16 AMERICAN MIDLAND NATURALIST 
Polygonum amphibium of the American authors either in part 
or by mistake, not of Linnaeus. 
Aquatic Phase. Stems very slender, submerged internodes 
8-15 cm. long, the floating ones 2.5-3 cm. Leafblades perfectly 
glabrous and slimy when young, elliptical to elliptic-oblong usually 
dark red on the lower surface, 3-12 cm. long hardly ever even sub- 
cordate at the base, but tapering abruptly at both ends: spike 
solitary, short. cylindrical, slender peduncled; bracts, broad 
ovate, acute, glabrous: peduncle purple smooth. 
Riparian and Terrestrial phases not known. Found floating 
mostly far away from the shore of sandy bottomed or sometimes 
muddy lakes, usually so far from the shore that any attempt to 
connect it with a land phase seemed hopeless. Though hairy and 
sterile forms with a spreading rim to the ochrea were found in the 
sand some yards from the water line, no connection between them 
could be shown. It was not infrequently found over 100 or even 
130 feet from the water’s edge. Collected at Bankson Lake, San 
José Park, near Lawton, Mich. by myself. It is No. 262 of my 
herbarium. The plant differs from the European P. amphibia 
in that the latter has lanceolate and subcordate leaves with sharply 
scabrous margins. 
The plants were growing with P. grandifolia but usually farther 
out and in a depth of several metres of water. 
PERSICARIA MESOCHORA Greene (1904) Leaflets, Vol. I., p. 28.* 
Polygonum amphibium of American authors in part. Not of 
Linnaeus. 
Aquatic Phase. Plant larger and stouter than P. flwitans: 
petioles as long, but not as slender: leafblades different in shape 
and color, light green with but a slight indication of purple brown 
or red, commonly 12 cm. long, and 3—5 cm. broad, ovate to elliptic 
lanceolate according as the base is broad or subcordate or rounded, 
or somewhat tapering, glabrous and slimy when young sometimes 
minutely puncticulate: spike solitary, rather long stalked, cylindric 
2.5-3.5 c. long: peduncle dark purple glabrous: bracts ovate 
acute glabrous usually partly colored like the flowers. 
Riparian Phase. Stems stouter: internodes 7.5-10 cm. 
long and somewhat fistulous, especially lower down: leafblades 
iy; * This plant is probably the one most commonly taken for P. amphibia 
in our region. 
