Rorippa palustris var. palustris  (R. islandica) common yellow-cress Brassicaceae ROPA2*; Bx, pb; Q, a, f; K; R, e, v;

 

Rorippa palustris var. palustris.Barry Breckling.calphotos.berkeley.edu

Rorippa palustris var. palustris.Barry Breckling.calphotos.berkeley.edu

Rorippa palustris var. palustris is an annual or biennial herb, taprooted, erect, to 40 cm tall, branched. 

Leaves alternate, narrow, pinnately divided, stem leaves winged near base, with small, ear-shaped lobes. 

Flowers yellow, 4-parted, about 0.3 cm wide, petals about as long as sepals; blooming May-Aug. 

Fruit a capsule oblong-cylindrical ca 0.5 cm long, with a small blunt beak, seeds in two rows on each side; fruiting July-Oct. 

Wetland status: OBL. 

Frequency in NYC: infrequent. 

Origin: Eurasia. 

Habitat: Moist to wet open areas. Sometimes a lawn weed in moist soil.