POLYGONACEAE. 
3. Polygonum Hartwrightii A. Gray. 
Hart Wright’s Persicaria. (Fig. 1320.) 
bie Aa Hartwrightii A, Gray, Proc. Am. Acad. 
: 294. 1870. 
ees by rootstocks, more or less hispid 
throughout; stem ascending, decumbent or erect, 
6’-2° long, many-jointed, grooved, usually rather 
stout. Leaves lanceolate, oblong-lanceolate or ob- 
long, 3-6’ long, obtuse or subacute at the apex, 
short-petioled or sessile; ocreae cylindric, varying 
from one-half as long to as long as the internodes, 
the limb abruptly spreading, fringed with short 
bristles; racemes usually solitary, dense, %4’—1’ 
long, oblong; calyx rose-colored, 5 parted; sta- 
mens 5, exserted; style exserted, 2-cleft to be- 
yond the middle; achene oblong, biconvex, lenti- 
cular, black, smooth, shining. 
In swamps or moist soil, Hudson Bay to Oregon, 
south to southern Pennsylvania, Kansas, Nevada and 
Lower California. June-Aug. 
4. Polygonum emérsum (Michx.) Britton. Swamp Persicaria. (Fig. 1321.) 
Polygonum amphibium var. emersum Michx. Fl. Bor. \ 
Am. I: 240. 180. 
3- 
P. Muhlenbergii S. Wats. Proc. Am. Ac. 14: 295. _ 1879. 
Polygonum emersum Britton, Trans. N. Y. Acad. Sci. 
8:73. 1889. 
Perennial by long creeping or horizontal root- 
stocks, glabrous or strigose-pubescent; stem erect or 
assurgent, commonly simple, channeled, enlarged 
at the nodes, 1°-3° high. Leaves ovate-lanceolate 
or oblong-lanceolate, or the upper sometimes nar- 
rowly lanceolate, 2%’-8’ long, acute or usually acu- 
minate at the apex, rounded or cordate at the base, 
petioled, the lateral nerves prominent, sometimes 
forking; ocreae cylindric, becoming loose, not cili- 
ate; racemes I or 2, erect, 1/-3/ long, linear-oblong, 
dense, calyx dark rose-color, 5-parted; stamens 5, 
exserted; style 2-cleft, exserted; achene broadly 
obovate or orbicular, 1%/’ long, very convex, 
lenticular, black and slightly granular, but shining. 
In swamps and moist soil, Ontario to Northwest Ter- 
ritory and British Columbia, south to V irginia, Louisi- 
ana and Mexico. Ascends to 3000 ft. in Virginia. 
July-Sept. 
5: Polygonum Portoricénse Bertero. Dense-flowered Persicaria. (Fig. 1322.) 
Polygonum densiflorum Meisn, in Mart. Fl. Bras. 5: 
Part I, 13. 1855. Not Blume, 1825-26. 
Polygonum Portoricense Bertero; Meisn. in DC. Prodr. 
14: 121. 1856. 
Perennial, more or less scurfy; stem erect, decum- 
bent or floating, 3°-5° long or longer, branched, en- 
larged at the nodes, often dark brown. Leaves lan- 
ceolate or linear-lanceolate, 1!4’-12’ long, acuminate 
at both ends, obscurely punctate, short-petioled, the 
nerves prominent beneath; ocreae cylindric, some- 
times bristly when young, naked when mature, some- 
times hispid; racemes spicate, paniculate, often in 
pairs, 1/-5’ long, dense, erect; calyx white or whitish, 
5-parted to near the base; stamens 6-8, included; style 
2-3-cleft, somewhat exserted; achene lenticular and 
strongly biconvex or 3-angled, 1’’-14’’ long, broadly 
oblong, orbicnlar or even broader than high, black, 
smooth and shining, or minutely granular. 
In wet soil, Missouri to Florida, Texas, the West Indies 
and South America. May-Nov. 
