MEMOIRS FKOM THE DEPARTMENT OP BOTANY OF COLUMBIA COLLEGE. 89 



.3-.4 mm. long, two-parted or three-parted to the base; achenes lenticular, biconvex, 

 slightly gibbous, or triquetrous, 2.5 mm. long, broadly-oblong, narrower when triquetrous, 

 thick-pointed, black, smooth and shining. 



From Ottawa to Cahfornia, south to Colombia, Brazil and Paraguay. Also in the 

 West Indies. 



Polygonum punctatum leptostachyum (Meisner) Small. 



Polygonum acre var. leptostachyum Meisner in DC. Prodr. 14: 108 (1856). 



Polygonum punctatum var. leptostachyum Small, Bull. Torr. Club, 19: 356 (1892). 



Slender and somewhat smaller than the species. Stem erect, 3-4 dm. long, slender; 

 leaves mostly lanceolate, 3-8 cm. long, .5-2 cm. broad; racemes very slender, 4-20 cm. 

 long, much interrupted except near the summit ; ocreolae distant, not imbricated. 



Vermont to California, south to Florida and Mexico. Also in New Granada. 



Polygonum punctatum robustior Small. 



Polygonum -punctatum robustior Small, Bull. Torr. Club 21 : 477 (1894). 



Robust, of a rather dull green color. Stem erect, 4-7 dm. long, often with a creep- 

 ing base; leaves oblong or lanceolate, 3-17 cm. long, .5-4 cm. broad, the lower surface 

 paler than the upper; ocreae 1-1.5 cm. long, somewhat strigillose, fringed Avith long bris- 

 tles, loose, inflated about the nodes ; ocreolae continguous or imbricated, entire ; pedicels 

 3-4 mm. long ; achene triquetrous, 3-4 mm. long, broadly oblong, smooth and shining. 



In the Atlantic States from Massachusetts to Florida, Central America and north- 

 eastern South America. 



Polygonum punctatum eciliatum Small. 



Polygonum punctatum var. eciliatum Small, Bull. Torr. Club 20: 214 (1893). 



ilather stout and more robust than the species, less scurfy throughout. Stem erect, 

 6-9 dm. long, much branched; leaves lanceolate or oblong-lanceolate, 3-12 cm. long, 

 .5-3 cm. broad, less punctate than in the normal form; ocreae 1-2 cm. long, loose, 

 bearing no bristles; racemes 3-6 cm. long, these as Avell as the adjacent part of the in- 

 florescence of a dark reddish-purple color; achene triquetrous, 3.5 mm. long, broadly 

 oblong, finely but plainly reticulated. 



Tennessee and Mexico. 



