CRUCIFER.E. 23 



toothed, on long petioles ; upper ones narrow and sessile. 

 Pods an inch long or more, on ascending pedicels ; beak 

 about J the length of the pod. A common weed in Mani- 

 toba. 



11. IMPLOTAXIS, DC. 



1. D. mura'lis, DC. Branching from near the base. 

 Smooth or sparingly hispid. Leaves oblanceolate, shallowly 

 and bluntly toothed or pinnatifid. Petals pale yellow. 

 Pods over an inch long, on slender spreading pedicels half 

 as long as the pods. Valves 1-nerved. Ballast-heaps, 

 Atl. Prov. 



2. D. tenuifO'lia, DC. Like the last, but the leaves are 

 deeply sinuate-pinnatifid, with narrow lobes. Pedicels of 

 the pods over an inch long. Ballast-heaps, Atl. Prov. 



12. DRABA, DC. WHITLOW-GRASS. 



1. D. inca'na, L. Hoary - pubescent. Flowers white. 

 Leaves lanceolate or oblanceolate to ovate, entire or spa- 

 ringly toothed. Pods oblong to lanceolate, usually straight, 

 on short erect pedicels. Style short or none. Dry rocks. 



Var. arab'isans, Watson, has the pod glabrous, twisted, 

 and tipped with a distinct style. Rocks. 



2. D. nemOPO'sa, L. A small slender plant with leaves 

 about J of an inch long. Flowers white. Leaves oblong, 

 or somewhat lanceolate, hairy, sessile, serrate. Racemes 

 elongated. Pods elliptical-oblong, half as long as the wide- 

 spreading pedicels, pubescent or smooth. Style none. 

 N. W. 



3. D. Carolinia'na, Walt. Flowers white. Stem 1-5 

 inches high. Leaves obovate, entire. Raceme very short. 

 Pods broadly linear, smooth, longer than the ascending 

 pedicels. Style none. Rocks ; Southern Ontario. 



13. AMS'SUM, Tourn. Ai/rssuM. 



A. ealyei'num, L. A dwarf hoary annual, with linear- 

 spathulate leaves. Calyx persistent. Pod _4-seeded, sharp- 

 edged. Rather rare ; abundant at Queenston Heights. 



