104 BOTANICAL GAZETTE [ FEBRUARY 
flowering herbs are Trillium recurvatum, Phlox divaricata, Polemo- 
nium reptans, Hydrophyllum Virginicum, Mertensia Virginica, Col- 
linsia verna, Claytonia Virginica, Erythronium albidum, Arisaema 
triphyllum and A. Dracontium, Nepeta Glechoma, Isopyrum biterna- 
tum, Caulophyllum thalictroides, Viola cucullata, Galium Aparine. 
Other characteristic herbs are the nettles (Urtica gracilis, Lapor- 


Fic. 16.—An oxbow lake in the flood plain of Thorn creek. The willows are 
subsequent, dating back to a stream margin, while the shrub (Cephalanthus) and herb 
vegetation is associated with the present undrained condition. 
tea Canadensis), various umbellifers (Heracleum, Cryptotaenia, 
Sanicula, Osmorrhiza), and the parasitic dodder ( Cuscuta Gro- 
novit). fig. 12 shows a characteristic mesophytic flood plain 
forest along the Desplaines river; underneath the elms and bass- 
woods is seen a rich herbaceous flora, consisting largely of Phlox, 
which the picture shows in full bloom. 
In some of the bottom lands there is a rather striking collec- 
tion of trees, whose chief range is mainly southward. Fig. 13 
shows a flood plain tree group near Lockport, most of whose 
members are largely southern, viz., the coffee tree ( Gymnocladus 



