190 COMMON CANADIAN WILD PLANTS. 



Var. ineama'tum, Watson, has the spikes more slender 

 and elongated, nodding. 



Var. inea'num, Koch, is 6-12 inches high, with small 

 leaves more or less flocculent-hoary underneath, and short 

 spikes. Chiefly eastward and N. W. 



6. P. Pennsylvan'ieum, L. Sheaths not fringed. Stem 

 1-3 feet high, the upper branches and the peduncles bristly 

 with stalked glands. Spikes thick, erect. Stamens 8. Achene 

 flat. Low open grounds. 



7. P. Persiea'ria, L. (LADY'S THUMB.) Sheaths with a 

 somewhat ciliate border. Stem nearly smooth, a foot or more 

 in height. Leaves with a dark blotch on the middle of the 

 upper surface. Spikes dense, erect, on naked peduncles. 

 Stamens 6. Achene flat or 3-angled, according as the stig- 

 mas are 2 or 3. Very common near dwellings in moist 

 ground. 



8. P. ampMb'ium, L. (WATER PERSICARIA.) Spike of 

 flowers dense, oblong, showy, rose-red. Stem floating in 

 shallow water or rooting in soft mud, nearly glabrous. 

 Leaves long-petioled, often floating. Sheaths not bristly- 

 fringed. Stamens 5. Stigmas 2. In shallow water, mostly 

 northward. 



9. P. Muhlenberg'ii, Watson, differs from the last in 

 being rough with oppressed hairs all over. Ditches. 



10. P. Hartwright'ii, Gray, is distinguished from P. 

 amphibium by its foliaceous and ciliate sheaths. Muddy 

 margins of ponds and lakes. 



11. P. hydPOpiperoi'des, Michx. (MILD WATER-PEPPER.) 

 Stem slender, 1-3 feet high , in shallow water. Leaves narrow, 

 roughish. Sheaths hairy and fringed with long bristles. 

 Spikes slender, erect, pale rose-coloured or whitish. Stamens 

 8. Stigmas 3. Achene 3-angled. In shallow water. 



12. P. acre, H.B. K. (WATER SMARTWEED.) Sheaths 

 fringed with bristles. Leaves transparent-dotted. Stem root- 

 lag at the decumbent base, 2-4 feet high, in shallow water 

 or muddy soil. Leaves narrow, taper-pointed. Spikes 



