378 POLYGONACEAE 
blades varying from broadly lanceolate to narrowly lanceolate, sometimes oblong-lanceolate, 
5-20 cm. long, attenuate to the apex from the broadest part, acuminate at the base, ciliate, 
inconspicuously but thickly punctate, the petiole and midrib slightly hispid, the latter and 
the lateral nerves prominent beneath: ocreae 1-2 cm. long, striate or ribbed, brittle, 
slightly ciliate when young, at length eciliate: racemes linear, 2-8 cm. long, mostly 
drooping, dense: ocreolae funnelform, 2 mm. long, very oblique, acute: calyx flesh- 
colored or whitish, 2-2.5 mm. long: stamens 6: achenes lenticular, 2-2.5 mm. long, very 
broadly oblong or broadly ovoid, biconcave, brownish or black, slightly granular but 
usually shining. [Polygonum lapathifolium L. ] 
In waste places, throughout North America except the extreme north, Mexico, Central America 
and the West Indies. Apparently mainly introduced from Europe. 
8. Persicaria ségeta (H.B.K.) Small. Perennial, pubescent or glandular about 
the inflorescence. Stem erect, 4-8 dm. long, enlarged at the nodes: leaf-blades nar- 
rowly lanceolate, 6-16 em. long, acuminate at both ends, sometimes undulate and slightly 
crisped, glabrous, except occasional short stout hairs on the midrib, and the ciliate margin ; 
petioles about 1 em. long: ocreae 1-1.5 cm. long, those on the lower part of the stem 
glabrous, the upper ones pubescent or glandular, fringed with short bristles: racemes 
erect, 2-4 cm. long, cylindric, rather loosely flowered: ocreolae funnelform, 2-2.5 mm. 
long, oblique, coriaceous with a somewhat membranous edge: calyx 2-2.5 mm. long: 
sepals oblong, obtuse: stamens 6 or 7: achenes lenticular, 2.5 mm. long, ovoid, usually 
somewhat plano-concave, rather long-tipped, dark brown, minutely granular, dull. [Poly- 
gonum segetum H. D. K. ] 
In low grounds, Louisiana, Mexico and the West Indies. Also in Colombia. 
9. Persicaria persicarioides (H.B.K.) Small. Perennial, nearly glabrous or 
strigillose. Stem erect or decumbent and creeping, 3-7 dm. long: leaf-blades lanceolate 
or often linear-lanceolate, 3-20 cm. long, acuminate at both ends, glabrous or pubescent 
with scattered hairs, especially on the midrib, ciliate, punctate, short-petioled or subsessile : 
ocreae 1-2 cm. long, glabrous or sparsely strigillose, inconspicuously fringed with short 
bristles : racemes erect, 2-6 cm. long, narrowly oblong or linear, rather loosely flowered : 
ocreolae funnelform, oblique, 3 mm. long, fringed with a few short bristles or naked, often 
glandular or scurfy about the summit : calyx 2-3 mm. long, rose-color tinged with green: 
sepals oblong, obtuse: stamens 8 or fewer: achenes lenticular, biconvex and more or less 
gibbous, or 3-angled, 2.5-3 mm. long, narrowly ovoid or sometimes broadly oblong, rather 
long-tipped, black, somewhat granular but shining. [Polygonum persicarioides H.B.K. ] 
On plains or prairies, Nebraska, Texas, New Mexico and Mexico. Alsoin South America. 
10. Persicaria Persicaria (L.) Small. Annual, glabrous or puberulent. Stem erect or 
sometimes spreading, 2-8 dm. long : leaf-blades varying from lanceolate to linear-lanceolate, 
2-18 cm. long, acuminate at both ends, entire or sometimes eroded, often somewhat ciliate, 
conspienously punctate, generally with a dark triangular or lunar spot in the middle: 
ocreae 1-1.5 em. long, nearly glabrous or with short hairs on the ridges, usually conspicu- 
ously fringed with short bristles : racemes oblong or ovoid, 1-3 em. long, 0.5-1 em. thick, 
mostly erect, densely-flowered : ocreolae funnelform, 1.5-2 mm. long, oblique, smooth or 
nearly so, fringed with short bristles: calyx about 1.5 mm. long, varying from pink to 
dark purple or sometimes red or greenish : sepals obtuse: stamens generally 6: achenes 
lenticular, biconvex, often gibbous, or 3-angled, 2-2.5 mm. long, broadly ovoid, pointed, 
black, smooth and shining. [Polygonum Persicaria L. ] \ 
In waste places, throughout temperate and tropical North and South America. Naturalized from 
Europe. LADY's THUMB. 
11. Persicaria Opelousana (Ridd.) Small. Perennial, slender and rather strict. 
Stem erect or ascending, 3-9 dm. long, glabrous, becoming woody below : leaf-blades vary- 
ing from linear-lanceolate to linear, 3-10 em. long, glabrous or with a few stout hairs espe- 
cially on or about the midrib, ciliate: ocreae 1-1.5 cm. long, strigose, fringed with long 
bristles : racemes linear, 1.5-4 cm. long, erect, not densely flowered : ocreolae funnelform, 
2.5 mm. long, slightly oblique, conspicuously fringed with long bristles: calyx 1-1.5 mm. 
long, white: sepals oblong, obtuse: stamens 8 or fewer: achenes 3-angled, or rarely 4- 
angled, about 2 mm. long, varying from broadly ovoid to obovoid, black, smooth and 
shining. [Polygonum Opelousanum Ridd. ] 
In swamps, southern Missouri and the Indian Territory to Louisiana, Texas and Mexico. 
_ 12. Persicaria hydropiperoides (Michx.) Small. Perennial, glabrous or sometimes 
slightly strigillose, often tinged with red throughout. Stem erect or the base decumbent 
and creeping, 3-9 dm. long: leaf-blades lanceolate or oblong-lanceolate, sometimes linear-_ 
lanceolate, 4-13 cm. long, acute at both ends, ciliate, papillose on the lower surface, short- 
petioled, the midrib clothed with short hairs: ocreae 1-1.8 cm. long, strigose, fringed with 
