Description ⁶

This biennial or annual plant is 1-3' tall; it is normally erect and branches occasionally to frequently. The stems are light green to reddish green, glabrous, and strongly furrowed or ribbed. The alternate leaves are up to 7" long, 2" across, becoming smaller as they ascend the rather zigzag stems. The variable leaves are oblanceolate or oblong-ovate, hairless, pinnately lobed (usually), and dentate or crenate along the margins. Often, there are 1-2 pairs of moderately deep lobes near the base of each leaf, and shallow lobes or large teeth elsewhere. The lower leaves have stout petioles, while the upper leaves are usually sessile, or nearly so. The leaf tips are variable in shape, ranging from blunt to acute. The upper stems terminate in racemes of flowers about 2-8" long; more than one raceme may develop from a single stem. The small flowers bloom at the apex of each raceme, while the siliques (cylindrical seedpods) develop below. Each flower is about 3 mm. (1/8") across, consisting of 4 yellow petals, 4 greenish yellow sepals, several stamens with yellow or light brown anthers, and a pistil with a stout style. The blooming period usually occurs during the summer and lasts about 2 months. The siliques are 6-8 mm. (0.24-0.32") long, hairless, and slightly knobby; their shape is short and cylindrical (rather like little sausages, except they're green). They have neither stipes nor beaks. The slender pedicels are light green, terete, and up to ½" long. Relative to the central axis of the raceme, the siliques and their pedicels are ascending to widely spreading. Within each silique, there are two rows of small seeds. The root system consists of a taproot that is shallow and branching. This plant spreads by reseeding itself. Cultivation

Sources and Credits

1. (c) Barry Breckling, some rights reserved (CC BY-NC-SA), https://calphotos.berkeley.edu/imgs/512x768/0000_0000/0311/1326.jpeg
2. (c) Barry Breckling, some rights reserved (CC BY-NC-SA), https://calphotos.berkeley.edu/imgs/512x768/0000_0000/0311/1327.jpeg
3. USDA NRCS PLANTS Database, no known copyright restrictions (public domain), https://plants.usda.gov/gallery/large/rapa7_001_lvd.jpg
4. (c) John Hilty, some rights reserved (CC BY-NC), http://www.illinoiswildflowers.info/wetland/photos/marsh_ylcress1.jpg
5. (c) John Hilty, some rights reserved (CC BY-NC), http://www.illinoiswildflowers.info/wetland/photos/marsh_ylcress2.jpg
6. (c) John Hilty, some rights reserved (CC BY-NC), http://eol.org/data_objects/29444594

More Info

• iNat taxon page
• Biodiversity Heritage Library
• BOLD Systems BIN search
• eFloras.org
• Flora of North America (beta)
• Global Biodiversity Information Facility (GBIF)
• HOSTS - a Database of the World's Lepidopteran Hostplants
• IPNI (with links to POWO, WFO, and BHL)
• NatureServe Explorer 2.0
• SEINet Symbiota portals
• Tropicos
• USDA PLANTS database
• VASCAN by Canadensys
• World Flora Online

Range Map

(c) Discover Life and original sources, some rights reserved (CC-BY-NC-SA)

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