238 AMERICAN MIDLAND NATURALIST 
sufficient to convince one more than anything else of the futility 
of studying, amphibious smartweeds from isolated plants or phases 
of such as have hitherto found their way into our herbaria. 
Another almost similar series of the same phases of the same 
plant, I collected about eight miles southesat of South Bend, 
Ind., on the border of a tamarack swamp along the Turkey Creek 
Road, two miles west of Woodland. The plants number 915m to 
g15u were collected in a pasture along what was to all appearance 
the edge of the water before the large drainage ditch was dug 
that is rapidly destroying the largest tamarack swamp in St. 
Joseph County. Though not standing in water the lower leaves 
are glabrous, and resemble those of the intermediate transition 
phase of the preceding series up to the normal terrestrial. Doubt- 
less later the plants become normal terrestrials, but when appear- 
ing early in the season, they have not as yet, though now high and 
dry, lost their tendency to grow their first foliage as subaquatic 
in appearance. The later growth of older plants is already dis- 
tinctly terrestrial, though at first subaquatic in character, thus 
hinting at their previous history of submersion not many years 
ago. In other words the species P. ammophila survives because 
of its ability to change rapidly, even in one season, from aquatic 
sterile phase to the terrestrial. 
Strictly normal aquatic phases, flowering with none, but 
floating glabrous foliage, I have not been able to find in spite 
of long and repeated search at various seasons of the year from 
the very first days of flowering until the spikes ran to seed late 
in fall. In one particular locality, at Millers, Ind., the plant is 
most abundant, and I have come to the conclusion that the plant 
has no strictly flowering aquatic phase, thus emphasizing beyond 
any doubt the utter impossibility, for the present at least, if my 
investigations are sufficient, of connecting P. ammophila Greene 
with such plants as P. canadensis Greene or P. fluitans Eaton, 
whose aquatic foliage resembles that of P. ammophila, but which 
flower only in the aquatic phase. If the specimens I found at 
Millers, flowered as normal aquatics we might infer that P. am- 
mophila was but the terrestrial phase of P. canadensis or P. 
fluitans. But the first has never been known to bloom until the 
aquatic foliage was replaced by terrestrial at least in part, and the 
last two have not as yet been found with any terrestrial phase. 
It may even be likely from their deep water habit that they have 
