a" 
OUR AMPHIBIOUS PERSICARIAS 229 
P. ammophila, everywhere so abundant there, but no collections 
of such specimens were made at the time and the identity of the 
plants can not be positively proved. Moreover, the locality is 
rich in many amphibious Persicarias, some of which resemble P. 
mesochora, or P. lonchophylla, or even, P. carictorum. 
I may designate as type of the terrestrial phase, which seems 
to be the normal condition of the plant, No. 1901, of my herbarium 
gathered at Millers, Ind., July 9, 1911. Numbers 1901a and rgo1b 
show the long narrow leaves so charactersitic of the species, as 
also the ever-present brownish color of the lower surface of the 
leaves later in the season, that distinguishes it from all other members 
of the emersa group. Other typical specimens are numbers 1903 
collected in another place some distance from the first locality 
and onthe same day. Numbers 2096 and 2099 gathered in the same 
place, Sept. 21, 1911, as also 3002, 3004, and 3005. Numbers 
3002b, 3002¢c and 3004¢ are riparian plants with upper terrestrial 
foliage and the lower leaves about % as long, though of nearly 
the same width, and glabrate, due to previous immersion in shallow 
water. The most striking of these intermediate riparian phases is 
sheet No. 1903a which has lower aquatic leaves much shorter, 
and as broad aquatic ovate oblong to lanceolate, that are quite 
glabrous, with broad base and acute apex, whereas the upper are 
nearly twice as long and acuminate. The petioles gradually shorten 
upwards, and the specimen is as perfect a fertile transition phase 
as I have been able to find. It was collected July 9, rgor. No. 
2465 is the nearset approach to the aquatic phase I was able to 
obtain late in the season. The lower foliage though scabrous 
margined has the long petioles of the water plant though the leaf 
shape is not characteristic. It is more riparian than either strictly 
terrestrial or aquatic. Even riparian blooming plants cf the species 
are rarely to be found. 
SUBAQUATIC PHASE. Plant with small floating leaves ovate 
to elliptic-ovate, acute, subcordate or rounded at the base and not 
over 9 cc. long when on sterile plants, about 2 cm. longer in the 
largest of upper leaves on fertile plants, and 1.5-2.6 cm. wide 
and ovate or ovate-oblong. Petioles 1.5-3 cm. long perfectly 
smooth. The plant blooms rarely in this phase and apparently 
the flowers do not mature seed. The smaller stems rise from a 
long upright one in shallow water and as they rise out of the 
water soon change to terrestrial or riparian. I select as type 
