04 NINTH REPORT. 



Jack pine of so large size and abundance as in these barrens. Wherever the 

 sandy ridges spread out into wider expansions, as at Sands for instance, 

 forming broad uplands, now denuded of their original tree growth, and not 

 even subjected to cultivation, a Jack pine and xerophytic flora has established 

 itself with Composita' as its prominent feature. Such plains extend through 

 the metamorphic region to the southern limit of the Upper Peninsula and ap- 

 pear to be indeed the home not only of Jack pine and spruce, but of golden 

 rods, asters, rudbeckias, sweet fern, Pteridium ac|uilinum, Campanula rotiuid- 

 ifolia, Gnaphalium obtusifolium, C'ommandra umbellata, besides numerous 

 other species. 



The pine flora proper is far richer in species, and more interesting. An 

 evergreen arboreal vegetation still forms the most prominent feature of the 

 flora of sand areas and the large number of rocky hills. The societies are 

 dominated by such species as Pinus resinosa, P. strobus, Picea Canadensis, 

 P. mariana, Tsuga Canadensis, Abies balsamea, Juni]:)erus communis antl 

 Taxus Canadensis. The undergrowth is not scanty, although in midsummer 

 only traces of the characteristic spring ])lants are found. The club-mosses 

 flourish here luxuriantly, together with Clintonia borealis, Corallorhiza 

 Corallorhiza, C. multiflora. Linnea Americana, Asplenium filix-foemina, 

 Rubus parviflorus, Phegopteris DryojJteris, Pteridium aciuilinum and others. 

 In more open places ma}^ be seen Gaultheria procumbens, the bear berry, 

 (Arctostaphylos Uva-ursi) Epigsea repens, Chimaphila umbellata, Fragaria 

 Virginiana, Rosa Sayi, with mosses, liverworts, lichens and fungi in great 

 profusion. In young pine woods are always found white birch (Betula 

 papyrifera), and the poplars (Populus tremuloides, P. grandidentata). 

 Balsam, and especially the yellow birch (Betula lutea), are frequent among 

 them. To what extent the original flora is re-established, or has become 

 mixed or displaced the brief period of investigation failed to show. 



Rock Societies. — Originally an unsurpassed tree growth and timber wealth 

 was found here almost uninterrupted. Since no serious obstacles to plant mi- 

 gration from and to all parts are present, it is easily understood why the num- 

 ber of plants endemic to Michigan is small. Completely open on the east and 

 west, naturally the result would be that the plant covering of the state should 

 coincide with the flora of adjoining states. The original arboreal evergreens 

 are now dominated by a society consisting of various maple's, Acer nigrum, 

 A. Pennsyivanicum, A. rubrum, A. saccharum, A. spicatum, red oak, elm, 

 basswood, yellow, black and white birch, white and black ash, wild cherry, 

 ninebark, hop-hornbeam, hazel (Corylus rostrata), and dogwood.^ The 

 beech has not been observed in this locality. It is present, however, south 

 of Marcpiette, and more numerously, I am told, east of the Au Train River. 

 Deciduous trees predominate wherever a richer and deeper soil covers the 

 heights, the slopes of mountains, and the rocky hills. 



The pine is present also, but the changed soil conditions seem to force the 

 pine to give way to the hardwood trees. With the disappearance of the pine, 

 whether through clearing or fire, the deciduous-leaved trees make their ap- 

 pearance, and the undergrowth also becomes more varied. 



Nowhere is there a more excellent field of study illustrating the importance 

 of succession than that presented on the rocks of granite and quartzite in 

 the vicinity of Marquette. The tops of several of these ridges are almost as 

 smooth and barren of vegetation as at the day the glaciers left them. Gravity 

 and rain remove any soil formed to lower levels, and the most favorable con- 

 ditions for plant societies are found, therefore, at the foot of the hill, becoming 

 less favorable higher up the slope. On the rock summits, two conditions 



