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Aquatic and Wetland Vascular Plants of the Northern Great Plains

Brassicaceae - The Mustard Family

Annual, biennial or perennial herbs with alternate, exstipulate, simple to compound leaves, the blades entire to dentate, sinuate, laciniate or pinnately lobed or divided. Flowers in terminal and lateral, ebracteate racemes, these indeterminate in development so that the lower portion is often in fruit while flowers continue to be produced at the tip; pedicels elongating in fruit. Flowers minute to conspicuous, perfect, regular; sepals 4, usually deciduous; petals 4, yellow, white or pink, clawed at the base; stamens 6, the outer 2 stamens shorter than the inner 4; pistil 1, 2-carpellary, style 1, short, elongating in fruit, ovary superior, 2-celled, elongating or enlarging in fruit, maturing into an elongate to cylindrical or globose, sometimes curved, 2 (rarely 4)-valved capsule (termed a silique in those included here), the 2 halves separated by a membranous replum which persists on the pedicel after dehiscence, the seeds in 1 or 2 rows in each cell of the fruit.

Lead Characteristic Go To
1 Flowers white or pink. Lead 2
1 Flowers yellow or yellowish-green. Lead 4
2 Plants stoutly taprooted; siliques distinctly stipitate, borne on a stipe that extends about 1 mm or more beyond the tip of the pedicel. Genus Thelypodium
2 Plants fibrous-rooted, sometimes bulbous at the base as well; siliques sessile on the pedicels. Lead 3
3 Seeds in 1 row in each cell of the silique; plants of wet habitats but not usually growing in water. Genus Cardamine
3 Seeds in 2 rows in each cell of the silique; plants usually growing in water. Genus Nasturtium
4 Siliques linear or curved-linear, 20-30X or more longer than wide; seeds in 1 row in each cell of the silique. Genus Barbarea
4 Siliques linear-elongate or cylindrical to globose, 1-8(10)X longer than wide; seeds in 2 rows in each cell of the silique. Genus Rorippa

22. Brassicaceae, the Mustard Family
1. Barbarea R. Br. -- Winter cress
1. Barbarea vulgaris R. Br.
2. Cardamine L. -- Bitter cress
1. Cardamine bulbosa (Schreb.) B.S.P. -- Spring cress
2. Cardamine pensylvanica Muhl. ex Willd. -- Bitter Cress
3. Nasturtium R. Br. -- Watercress
1. Nasturtium officinale R. Br.
4. Rorippa Scop. -- Yellow cress
1. Rorippa austriaca (Crantz) Bess. -- Austrian field cress
2. Rorippa calycina (Engelm.) Rydb.
3. Rorippa curvipes Greene
4. Rorippa palustris (L.) Bess. -- Bog yellow cress
5. Rorippa sinuata (Nutt.) A.S. Hitche -- Spreading yellow cress
6. Rorippa sylvestris (L.) Bess. -- Creeping yellow cress
7. Rorippa tenerrima Greene
8. Rorippa truncata (Jeps.) Stuckey
5. Thelypodium Endl.
1. Thelypodium integrifolium (Nutt.) Endl.

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