TuRRiTis. XIII, • i; r< 'iri-.R/i' :o. 



1. N. OFFICINALE. R.Br. (Sisymbrium Nast. Z.i7i7j.) English Water Cress. 

 Lws. pinnate; Ifts. ovate, subcordate, repand; pet. white, longer than the 



calyx.— '2J. Brooks and ponds. Stems decumbent, If long, thick, with axillary 

 branches. Leaves of 3— 7 leaflets; leaflets broad, often cordate, rather acute, 

 obtusely toothed, terminal one largest. Flowers corymbed. Siliques less than 

 1' long. Jn. — It is beginning to be cultivated in the vicinity of our- cities as a 

 salad. ^ j;, 



2. N. AMPHiBiCM. R. Br. (Sisjanbrium. Linn.) Amphibims Water Cress. 

 Lvs. oblong-lanceolate, pinnatifid or serrate ; rt. fibrous ; pet. longer than 



the calyx; siUque elliptical, acute at base, tipped with the mucronate style. — 

 % Banks of the Mohawk, Dr. Robhins. Rare. Stem 1— if high, furrowed, 

 l^eaves variable, immersed ones pinnatifid or pectinate, upper ones serrate. 

 Flowers yello\v, minute, in a long, dense raceme. Silique half as long as the 

 spreading or reflexed peduncle, pointed with the short style. Jn. Jl. 



3. N. PALUSTRE. DC. Marsh Water Cress. 



Lvs. pinnately lobed, amplexicaul, lobes confluent, dentate, .smooth ; H. 

 fusiform ; pet. as long as the sepals ; sUtquc .spreading, turgid, obtuse at each 

 end. — 'ZL In wet places. Stem 1 — 2f high, erect, branched above. Leaves 2 — 3' 

 long, all more or less pinnatifid, smooth, except a few cilise at base. Flowers 

 numerous, minute, yellow. Silique 3 — 4" long, on pedicels of equal length. 

 Ju. — Aug. 



4. N. HispiDUM. DC. (Sisymbrium. Poirei.) Hispid Water Cress. 



St. villous ; Irs. somewhat villous, runcinate-pinnatifid, lobes rather ob- 

 tusely dentate ; siliques (rather silicles) ovate, tumid, pointed with the style, 

 scarcely more than half as long as the pedicels; pet. scarcely as long as the 

 calyx. — %. Banks of streams, Walpole, N. H., Conn, to Penn. Stem angular, 

 branched, 1 — 3f high, with many paniculate racemes above. Leaves 3 — 6' 

 long. Flowers minute, yellow. Silicles 1" long, on pedicels 2 — 3" long and 

 somewhat spreading. 



5. N. NATAN.S. DC. p. AmerLca7ium. Gray. Floating Water Cress. 

 Emcrsed lis. serrate, oblong-linear, imdivided, immersed ones doubly 



pinnatifid, with capillary segments ; pet. twice as long as the calyx ; siliqves 

 obovate, twice as long as the style. — Tj. fn water. Can. and U. S. Stem long, 

 submerged. Flowers white, middle size. Jl. 



6. N. SYLVESTRE. (Sisymbrium vulgare. Pers.) Creeping Water Cress. 

 Lvs. pinnately divided, segments lanceolate, incisely serrate ; pet. longei 



than the calyx ; siliques oblong, torulose ; sty. very short. — Banks of the Dela- 

 ware near Philadelphia. Nuttall. ^ 



13. BARBAREA. R. Br. 



in honor of St. Barbara, who discovered (what no one has since perceived) its medicinal virtues. 



Sepals erect, subequal at base ; silique columnar, 2 — 4-cornered ; 

 valves concave-earinato; seeds in a single series ; 0=. — -Lvs. lyratel^ 

 pimiatifid. Fls. yellow. 



B. VULGARIS. R. Br. (Ert-simum Barbarea. Linn.) Winter Cress. 



Lower lvs. lyrate, the terminal lobe roundish, ".tpper ones obovate, pin- 

 natifid at base, crenate or repand-uentate ; siliques obscurely 4-cornered. -% In 

 old fields, also brook-sides. Northern States, W. to Oregon, common. Whole 

 plant glabrous. Stem furrowed, l—2f high, branching above. Leaves 1—3 — 4' 

 long, dark green, shining, on clasping petioles, the terminal lobe 1—1 J' diam., 

 upper ones sessile, all with obtuse teeth. Flov,rers on pedicels i' long, in ter 

 minal racemes. Siliques slender, f long, curved upw^ds^ May, Jn. 



14. TURRITIS. Dillon„ 



Lat. tvrritis, turreted j from the pyramidal fonMBK plant. 



Sepals erect, converging ; petals erect ; silique^ong, linear, 2-edged j 

 Valves plane; seeds in a double series, 0==. — Fls. cyanic. 



