558 BRASSICACEAE 
6. R. sylvestris (L.) Druee. Stem ascending or decumbent, 2-7 dm. long: leaf- 
blades often ovate or elliptic, 4-15 em. long, pesa divi ided, the segments 
. lon 
distant, entire or toothed: sepals becoming 2 ng: filaments searcely 
pads than the ip pod slender, 8—15 m 2 short-beaked.—( YELLOW- 
$.)— ground along streams and ante laces various provinces, rarely 
—Wet 
Coastal Plain, Ala. to La., Ill, Ont., Newf., and Va. Nat. of Eu.—Spr.-sum 
7. ARMORACIA Gaertn. Perennial erect herbs with long, pungent roots. 
Leaf-blades coarsely toothed or sometimes a nnatifid. Raceme stiff, with slender 
pedicels. Sepals rather broad. Petals w 
m 
oid. ary 
columnar: stigma capitate. Pod short and 
stout.—About 4 species, Eurasian. 
A. Armoracia (L.) Britton. Stem erect: 
leaf-blades var ious, those of the basal pass 
0 
em. long, gularly erenate, unequally cor- 
date or truncat the Aoi of the 
eauline leaves smaller arsely 
and re 
toothed pa ineised: i: white, obovate, 
6-8 ong: pod 5-7 mm. long, straight. 
[Roripa- Armoracia  (L.) <A. Hitche. 
(HORSERADISH. ) a bi ed thiekets, low grounds, various prance: N of 
Coastal Plain, N. C. to Tenn. and S Can. Nat. of Eu. —Spr. 
8. NEOBECKIA Greene. Perennial aquatie herbs. —— various, the 
immersed ones with finely dissected blades, the emersed o wi maller 
Eus toothed, or pcr blades. Raceme often SV CM pi " PM. 
Petals 4, of a spatul type, white. 
enlarged below: anthers gudittete Ovary 
not stipitate: style slender.  Ovules nu- 
erous. Pod 1-celled, short, turgid.—One 
species. 
1. N. aquatica oe nee hig partly 
immersed, w rsed lea sometimes 
numerous; lad les grannies dissected, 
illary: emersed 
na 
ing: ay tere elliptic a ovate, : 
petals broadly dE ulate, 6-7 : er Bud pod 
lon Nas 
ellipsoid, D ng. [ e la- 
custre A. Roripa americana wh ray) 
Britton] (LAKE RE VON d kes and p streams, various provinces, Fla to 
, Minn., and Que.— 
9. SISYMBRIUM [Tourn.] L. Pond diffuse aquatic herbs wi 
creeping stems. Leaf-blades pinnately divided. Raceme lax. Sepals he 
Petals 4, white, much exceeding the sepals. Stamens mostly 6: anthers ovoid. 
