380 THE AMERICAN NATURALIST. [VoL. XXXIV. 
Locality I. — A small clump of perhaps fifteen plants, grow- 
ing in the edge of a little creek that was formed by the conflu- 
ence of a number of ravines, near the lake and almost at the 
lake level. But one clump was found in this situation, and it 
bore but fourteen flowering stems; but, because of its striking 
vigor, fertility, and comparative exemption from insect ene- 
mies, it is included in the table. 
Locality 2. — A large area of flags, growing in an upland 
meadow pool that was the head water of one branch of the 
forementioned creek. This was the most extensive and the 
most typical of the clumps studied. 
Locality 3. — A large and compact clump, growing in the 
edge of a woodland pool. 
Locality 4. — Isolated single plants, growing between the 
sedges and the open water in a woodland pool. 
Locality 5. — A large number of scattered plants, growing 
among the sedges of a **filled-in"" pool. 
Locality 6. — A typical glacial “ pothole " in deep woods on 
the summit of the moraine, with abrupt banks, some depth of 
water in the middle, closely bordered with great oaks, and 
almost filled with a dense growth of buttonbush (Cephalan- 
thus) The flags grew between the buttonbush hummocks and 
the shore, tall and spindling, with remarkably pale flowers. 
They bloomed late, the water of the pothole being rather cold, 
and, with the exception of two flowering stems which grew 
upon an unoccupied hummock, set no seed at all; hence this 
locality is omitted from Table II. 
Locality 7. — At the foot of a hill bordering the creek men- 
tioned above (locality 1), in a pool of cold water, the outflow 
from a spring, grew perhaps fifty plants, intermixed with cat- 
tails and sedges. These made a very promising appearance, 
but they bloomed late; the flowers were considerably damaged 
by weevils and set little seed, and that little was early destroyed 
and none left for tabulation. 
Locality 8. — In a bottom-land pasture bordecide the creek 
numerous large, apparently healthy, clumps on dry ground. 
This ground had once been marshy bottom land; but as a result 
of pasturage, tillage, and deforestation of the hills above floods 
