228 ORDER 13. CRUCIFER^B. 



1. NASTURTIUM, R. Br. WATER CRESS. (Lat. nasus tortus ; from 

 the effect of these acrimonious plants upon the nose.) Sepals equal at 

 base, spreading; siliqucs subterete, generally curved upwards, some- 

 times shortened so as to resemble a silicic ; valves veinless ; seeds 

 small, lens-shaped, oo, in a double row (0 ). Aquatic plants with 

 pinnate or pinnatifid Ivs. 



* Petals white. Biliques rather long (10 12") v . No. 1 



* Petals yellowf Siliques shortened (4 8"), but longer than the pedicels (a). 



* Petals yellow. Siliques or .silicles (1 6") shorter than the pedicels (b). 



a Leaves pinnate or pinnatifid. l)iff usely branched Nos. 2, 8 



a Leaves lyrate, or merely toothed. Steins erect Nos. 4, 5 



b Petals not longer than the calyx, obscure Nos. 6, 7 



b Petals longer than the calyx, bright yellow EJ os. 8, 9 



1 N. officinale R. Br. ENGLISH WATER CRESS. Lvs. pinnate, Ifts. ovate, sub- 

 cordate, repand; petals white, longer than the calyx. If Brooks and springy 

 places, rare. (Yellow Springs, 0.) Sts. decumbent, thick, branching, 6 12' long. 

 Lfts. 3 7, broad, mostly rounded at base, obscurely toothed, terminal one 

 largest. Pis. corymbed. Siliques hardly 1' long. Occasionally cultivated for 

 salad. May, Jn. \. 



2 N. tanacetifolium Hook. TANSEY-LEAVED. Upper leaf segm. confluent, lower 

 distinct, oblong or roundisli, sinuate-toothed teeth obtuse; pods linear-oblong. (j) 

 Damp soils, Ga. and Fla., W. and N. W. to the Miss. Sts. smooth, diffusely 

 branched from the base, 4 12' high. Hoot Ivs. 2 4' long, narrow, regularly 

 pinnate with 19 15 segm. in the larger plants, the 3 upper segm. often conflu- 

 ent. Fls. minute. Pods 4 8" long, slightly curved, on ped. as long, and 

 tipped with a distinct but short style. Mar., May. 



/3. OBTUSUM. Lfts. mostly distinct, oval, obtuse; pods shorter (3 to 5"), twice 

 longer than pedicel. (N. obtusum, Nutt.) 



3 N. Walter!. Segm. of the Ivs. all distinct, narrow, with a few linear, acute lobes 

 or teeth; pods linear, 14 ? Ga. (Feay and Pond.) and Car. Rt. thick, blackish, 

 with many strong fibres. Lvs. numerous, mostly radical or subcauline, 1 2' 

 long, finely dissected, the terminal segm. 3-lobed. Sts. branched from the base 

 (only?), 3 5' high, puberulent. Fls. minute. Pods slender, about 5" long, 

 ped. half as long ; style distinct. Mar., Apr. (Sisymbrium Walteri Ell.) 



4 N. limosum Nutt. Lvs. lanceolate, toothed, lower ones pinnatified at base 

 (lyrate), upper entire at -base ; pods elliptic-oblong (3 4"). @ Edges of the 

 Miss., La. (Hale.) Glabrous. Sts. erect, simple, branched only at top, 10 15' 

 high. Lvs. all cauline and petiolato, the lower irregularly divided at base, where 

 they touch the water. Rac. several. Fls. minute. Pods on very short pedicels, 

 with styles much shorter. Apr., May. Hardly distinct from the next. 



5 N. sessiliflorum Nutt. Lvs. cuneate-obovate, repandly toothed or sub-entire ; 

 pods linear-oblong (5 6"), subsessile. @ Banks of the Miss. Glabrous. Sts. 

 erect, nearly simple. Lvs. attenuated at base, those of the stem nearly 

 entira Pis. minute. Rac. elongated in fruit, both pods and stigmas almost 

 sessile. Apr. Jn. 



6 N. palustre DC. MARSH CRESS. Glabrous ; Ivs. pinnately lobed, amplexical, 

 lobes confluent, dentate ; rt. fusiform ; pet. as long as the sepals ; silicle spreading, 

 turgid, twice longer than wide. 1{ In wet places. St t 1 2f high, erect, branched 

 above. Lvs. 2 3' long, all more or less pinnatified, with the terminal lobo 

 large, ovate. Fls. numerous, small. Silicle 3" long, pedicels twice as long, often 

 deflexed. Jn. Aug. 



7 N. hispidmn DC. Villous; Ivs. runcinate-pinnatified, lobes obtusety dentate; 

 silicles tumid, ovoid or globular, the pedicels longer, ascending; pet. scarcely as 

 long as the calyx. d) Banks of streams N. H. to Penri. Stem angular, branched, 

 1 3f high, with many paniculate racemes above. Lvs. 3 6' long. Fls. 

 minute. Silicles 1" long, on pedicels 2 3" long and somewhat spreading. Jn. 

 Aug. 



8 N. sylvestre R. Br. WOOD CRESS. Lvs. pinnately divided, segm. serrate or in- 

 cised; pods linear, styk very short Ij. Wet meadows, near Philadelphia (Nutt); 



