78 POLYGONACEAE 



Var. incamatum (Ell.) S. Wats. Much larger, often 5 high : leaves 

 often 8' long and spikes 2 / -3 / long, somewhat nodding. Common in open 

 moist ground. 



3. P. Pennsylvanicum L. Like the last, but peduncles and pedicels 

 very glandular, glabrous below : spikes oblong, dense, I'-S' long : stamens 

 8. Very abundant in low grounds. 



4. P. longistylum Small. Resembles P. Pennsylvanicum, but the spikes 

 are longer (1/-4 7 long) and less dense, the calyx is larger, and the styles 

 are long-exserted. Low grounds near Atherton. Local. 



5. P. Fersicaria L. Peduncles and pedicels not glandular and ochreae 

 fringed with short bristles. Otherwise closely resembles P. Pennsylva- 

 nicum. Frequent in waste places. July-October. 



6. P. hydropiperoides Michx. Perennial, l-3 high, glabrous or stri- 

 gillose : leaves narrowly lanceolate : ochreae fringed with long bristles : 

 spikes erect, slender and usually interrupted below : achene sharply 

 triangular. Wet prairies near Lake City and Sibley. Locally common. 

 July-October. 



7. P. Hydropiper L. Annual, l-2 high, smooth : leaves lanceolate, 

 punctate : ochreae fringed with short bristles : spikes nodding, slender 

 and interrupted : achene triangular or lenticular : stamens 4 or 6. In 

 waste places. Not uncommon. July-September. 



8. P. punctatum Ell. Annual or perennial, l-4 high, smooth : 

 leaves lanceolate, punctate : ochreae fringed with long bristles : spikes 

 erect, loosely flowered : achene triangular or lenticular. Rather common 

 in wet woods. 



Var. leptostachyum (Meisn ) Small. Plant smaller: spikes much 

 interrupted and more loosely flowered. Very common in damp woods. 



9. P. orientate L. 3-8 high, hispid : leaves broadly ovate, acumi- 

 nate : ochreae short-ciliate : spikes numerous, dense and finally droop- 

 ing : flowers large, rose-colored. Rarely escaped from gardens near In- 

 dependence, Lone Jack and Adams. August-October. 



10. P. Virginianum L. Annual, 2-5 high, nearly smooth, but 

 ochreae strigose: leaves ovate, acuminate: spikes very long, slender and 

 interrupted : flowers greenish-white. Common in rich woods. August- 

 October. 



11. P. aviculare L. Prostrate and widely spreading : leaves oblong to 

 lanceolate, acutish, 3 // -10 // long : ochreae silvery : flowers small : style 

 3-parted to near the base : stamens 5-8. Abundant in waste places. 



Var. littorale (Link. ) Mackenzie & Bush, n. comb. Leaves obtusish, 

 and style 3-parted at the base. Common in waste places. (P. litlorale 

 Link. ) 



12. P. erectum L. Stout, erect, l-2 high: leaves oval to oblong, 

 6 // -20 // long, rather obtuse : stamens usually six : achene included or 

 almost so. Common in woods and waste grounds. August-October. 



