OUR AMPHIBIOUS PERSICARIAS 2a8 
Good examples of the aquatic phases are my numbers 917A, 
gi7ab, 916a and g16ab, 917aab. Numbers 917abb and 917b are 
good riparian specimens, and 917c, 917ced, 917d, 917de, 916¢e, 
gi6ee, 917ee show all the intermediate transitional phases from 
the first, which is strictly aquatic, to the last which is strictly 
terrestrial, having lost all trace of borders to the ochreae. No. 
917d had leaves 20 cm. long and less than 5 cm. wide. Nearly 
all the aquatics show traces of the beginning of terrestrial foliage. 
All were collected June 22, 1911 around and in a small pond about 
a mile in circumference west of Studebaker’s Woods,* and south 
of South Bend, Indiana. 
No. 917ee may be chosen as type of the sterile terrestrial phase. 
It begins already to lose the borders of the ochreae. No. 917a 
may be considered as a good typical spring aquatic. No. 941¥v 
represents the summer and fall aquatic as also 941x. Both were 
collected July 13, 1911 at the same place. No. 941bed, gathered 
at the same place, on the same day, shows the characteristic fall 
sterile plant. 
As the type of the flowering plant No. 941bcde is the 
best example and this is in fact the type of the species. The 
specimen was collected July 12, 1911 at the above mentioned 
locality. No. 941b is a unique example only one of which I have 
been able to find’ during several years that I have frequented 
the place, of a riparian blooming plant. The lower foliage is 
typically aquatic with three glabrous long petioled leaves; the 
upper foliage is typically terrestrial. No. 1806 shows the fruiting 
plant gathered Sept. 19, 1911, at the same place. 
This plant is readily distinguished from P. mesochora, its 
nearest ally on the one side, by the fact that it never blooms in 
the floating aquatic phase, as also by the characteristic habit an 
pubescence. It is intermediate between P. mesochora and P. 
tanaophylla, and distinguished from the Jatter in the presence of 
borders to the ochreae as well as the pubescence and shape of 
foliage. The latter also blooms at least occasionally in an aquatic 
condition. As far as habit is concerned, the plant connects the 
members of the Hartwrighttanae as a group to which it strictly 
belongs, by means of P. tanaophylla to the Emersae group. Any 
one not knowing its spring phases would unhesitatingly class 
P. caractorum as anear ally of P. coccinea and P. pratincola, or more 
likely near P. vestita which in bloom it somewhat resembles, but 
