276 BRASSICACEAE 



short ; stigma 2-lobed or capitate. Seeds in 1 row in each cell, flat, oblong, marginless ; 

 cotyledons accumbent. [Name in honor of Saint Barbara.] 



A genus of about 7 species, natives of the temperate zones. Type species, Barbarea vulgaris R. Br. 



1. Barbarea americana Rydb. American Winter Cress. Fig. 2021. 



Barbarea americana Rydb. Mem. N.Y. Bot. Gard. i: 174. 1900. 

 Barbarea orthoceras var. dolichocarpa Fernald, Rhodora 11: 140. 1909. 



Biennial, glabrous throughout, often purple-tinged, the stems rather stout, erect, 3-6 dm. 

 high Basal leaves lyrately pinnatifid, with a large terminal leaflet and 2-4 pairs of small lateral 

 ones' the stem leaves lyrately pinnatifid or lobed, becoming reduced above; petals pale yellow; 

 pods' ascending, 3-4.5 cm. long, 1.5 mm. broad, obscurely 4-angled; beak rather stout, 1-1.5 



mm. long. 



Moist places, Transition and Upper Sonoran Zones; British Columbia to Montana south to northern 

 Mexico and Lower California. This is a native species long confused with B. vulgaris I. wh.ch is widely 

 introduced in the eastern United States. Type locality. Spanish Basin, Montana. March-Oct. 



Barbarea stricta Andrz. in Bess. Enum. PI. Volh. 72. 1822 Differs from the native species chiefly in 

 the stouter pods which are erect and appressed to the rachis. Widely introduced in the United States but rare 

 on the Pacific Coast. This has been referred by some authors to B. orthoceras Ledeb. Native of Europe. 



Barbarea verna (Mill.) Aschers. Fl. Brand. 1 : 36. 1864. Divisions of the leaves more numerous, usu- 

 ally 4-8 pairs of rather narrow lateral leaflets; pods sharply 4-sided and, slightly compressed, spreading or 

 ascending. In waste places, sparingly introduced in the Pacific States. Native of Europe. 



26. RORIPPA Scop. Fl. Cam. 520. 1760. 



Aquatic or marsh herbs, with simple or pinnate, lobed, dissected or rarely entire leaves 

 and small white or yellow, racemose flowers. Sepals spreading. Stamens often less than 

 6 Style short or slender ; stigma 2-lobed or nearly entire. Pods short, terete or nearly so, 

 not stipitate; valves nerveless or 1 -nerved. Seeds minute, turgid, in 2 rows in each cell; 

 cotyledons accumbent. [Name unexplained.] 



About 50 species, of wide distribution, but mainly in the north temperate zone. Type species, Sisym- 

 brium amphibium L. The older generic name Radicula Hill (1756) is not available according to the Inter- 

 national Rules, Art. 67. The original spelling, Rorippa, was changed by Adanson to Roripa, and many authors 

 have used that spelling but according to the International Rules the original spelling should be retained. 



Flowers white. 



Leaves pinnately divided; pods linear. 1- R- Nasturtium-aquaticum. 



Leaves at least the upper simple; pods ovoid. 8. R. Armoracia. 



Flowers yellow; leaves pinnatifid or pinnate. 



Plants perennial by creeping rootstocks; petals well exceeding the sepals. 



Pods glabrous or nearly so. 2 - R - sinuata. 



Pods short-pubescent. 3 - R - columbiae. 



Plants annual, biennial, or perennial, with fibrous roots, and without creeping rootstocks; petals scarcely 

 equaling the sepals. 

 Stems diffusely branching from the base; pedicels 2-4 mm. long. 



Pods strongly curved; leaf -segments linear to oblong, mostly acute; style not over 0.5 mm. long, 

 stout. 4. R. curvtstltqua. 



Pods not curved; leaf -segments obovate or rounded; style 1-2 mm. long, slender. 



5. R. obtusa. 



Stems erect, branched above; pedicels 6-8 mm. long. 



Stems nearly or quite glabrous; pods linear or linear-oblong. 6. R. palustris. 



Stems hispid-pubescent; pods globose or ovoid. 7. R. hispida. 



1. Rorippa Nasturtium-aquaticum (L.) Schinz & Thell. Water-cress. 



Fig. 2022. 



Sisymbrium Nasturtium-aquaticum L. Sp. PI. 657. 1753. 



Nasturtium officinale R. Br. in Ait. Hort. Kew. ed. 2. 4: 110. 1812. 



Radicula Nasturtium-aquaticum Britten & Rendle, List Brit. Seed-Plants 3. 1907. 



Rorippa Nasturtium-aquaticum Schinz & Thell. Fl. Schweiz ed. 3. 240. 1909. 



Stems floating, creeping or ascending, rooting at the nodes, glabrous. Leaves pinnately 

 divided into ovate or oval segments, the terminal larger; racemes elongated in fruit ; petals 

 white, 3-4 mm. long ; pedicels 1-2 cm. long ; pods 1-3 cm. long, 2 mm. wide, spreading or slightly 

 curved upwards. 



Margins of streams, or quiet water; naturalized and common in the Pacific States. Native of Eurasia. 

 March-Nov. 



2. Rorippa sinuata (Nutt.) A. S. Hitchcock. Spreading Yellow-cress. 



Fig. 2023. 



Nasturtium sinuatum Nutt. in Torr. & Gray, Fl. N. Amer. 1 : 73. 1838. 

 Rorippa sinuata A. S. Hitchcock, Spring Fl. Manhattan 18. 1S94. 

 Radicula sinuata Greene, Leaflets Bot. Obs. 1: 113. 1905. 



Perennial from creeping rootstocks, diffuse, glabrous, the branches ascending. Leaves5-8 

 cm. long, pinnatifid, the segments linear to oblong, obtuse, entire or sparingly dentate ; pedicels 



