POLYGONUM POLYGONACE 4 579 
ovate spicate raceme: calyx rose-color, about 2 lines long, 5-parted to below 
the middle: stamens 5, exserted: style about 2 lines long 2-cleft: achenes 
lenticular, orbicular-oblong or obovoid. In ponds and wet places, Alaska 
to California and the Atlantic States: also Europe and Asia. 
P. Hartwrightii Gray Proc. Am. Acad viii, 294 Perennial: more or 
less hispid throughout, except when growing in water: stems creeping and 
ascending, or suberect, 1-3 feet long, leafy: leaves oblong to narrowly lan- 
ceolate, 3-9 inches long, obtuse or acutish at both ends, short-petioled or 
sessile: ocreae cylindric, 6-9 lines long, with a more or iess spreading rim, 
fringed at the summit with short bristles: flowers numerous, in a dense 
oblong to conic spicate raceme: calyx rose-color, about 2 lines long, 5-parted 
to below the middle: stamens 5, exserted: achenes lenticular, oblong. In 
moist places, Alaska to California and the Atlantic States. 
P Muhlenbergii Watson Proc. Am. Acad. xiv, 245. Perennial : glab- 
rous or strigose throughout: stems more or less creeping in wet places, the 
distal end erect, 12-30 inches long, mostly simple, leafy, enlarged at the 
joints: leaves narrowly to broadly lanceolate, 2-10 inches long, acute or 
acuminate, rounded or narrowed to cordate at base, all petioled: ocreae 
cylindric, 12-18 lines long. when young clasping the stem, becoming loose 
and inflated near tiie base in age: flowers in 1-3 terminal linear densely- 
flowered racemes 2-5inches long: calyx dark rose-color to pink, 2lines long, 
5-parted tothe middle: stamens 5, exserted: style 2-cleft, exserted: achenes 
lenticular, broadly obovoid. In water or wet places, throughout North 
America. 
P. wapatairotium L. Sp. 360. Annual: glabrous or more or less pu- 
bescent throughout: stem stout, mostly erect, 1-2 feet high, branched 
above or throughout, sometimes nearly simple, thickened at the joints: 
leaves broadly to narrowly lanceolate, 2-10 inches long, attenuate toward 
the apex frum the broadest part, acuminate at base, ciliate, inconspicuous- 
ly punctate, short-petioled: ocreae cylindric, 6-12 lines long, loose, striate 
or ribbed, slightly ciliate when young: peduncles and pedicels more or less 
glandular: racemes 1-5, inaterminal panicle, denselv flowered, 1-+ inches 
long, mostly drooping: calyx flesh-color to white, 5-parted to below the 
middle: stamens 6, included: achenes lenticular or trigonous, oblong or 
ovoid. In moist places, throughout temperate North America: introduced 
from Europe. 
Var. incanum Koch Syn. Fl. Germ. 711, Small and slender: stem 
erect, 2-12 invhes high, simple or branched: leaves lanceolate to ovate or 
oblong, glabrous above, white tomentose beneath, short-petioled or sub- 
sessile: racemes oblong, 6-12 lines long, erect: achenes lenticular, ovoid. 
In damp places, Oregon and Washington to the Atlantic States. 
P. nodosum Persoon Syn. i, 440. Annual: stem stout, erect, 1-4 feet 
high, red or reddish with purple spots and dark rings, naked, branched: 
leaves rather narrowly lanceolate, attenuate upward from near the base 
and acuminate, cuneate at base and shortly petioled, somewnat scabrous 
with short prickly hairs on the midribs and margins: ocreae cylindric, 
8-12 lines long, strongly ribbed: racemes axillary and terminal, oblong 
and erect or often linear and nodding, an inch long or more: flowers white 
to light rose-color, about a line long: stamens 6, included: style 2-parted, 
included: achenes lenticular, broadly oblong or ovoid. Throughout North 
America. 
P. Pennsylvanicum L. Sp. 362. Annual: glabrous below, pubescent 
and glandular above: stem erect, 1-3 feet high, simple to much branched: 
leaves from narrowly to broadly lanceolate, 2-10 inches long, ciliate, the 
midrib prominent on the lower side, acuminate at base, short-petioled : 
ocreae cylindric or funnelform, 6-9 lines long: racemes panicled, oblong- 
eylindric, 1-3 inches long, erect, dense; calyx pink or light purple, 1-2 
