have been reported to reach up to 1 meter in length. Shoots typically have many pairs of opposite, linear leaves, with blades 1-2 cm long. The flowering shoots, which produce small, solitary, white flowers, often ascend among the leaves and stems of other marsh plants like rushes and sedges. Flowers are about 8-10 mm wide at anthesis, bear 5 white petals, and 10 stamens. Flowering is sporadic, ranging from May through August. Each flower produces a few, small, black seeds, but the type of potential pollinator remains unknown (Mazer and Waddell 1994; Mazer 2000).Marsh sandwort today is known from fewer than three localities, and its numbers have dwindled to perhaps less than perhaps 50 individuals. marsh sandwort is known from as few as two localities in southern San Luis Obispo County. At one of these localities, it co-occurs with Gambel’s watercress, another endangered species. Marsh sandwort has been reported from Mexico and Guatemala, but its distribution there also appears to be highly restricted.

 Threats

•Loss of wetlands and sporadic inundation of stable wetland habitats. •Competition from alien invasives. •Eutrophication resulting from increased nutrient levels.

Source: Center for Plant Conservation