Family: Brassicaceae
watercress
[Nasturtium nasturtium-aquaticum (L.) H.Karst., more...]
Christopher Noll
University of Wisconsin-Milwaukee (UWM)
Etymology: Nasturtium: Latin nasus for “nose” and tortum for “to twist”, referring to the pungent taste
Plants: erect or spreading, perennial, 4"-18" tall, emergent aquatic, sometimes evergreen, forming large, tangled masses; stems spreading; rooting from the lower nodes
Leaves: pinnately-divided into 3-9 rounded leaflets with the end one longest
Flowers: white, 4-parted, 1/5" wide, petals 2 times longer than the sepals; inflorescence a cluster (raceme) of stalked flowers from the ends of the shoots
Fruits: pod, long, thin; coarse seeds in 1 rows
Habitat: sun; wet; streams, springs, cold water; in limy, sediment, gravelly soil
Plants: erect or spreading, perennial, 4"-18" tall, emergent aquatic, sometimes evergreen, forming large, tangled masses; stems spreading; rooting from the lower nodes
Leaves: pinnately-divided into 3-9 rounded leaflets with the end one longest
Flowers: white, 4-parted, 1/5" wide, petals 2 times longer than the sepals; inflorescence a cluster (raceme) of stalked flowers from the ends of the shoots
Fruits: pod, long, thin; coarse seeds in 1 rows
Habitat: sun; wet; streams, springs, cold water; in limy, sediment, gravelly soil
Coldwater streams, rivers, ditches, lowland forests, rocky waterfalls, conifer swamps, sedge meadows, marshes, alder thickets, springs, fens. This is a highly invasive species, forming dense floating or creeping mats in the waterways and wetlands where it grows. Considered by some to be native to North America but it seems more likely that American plants are all European introductions. First collected in Wisconsin in 1860.
Floristic Rating: Wetland Indicator = OBL USDA Plants Database: Federal Distribution and detailed information including photos
Merel R. Black
Matthew L. Wagner
Robert W. Freckmann
Christopher Noll
Merel R. Black
Steve C. Garske
Merel R. Black
Richard Bauer
Paul Skawinski
Derek Anderson
Kurt Stüber
Marion Sheehan
