196 The Ohio Naturalist. [Vol. XI, No. 1, 



are rapidly disappearing as the clearing of the area nears comple- 

 tion. The indications are that in a few years the last vestige of 

 this interesting aggregation of plants will be destroyed. 



This type of bog is distinctly northern in its distribution and 

 has not been observed by previous writers to occur south of the 

 central part of Michigan. The brief time which could be given 

 to the locality made a more detailed study and the mapping of the 

 area impracticable. Yet the notes and records, made have 

 ' revealed a considerable number of species hitherto supposed to be 

 confined to the states north of Ohio. 



In several places the groves of arbor vitae are dense pure 

 stands or facies with scarcely any undergrowth. The association 

 has only a single vertical layer in which the lowermost branches of 

 the component inchviduals bear a common spacial relation to 

 light. The ground is littered with cedar foliage and only occasion- 

 ally small sprouts of the chokeberry (Aronia arbutifolia), and 

 stunted seedlings of yellow poplar ( Liriodendrcn tulipifera) or 

 small plants of the spice bush (Benzoin aestivale), alders, and 

 woodbine are visible; generally there are no members of a subor- 

 dinate species other than a few mosses and liverworts. In more 

 open stands in which the effects of fire and cuttings are still 

 present the arbor vitae is found here in association with the red 

 maple (Acer rubrum), yellow poplar, (Liriodendrcn tulipifera), 

 black ash (Fraxinus nigra), white walnut (Juglans cinerea), 

 Sycamore (Platanus occidentalis), and wild cherry (Prunus 

 serotina). The undergrowth is not only numerous in species but 

 of exceptional height and in five layers. The poison sumach 

 (Rhus Vernix) reaches freciuently a height of twenty-five feet. 

 Other members of this structural part of the formation, and 

 determining more specifically the physiognomy of the layer, are 

 the alders (Alnus incana, A. rugosa), the winter-berry (Ilex 

 verticillata), the chokeberry (Aronia arbutifolia), and the round 

 leafed dogwood (Cornus circinata). The inferior layers which 

 seem to be entirely determined by the density of the mixture of 

 facies are really overlapping communities of woodland and bog 

 plants. There seems scarcely no relation to habitat factors. 

 Seedlings and s]3routs occur in all directions, in various degrees 

 of abundance, and only the less hardy plants lose ground, thus 

 producing examples of an indiscriminate alternation. The spice 

 bush (Benzoin aestivale) is only of relatively less importance in 

 the (second) stratum of bushes to the red bud (Cercis canadensis) 

 and the elderberry (Sambucus canadensis). 



The subordinate position with regard to the taller species is 

 occupied by the cinnamon fern (Osmunda cinnamomea), the 

 meadow rue (Thalictrum dasycarpum), the spikenard (Aralia 

 racemosa), the bladder fern (Cystopteris bulbifera), and touch-me- 

 not (Imi)atiens sp.). With them in varying abundance occur 



