64 CRUCIFER^E. (MUSTARD FAMILY.) 



III. LOMENTACEiE. Pod articulated, separating across into joints. 



Tribe VII. CAKHiIBTE.aS. Cotyledons plane and accumbent, as in Tribe 1. 



19. Cakile. Pod short, 2-jointed : the joints 1-celled and 1-seeded. 



Tribe "VIII. RAPHANEjE. Cotyledons conduplicate and incumbent, as in Tribe 3. 



20. Raphanus. Pod elongated, several-seeded, transversely intercepted. 



1. NASTURTIUM, R.Br. Water-Cress. 



Pod a short silique or a silicle, varying from oblong-linear to globular, terete 

 or nearly so. Seeds small, turgid, marginless, in 2 irregular rows in each cell 

 (except in No. 2). Cotyledons accumbent. — Aquatic or marsh plants, with 

 yellow or white flowers, and commonly pinnate or pinnatifid leaves, usually 

 glabrous. (Name from Nasus tortus, a convulsed nose, alluding to the effect of 

 its pungent qualities.) 



§ 1. Petals ivhite, twice the length of the calyx: pods linear: leaves pinnate. 



1. N. officinale, R.Br. (True Water-Cress.) Stems spreading and 

 rooting; leaflets 3-11, roundish or oblong, nearly entire; pods (6" -8" long) 

 ascending on slender widely spreading pedicels. % — Brooks and ditches : 

 escaped from cultivation. (Nat. from Eu.) 



§ 2. Petals yellow or yellowish, seldom much exceeding the calyx : pods linear, oblong, 

 or even ovoid or globular : leaves mostly pinnatijid. 



* Perennial from creeping or subterranean shoots : flowers rather large, bright yelhw. 



2. N. sylvestre, R. Br. (Yellow Cress.) Stems ascending; leaves 

 pinnate] y parted, the divisions toothed or cut, lanceolate or linear; pods {\' long) 

 on slender pedicels, linear and narrow, bringing the seeds into one row ; style 

 very short. — Wet meadows, Massachusetts to Virginia: rare. (Nat. from Eu.) 



3. N. sinu&tum, Nutt. Stems low, diffuse; leaves pinnately cleft, the 

 short lobes nearly entire, linear-oblong; pods linear-oblong (4" -6" long), on 

 slender pedicels ; style slender. — Banks of the Mississippi and westward. June. 



* * Annual or biennial, rarely perennial? ivith simple fibrous roots : flowers small or 



minute, greenish or yellowish : leaves somewhat lyrate. 



4. "N. sessilifldrum, Nutt. Stems erect, rather simple; leaves obtusely 

 incised or toothed, obovate or oblong ; flowers minute, nearly sessile ; pods elon- 

 gated-oblong (5" -6" long), thick ; style very short. — W. Illinois to Tennessee 

 and southward. April -June. 



5. N. obttisum, Nutt. Stems much branched, diffusely spreading ; leaves 

 pinnately parted or divided, the divisions roundish and obtusely toothed or rcpand ; 

 flowers minute, short-pedicelled ; pods longer than the pedicels, varying from linear- 

 oblong to short-oval ; style short. — With No. 3 and 4. 



7. N. pallistre, DC. (Marsh Cress.) Stem erect; leaves pinnately 

 cleft or parted, or the upper laciniate ; the lobes oblong, cut-toothed ; pedicels 

 about as long as the small flowers and mostly longer than the oblong, ellipsoid, or 

 ovoid pods; style short. — Wet places or in shallow water ; common. June- 

 Sept. — Flowers only l"-l£" long. Stems l°-3° high. — The typical form 

 with oblong pods is rare (W. New York, Dr. Sartwell). Short pods and hirsute 

 stems and leaves are common. Var. hisfiduji (N. hispidum, DC.) is a form, 

 with ovoid or globular pods. (Eu.) 



