POLYGONACEJ2. (BUCKWHEAT FAMILY.) 389 



rough on the margins and veins ; spikes erect, oblong, obtuse, close-flowered ; 

 flowers rose-color ; stamens mostly 8, exserted ; style 2-cleft ; achenium orbic- 

 ular, with the sides concave. Wet places, Georgia, and northward. July- 

 Sept. (1) Stem l-3 high, sometimes nearly smooth. Leaves 2' -4' long. 

 Spikes !'-!' long. Flowei;s much larger than those of the two preceding 

 species. 



* * Slieaths fringed with bristly hairs: achenium 3-angled, or (in No. 5) sometimes 

 lenticular : stamens mostly 8. 



5. P. Persicaria, L. Stem smooth, branching from the base, erect or 

 diffuse ; leaves lanceolate or oblong, obtuse or acutish, the margins and veins 

 roughened ; sheaths short, nearly smooth, fringed with a few short bristles ; 

 spikes short, oblong, obtuse, dense-flowered ; flowers rose-color ; stamens 6 - 7 ; 

 style half 2-cleft ; achenium lenticular or 3-angled, smooth and shining. Low 

 places around dwellings and along roads, Florida, and northward. Introduced. 

 July. Stem l-l high. Leaves 2' -4' long, often with a dark trian- 

 gular spot in the middle. Spikes '- 1' long. 



6. P. acre, Kunth. Stem slender, smooth, creeping at the base; leaves 

 lanceolate, rough on the margins and veins, and, like the white calyx, dotted 

 with pellucid glands ; sheaths smoothish, long-fringed at the throat ; spikes 

 1-3, filiform, loose-flowered ; stamens 8 ; style 3-parted ; achenium 3-angled. 

 (P. punctatum, Ell.} Ditches and margins of ponds, Florida, and northward. 

 July -Sept. }|. Stem 1- 3 long. Leaves 2' - 4' long, very acrid. Spikes 

 2' -3' long. 



7. P. hydropiperoides, Michx. Stem slender, smooth, ascending from 

 a floating or creeping base ; leaves linear or lanceolate, roughened with short 

 rigid hairs on both sides, or only on the margins and veins ; sheaths hispid, 

 long-fringed ; spikes 2-3, linear, rather close-flowered ; calyx pale rose-color, 

 and, like the leaves, glandless ; stamens 8 ; style 3-cleft ; achenium 3-angled. 

 (P. mite, Pers.) Ditches and muddy banks, Florida, and northward. July - 

 Sept. 1J. Stem 2 -3 long. Leaves 2' -4' long, not acrid. Spikes 1'- 2' 

 long. 



8. P. setaceum, Baldw. Stem erect, sparingly branched, smooth below, 

 the upper portion, like the peduncles and lanceolate glandless leaves, rough with 

 appressed hairs ; stipules appressed-hirsute, copiously fringed with long bristles ; 

 spikes filiform, by pairs, loose-flowered ; flowers white, glandless ; stamens 8 ; 

 style 3-cleft ; achenium 3-angled. Low ground, Georgia and Florida. July- 

 Sept. U Stem 2 -3 high. Leaves 3' -5' long. Spikes l'-2' long. 



9. P. hirsutum, Walt. Stem erect, densely hirsute Avith spreading ful- 

 vous hairs ; leaves lanceolate, nearly sessile, rounded at the base, hirsute, partic- 

 ularly on the veins and margins ; sheaths hirsute, copiously fringed ; spikes 

 2-3, linear, erect, rather close-flowered ; peduncles smooth above ; bracts 

 naked ; flowers white, glandless ; stamens 8 ; achenium 3-angled. Pine-barren 

 ponds, Florida to North Carolina. July -Sept. U Stem 2 -3 high. 

 Leaves 2' - 3' long. Spikes 1' long. 



33* 



