580 POLYGONACEAL POLYGONUM 
lines long, 5-parted to the middle: stamens 8 or fewer, included: style 
2-parted to about the middie: achenes lenticular, flat, broader than high. 
Idaho to the Eastern States. 
P. Perrsicarra L. Sp. 361. Annual: stem erect or sometimes spread- 
ing, 8-20 inches high, simple or branched: leaves lanceolate to linear- 
lanceolate, 1-8 inches long, acuminate at both ends, entire or sometimes 
erose, conspicuously punctate, nearly smooth except the more or less his- 
pid midrib and nerves, short-petioled or nearly sessile, generally with a 
dark triangular or lunate spot in the middle: ocreae cy!ndric or funnelform, 
6-9 lines long, conspicuously fringed with short bristles: racemes 1-5, in 
terminal panicles, oblong or ovoid, 6-18 lines long, mostly erect, densely- 
flowered: calyx pink to purple or greenish, 5-cleft to the middle, the seg- 
ments obtuse: stamens generally included: style 2- or 3-parted. included: 
achenes broadly ovoid, pointed. In waste places throughout North and 
South America: naturalized from Europe. 
P. hydropiperoides Michx. Fl. i, 236. Perennial, often tinged with 
red throughout: stems erect, or the base decumbent and creeping, 1-3 feet 
high, simple or branched above, enlarged at the joints: leaves lanceolate to 
linear-lanceolate, 2-6 inches long, glabrous or strigillose, acute at both 
ends, ciliate, short-petioled : ocreae cylindric or funnelform, 6-12 lines long, 
loose, fringed with long bristles: racemes almost linear, 1-3 inches long, 
erect, more or less interrupted: calyx about a line long, flesh-color, or 
greenish, 5-parted to below the middle, the segments oblong or obovate: 
stamens 8, included style short, 3-parted, at length exserted: achenes tri- 
quetrous, ovoid or broadly oblong. In ponds and wet places, Washington 
to California and the Atlantic States. 
P. Hydropiper L. Sp. 361. Annual: glabrous: stems erect or assur- 
gent, 8-24 inches high, simple, or branched throughout: leaves ovate to 
lanceolate, 1-5 inches long, acute or acuminate at both ends, ciliate, un- 
dulate or slightly crisped, short-petioled: ocreae cylindric, 3-6 lines long, 
becoming somewhat funnelform and oblique fringed with long bristles, 
often bearing 1 or 2 flowers within, racemes numerous, axillary and ter- 
minal, 1-3 inches long rather loosely flowered and much interrupted, usual- 
ly drooping: calyx greenish to red or white, 3-5 parted, the segments 
rather narrowly oblong: stamens 4, sometimes 6, included: style 2-3-cleft 
to near the base: achene lenticular or triquetrous, broadly oblong to 
onbicular: In damp places, throughout temperate North America and 
urope. 
SuBGENus tv, AvicuLARIA Meisn. Monog. Polyg. 85. Annual 
or perennial plants with the leaves all cauline, the petioles artic- 
ulated at the junction of the ocreae; the upper ones reduced to 
foliaceous bracts. Ocreae membranaceous and usually hyaline, 
funnelform, oblique, 2-parted, at length lacerate. Inflorescence 
consisting of axillary clusters either widely separated or crowded 
into aterminal raceme. Calyx 5-parted. Stamens mostly 8. 
Style 3-parted or wanting. Achenes triquetrous. Cotyledons in- 
cumbent. , 
i itd Suffruticose smooth perenniais with brown stems and loose scaly 
ark. 
P. paronychia Cham. & Scblecht. Linn. iii, 51. Bright green and 
glabrous throughout: stems prostrate or ascending, 6-18 inches long, dif- 
fusely branched: leaves oblong to oblong-lanceolate, apparently linear or 
linear-lanceolate on account of the strongly revolute margins, 3-5 lines 
long, scattered along the branches and crowded in subspicate clusters at 
