124 CRUCIFERAE. (Vou. II. 
1. Roripa sylvéstris (L.) Bess. 
Creeping Yellow Water-cress. 
(Fig. 1713.) 
Sisymbrium sylvestre 1. Sp. Pl. 657. 1753- 
Nasturtium sylvestre R. Br. in Ait. Hort. Kew. Ed. 
2,4:110. 1812. 
Roripa sylvestris Bess. Enum, 27. 1821. 
Perennial, glabrous; stems creeping, branches 
ascending. Leaves pinnately divided or deeply 
pinnatifid, petioled, 3’-5’ long, 1/-2’ broad, 
ovate in outline, the divisions obovate, or ob- 
long, toothed or lobed, the terminal one often 
somewhat larger than the lateral; pedicels slen- 
der, 3’ long; flowers yellow, 3/’-4’’ broad; pod 
linear, 4’’-6’’ long; style very short. 
In low grounds and waste places, occasional from 
Massachusetts to Virginia and Ohio. Adventive or 
naturalized from Europe. Native also of northern 
Asia. Summer. 
2. Roripa sinuata (Nutt.) A. S. a 
Hitchcock. Spreading Yellow- = 
= ( SB \) V2 
cress. (Fig. 1714.) \ Sah SS 
Nasturtium sinuatum Nutt.; T. & G. FN, A. \ (eS 
\) 
1:73. 1838. ‘ \ i \ 
Roripa sinuata A, S. Hitchcock, Spring FI. SN k 
Manhattan, 18. 1894. 
\\ 
SS 
me 
SKE 
WD 
ys 
Perennial, diffuse, glabrous, the branches pee 
ascending. Leaves oblong, lanceolate, or lp ( (f VS IN (if Z 
oblanceolate, 2/-3’ long, 1%4’-1’ wide, pinna- ip : \\ Was Ye <S 
tifid, the lobes linear or oblong, obtuse, en- Ny \ AQWWIESS 
tire, or sparingly dentate; pedicels slender, 3// a 1 / A SACS 
long; flowers yellow, about 2’ broad; pods oN Nf é 
linear-oblong, sometimes slightly curved: 2 
4//-6’’ long; style slender, 1/’-114’’ long. 2 Si 
Banks of the Mississippi, Minnesota to Mis- Z ( Le 
souri, west to the Sierra Nevada. The eastern 1 f 
forms referred to this species may be specifically 
distinct. Jure-Sept. 
we 
Qi WV 
3. Roripa obtusa (Nutt.) Britton. 
Blunt-leaved Yellow-cress. 
(Fig. 1715.) 
Nasturtium obtusum Nutt.; T. & G. Fl. N. A. 
I: 74. 1838. 
Roripa obtusa Britton, Mem. Torr. Club, 5: 
169. 1894. 
Annual or biennial, diffuse, much 
branched, the branches ascending or erect. 
Leaves oblong or oblanceolate, 2’—4’ long, 
pinnately divided, or pinnatifid, the lobes 
obtuse, repand-toothed, or sometimes entire; 
pedicels 1//-2’’ long; flowers yellow, 1/’ 
broad or less; pods narrowly oblong, or lin- 
ear, 3/’-5’’ long, ascending; style %’’ long. 
fim 
Oo 
In low grounds, Michigan, south to Texas, 
west to the Pacific Coast. April-Aug. 
