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Aquatic and Wetland Vascular Plants of the Northern Great Plains

22. Brassicaceae, the Mustard Family

4. Rorippa Scop. -- Yellow cress

1. Rorippa austriaca (Crantz) Bess. -- Austrian field cress

Stout, erect perennial 3-9 dm tall, from a fleshy taproot, often forming patches by creeping rootstocks, simple or branched from the base, branched toward the tip, glabrous to minutely strigose or puberulent on the leaves and stems. Leaves short-petioled near the base, becoming smaller, sessile and auriculate-clasping upward, the blades elliptic to oblanceolate, 3-10 cm long, 0.8-4 cm wide, obtuse to rounded at the tip, irregularly serrate to subentire, unlobed except for the auriculate-clasping base. Racemes terminal and in upper axils, often branched. Sepals yellowish-green, 1.5-2 mm long; petals yellow, 2-3 mm long, exceeding the sepals. Siliques rarely producing seed, globose, 1-2 mm long, the persistent style about equaling or exceeding the fruit body; pedicels spreading or a few recurved, 6-10(15) mm long. Jun--Aug. Low wet areas in and near fields; uncommon, intro. at scattered points in e and c ND, e SD and e NE, showing little proclivity for spreading; (Intro. from Europe and found at scattered localities in the U.S. and Can.).
GIF- Distribution Map

Map key

Previous Species -- Nasturtium officinale R. Br.
Return to Family -- Brassicaceae - The Mustard Family
Next Species -- Rorippa calycina (Engelm.) Rydb.

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