114 CRUCIFERACEAE (MUSTARD FAMILY) 



G. Leaflets petiolulate, roundish; seeds 8-20. W. C. C. oligosperma 



GG. Leaflets of the stem leaves tending to be decurrent along the leaf axis, 

 lateral ones oblong to oval; seeds 20-40. W. C. E. 



C. pennsylvanica (PENNSYLVANIA BITTER CRESS) 



DENTARIA (TOOTHWORT) 



Perennial; rhizome horizontal; stems erect, leafless below. Leaves 

 palmately laciniate or 3-divided, petioled. Flowers white or rose or purple, 

 in corymbs or short racemes. Pod linear, straight, flat, without stipe, 

 dehiscent. Seeds i row in each cell, flat, wingless. (L. dens = a tooth ; 

 referring to the toothlike projections of the rootstock.) 



A. Stem leaves of 3 petiolulate leaflets; basal leaves entire or with 3 leaflets. U. 



D. californica 



AA. Stem leaves either not completely divided into leaflets or these not petiolulate. 

 B. Basal leaves round-cordate, crenate or sinuate; racemes few-flowered. W. C. 



D. tenella (DELICATE TOOTHWORT) 



BB. Basal leaves parted or divided into 3-5 segments; racemes densely many- 

 flowered. U. C. E. D. macrocarpa 



PHYSARIA (TWIN POD) 



Perennial, low, stellate-hairy. Leaves mostly entire. Flowers in ter- 

 minal racemes. Petals longer than the sepals. Style filiform. Pod mem- 

 branous, stellate-pubescent; partition narrow; cells subglobose, several- 

 seeded. Seed not margined. (Gk. physa = a bladder ; the pod is inflated.) 



A. Mature pod much inflated, 1.2-1.7 cm. wide, its upper sinus acute. E. 



P. didymocarpa 



AA. Mature pod but little inflated, its upper sinus shallow and rounded. 

 B. Pedicels 6 mm. long; pod 5-8 mm. wide, its partition ovate. E. P. geyeri 



BB. Pedicels 12 mm. or more long; pod 10-20 mm. wide, its partition narrowly 

 linear. E. P. oregana 



LESQUERELLA (BLADDER POD) 



Annual or perennial, low. Leaves entire or repand-dentate. Petals 

 spatulate to obovate, entire. Valves of pod veinless ; partition hyaline, 

 veined from apex to middle. Seeds rounded, flat. (Diminutive, honor 

 of L. Lesquereux, an American bryologist.) 



A. Hairs stellate; pod obovate, its cells 2-ovuled. E. L. douglasii 



AA. Hairs not stellate; pod oval, its cells 4-ovuled. E. L. occidentalis 



CAMELINA (FALSE FLAX) 



Annual, erect. Leaves entire to pinnatifid. Sepals somewhat colored. 

 Petals spatulate to obovate, clawed. Valves of pod strongly convex; 

 partition obovoid, persistent. Seeds in 2 rows in each cell, many, wingless. 

 (Gk. chamai = a dwarf, linon = flax.) 



A. Pod 6-7 mm. wide; plant glabrous or nearly so. W. E. C. satlva 



AA. Pod 4-5 mm. wide; plant pubescent at least below. E. C. microcarpa 



