54 MISSOURI BOTANICAL GARDEN. 
Farther eastasmall stream enters the lake and along its quiet 
shore Jussiaea repens formsaconspicuous border, (Plate 9.) 
Scirpus maritimus is wanting and Polygonum Muhlen- 
bergii and Sium cicutaefolium crowd each other for the 
next place and then quickly give way to a shrubby thicket 
of Salix nigra, S. amygdaloides and S. longifolia, which, 
in turn, are almost entirely succeeded by Forestiera acu- 
minata, a form which seems so well adapted to this habitat, 
that other forms scarcely exist in the almost impenetrable 
thicket it makes beyond the willows. There is no ground 
vegetation whatever and only an occasional willow. An 
interesting adaptation is shown by the Forestiera which 
accounts in part for this dense thicket growth. Where 
the long, drooping branches touch the wet soil, roots are 
quickly put out and in a short time young and independent 
trees have originated. (Plate 10.) Somewhat north of 
this thicket an axe clearing has been made, and here the 
same willows are beginning to come in. 
Typha latifolia is the commonest plant here, Bidens 
frondosa nearly equaling it. Sagittaria variabilis occupies 
the moister places, Penthorum sedoides is also frequent 
and seedlings of Acer dasycarpum are abundant. Bound- 
ing the Forestiera thicket and the clearing one finds large 
trees of Fraxinus Americana and Acer dasycarpum farther 
back. 
6. A CYPRESS-TUPELO GUM SWAMP ALONG THE ST, FRANCIS RIVER. 
A tract of land lying in Dunklin County, Missouri, and 
in Greene County, Arkansas, furnishes an excellent area 
for the study of a semi-southern river swamp. Through 
this territory runs the Saint Francis River, and it, together 
with its tributaries, covers wide stretches of the lowlands 
with a varying depth of water. At some seasons one may 
pass dry-shod over miles of woodland, which at other 
Seasons is covered with water to a depth of two feet or 
more. It is this variability in amount of water which ren- 
