POLYGONACEAE 379 



long bristles : racemes narrowly cylindric or almost linear, 3-6 cm. long, erect : ocreolae 

 funnelform, 2.5-3 mm. long, oblique, fringed with short bristles : calyx about 2mm. long, 

 flesh-colored or sometimes greenish : sepals oblong or obovate, obtuse or acutish, glandu- 

 lar : stamens 8 : achenes 3-angled, about 3 mm. long, ovoid or broadly oblong, pointed at 

 the apex, black, smooth and shining. [Polygonum hydropiperoides Michx. ] 

 In swamps, New Brunswick to California, Florida and Mexico. Also in Brazil. 



13. Persicaria setacea (Baldw.) Small. Perennial, more or less strigose through- 

 out. Stem erect, 6-11 dm. long, sometimes becoming nearly glabrous, enlarged especially 

 above the nodes : leaf-blades oblong-lanceolate or narrowly lanceolate, 4-18 cm. long, 

 acuminate at both ends, strigose on both sides, or occasionally nearly glabrous, except the 

 midrib and nerves beneath, ciliate, inconspicuously but closely punctate : ocreae 1-1.5 

 cm. long, strigose, fringed with bristles often equalling the body in length : racemes erect, 

 1-6 cm. long, almost linear, loosely flowered : ocreolae funnelform, slightly oblique, 2-2.5 

 mm. long, fringed with bristles, some of the bristles exceeding them in length : calyx 

 about 2 mm. long, white or pink: sepals ovate-oblong, obtuse : stamens 8 : achenes 3-angled, 

 2-3 mm. long, broadly oblong, obovoid or oblong-ovoid, somewhat rhomboidal, thick- 

 tipped at both ends, black, minutely granular and rather dull or slightly shining. [Poly- 

 gonum setaceum Baldw.] 



In swamps, Missouri and North Carolina to Texas, Louisiana and Florida. 



14. Persicaria hirsuta ( Walt. ) Small. Perennial, conspicuously hirsute with red- 

 dish or brown hairs. Stem erect or decumbent and creeping, 3-9 dm. long, becoming 

 woody below : leaf-blades lanceolate, 3-10 cm. long, cordate or subcordate, acute at the 

 apex, the upper ones acuminate, more or less hispid on both surfaces, ciliate, incon- 

 spicuously punctate: ocreae 1-1.5 cm. long, very hispid, fringed with many but rather 

 short bristles: racemes erect, 1.5-6 cm. long, narrow or almost linear, rather loosely 

 flowered, sometimes interrupted : ocreolae funnelform, oblique, 2 mm. long, acute, fringed 

 with a few bristles: calyx 2.5-3 mm. long, white: sepals oblong, obtuse: stamens 8 or 

 fewer : achenes 3-angled, 2 mm. long, broadly obovoid or nearly oblong, short-tipped, 

 black, smooth- and shining. [Polygonum hirsutum Walt. ] 



In swamps or wet soil, Florida and Georgia. Spring to fall. A more slender form with erect stems 

 2-4 dm. long, glabrous or sparingly strigose especially about the nodes, narrowly lanceolate, obtuse leaf- 

 blades 3-6 cm. long, 0.5-1 cm. broad, glabrous except the midrib and a few straggling hairs on the 

 upper and lower surfaces. P. hirsuta glabrgscens (Meisn.) Small, [Polygonum hirsutum glabrescens Meisn.], 

 has been collected at Lake Jamony and Tallahassee, Florida. 



15. Persicaria punctata (Ell.) Small. Annual or perennial, mostly glabrous 

 throughout. Stem erect or ascending, rarely creeping, 3-11 dm. long : leaf-blades varying 

 from lanceolate to narrowly lanceolate, often oblong-lanceolate, 2-16 cm. long, acuminate 

 at both ends, nearly glabrous, conspicuously punctate, often bearing a few short hairs on 

 the midrib, ciliate : ocreae 1-1.5 cm. long, glabrous or sometimes sparingly strigillose, 

 fringed with rather long bristles : racemes linear, 1-6 cm. long, erect, somewhat inter- 

 rupted below, loosely flowered : ocreolae funnelform, 2.5-3 mm. long, fringed with a few 

 short bristles, mostly imbricated : calyx greenish, about 2 mm.!long, conspicuously gland- 

 ular : sepals oblong or ovate, obtuse, punctate : stamens 8 : achenes lenticular and slightly 

 gibbous, or 3-angled, 2-2.5 mm. long, broadly oblong, black, smooth and shining. [Poly- 

 gonum punctatum Ell.] 



In low places or swamps, throughout America except the extreme north and south. Also in the 

 West Indies. Spring to fall. Very variable: > The slender state P. punctata teptostdchya (Meisn.) 

 Small, has much-interrupted racemes and remote ocreolae. Two stout varieties are distinguished : 

 P. punctata robustior Small, inhabiting swamps on the eastern side of the American continent, has 

 larger leaf-blades, and 3-angled achenes 3-4 mm. long ; P. punctata ccilidta Small, occurring in New Jer- 

 sey, Tennessee and Mexico, has large leaves like the next preceding variety, naked ocreae, reddish 

 purple inflorescence, and a 3-angled achene about 3.5 mm. long. 



16. Persicaria minor ( Huds. ) Opiz. Annual, dull-green, scurfy throughout. Stem 

 lax, diffuse, 3-5 dm. long, sometimes procumbent and creeping : leaf-blades varying from 

 lanceolate to linear or sometimes oblong, 2-8 cm. long, unsymmetrical and often scythe- 

 shaped, ciliate : ocreae 1 cm. long, sparingly strigose and fringed with a few short bristles : 

 racemes linear, 1-5 cm. long, lax, few-flowered, more or less interrupted at the base : 

 ocreolae funnelform, 3 mm. long, somewhat oblique, fringed with short bristles : 

 calyx greenish, 2.5-3 mm. long : stamens 8 or fewer : achenes lenticular, nearly 2 mm. 

 long, broadly oblong, Conspicuously biconvex or 3-angled and narrowly ovoid-oblong, 

 black, smooth and shining. [Polygonum minus Huds. ] 



In low grounds, Louisiana. Also in Chili. Introduced from Europe. 



17. Persicaria Hydropiper (L. ) Opiz. Annual, glabrous, usually bright green. 

 Stem erect or assurgent, 2-6 dm. long, lax, sometimes red or reddish : leaf-blades varying 

 from ovate to oblong-lanceolate, sometimes lanceolate, 1.5-9 cm. long, acute at both ends or 



