14 
AMERICAN JOURNAL OF BOTANY 
[Vol. 9 
once manifests itself. Taxodium and Nyssa become scarcer, and a mixed 
stand appears of Acer rubrum var. Drummondii (H. & A.) T. & G., Planera 
aquatica (Walt.) J. F. Gmel., Populus deltoides Marsh., P. heterophylla L., 
Carya aquatica (Michx. f.) Nutt., Fraxinus profunda Bush., Styrax americana 
Lam., and Gleditsia aquatica Marsh.; the latter sometimes forms pure, 
impenetrable stands. Frequently there occur here treeless areas which 
are usually covered with Juncus acuminatus Michx., /. scirpoides Lam., 
Eleocharis acuminata (Muhl.) Nees, E. intermedia (Muhl.) Schultes, E. 
palustris (L.) R. & S., Cyperus flavescens L., and C. acuminatus Torr. & 
Hook., besides most species which are also to be found along the treeless 
margins of the lake. In some old mud ponds where a part of the year 
water has been left, characteristic groups of Salix nigra Marsh, and 5. 
longifolia Muhl. cover large stretches. 
Fig. 3. A mixed forest. A, Leitneria floridana. B, Taxodium distichum. C, Salix 
nigra. D, mixed growth of Platanus occidentalis, Morus rubra, Celtis occidentalis, Quercus 
sp., Ulmus americana, etc. E, Cephalanthus occidentahs, Sambucus canadensis. F, swamp 
with Scirpus lacustris. 
On the higher elevations of the bottom lands which are not as often 
subject to overflow, with the exception of high floods caused by such streams 
as the Black River and the St. Francois River, dense forests are to be found of 
a very diversified tree growth. On account of the richness of the soil the 
trees attain considerable height and thickness, one of the largest being 
Platanus occidentalis L., which is followed in size by beautiful individuals of 
Quercus alba L., Q. rubra L., Q. macrocarpa Michx., Q. bicolor Willd., Q. 
Michauxii Nutt., Ulmus fulva Michx., U. americana L., Tilia americana L., 
Juglaris nigra L., J. cinerea L., Sassafras officinale Nees & Eberm., as well 
as of Quercus phellos L., Morus rubra L., Celtis occidentalis L., C. mississippi- 
ensis Bosc, Liquidambar Styraciflua L., Acer rubfum (H. & A.) T. & G., 
Fraxinus americana L., Carya alba (L.) Koch, C. illinoensis (Wang.) K. 
Koch, Pyrus coronaria L., Aesculus Pavia L., Gymnocladus canadensis 
Lam., Cercis canadensis L., Magnolia tripetala L., Liriodendron Tulipifera L., 
Cladrastis lutea (Michx. f.) Koch, Crataegus sp., Populus heterophylla 
Marsh., and P. deltoides Marsh. All these species grow near one another, 
not one forming a pure stand with the exception of Asimina triloba Dunal, 
which often covers whole thickets several acres in extent. On such lands 
Taxodium and Nyssa are very rare. 
