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SCIENCE. 



[X. S. Vol. XVIU. No. 450. 



the pine woods. This, as Mr. Livingston 

 justly remarks, has disappeared in most places 

 and has been supplanted by the flora of the 

 lighter, drier oak openings. Only remnants 

 of the true coniferous flora still remain, but 

 Epigcea repens, GauUheria procumbens, Myr- 

 ica asplenifolia and the upland huckleberries 

 and blueberries are still of occasional, or in- 

 deed locally of frequent, occurrence. 



Of strictly mesophytic forest types we have 

 then three, that of the beech and maple tim- 

 berlands, that of the oak openings, and that 

 of the pine woods. Of these the last is dis- 

 appearing, and its remnants have, save in a 

 few tracts of still standing pine, coalesced with 

 the flora of the oak openings. In addition to 

 the above, small tracts of almost pure birch 

 are occasional, and in forests that have suf- 

 fered most from fires a salicaceous type is 

 often developed, consisting of various willows 

 and our two aspen-poplars. Hawthorn glades, 

 too, are of frequent occurrence, consisting 

 mainly of species of Gratcegus, Pyrus coro- 

 naria and various other shrubs. 



Turning our attention now to details, we 

 may well distrust the value of using common 

 weeds, such as catnip, pokeweed, nightshade, 

 spurges and even sand-burs as typical plants 

 of native sylvan societies. These are plants 

 capable of wide range of soils and conditions. 

 They were not weeds else. Doubtless our 

 common stick-tight (Bidens frondosa) is a 

 hydrophyte, yet hardly is there any field where 

 it is not too common. The sand-bur with 

 us is a straggler from the sands of the Great 

 Lakes, and is hardly indigenous except along 

 our rivers. Now it is along all paths, road- 

 sides and railroads. The common nightshade 

 is a cosmopolite, and frequent everywhere. 



As to the spurge, which is narrow-leaved or 

 wide-leaved according to the society in which 

 it grows, probably Euphorbia corollaia is 

 meant. I think that the width of the leaves 

 varies with the age of the plants. In early 

 summer, before the plant has branched, the 

 cauline leaves are broad, but the later leaves, 

 especially those on the branches, are much 

 narrower. Nevertheless, the soil has also an 

 influence, on the robustness of this spurge, as 

 it has on most species. 



Dracocephalum parviflorum is given in the 

 table as a frequent and characteristic plant of 

 the beech-maple society. This plant I have 

 never seen, and in the ' Flora of Michigan ' 

 published in the report of the Michigan Board 

 of Agriculture for 1891, but three stations 

 are given of this rare plant in the Lower 

 Peninsula — Houghton Lake, Alcona County 

 and Hubbardston. Perhaps it is locally 

 abundant in portions of Kent County, and 

 Mr. Livingston will oblige all students of the 

 Michigan flora, if he will name exact localities. 



Quercus ilicifolia similarly is given in the 

 list as a frequent and characteristic plant of 

 the oak-pine-sassafras society. It has not, to 

 my knowledge, ever been reported before from 

 any place in Michigan. According to all the 

 manuals this oak is restricted to the Atlantic 

 and Appalachian regions, not occurring west 

 of portions of Ohio. It is hard to determine 

 what oak has been confused with this strictly 

 eastern species. The shingle oak, Quercus 

 imbricaria, I have not seen north of the lower 

 tier of counties in Michigan, though it is said 

 to grow at Ann Arbor. The black jack, Quer- 

 cus marilandica, is not known to occur cer- 

 tainly in Michigan, though it is mentioned in 

 old lists as occurring in the extreme south. 

 The species intended by Quercus ilicifolia is 

 doubtless Quercus coccinea, or its variety 

 tinctoria, in some of its scraggly dwarf forms. 



The term Quercus rubra coccinea is neither 

 exact nor scientiflc, as the two species are 

 very easily separated by the mature fruit as 

 well as by the buds. Only by those who 

 judge the trees by the foliage at a distance 

 are the two likely to be confused. Though 

 they occasionally grow together, the red oak 

 is oftener found at the margins of swamps 

 and more rarely in the lighter soils. It, too, 

 is occasional in the timberland forests. If 

 the oak forest is to be divided as sharply as 

 Mr. Livingston has divided it, the two must 

 be separated. 



The herbs given by Mr. Livingston as 

 characteristic of the several plant socifeties 

 are nearly all of the midsummer vegetation; 

 his studies of the region quite likely took 

 place then. Perhaps even better types could 

 be chosen from the vernal species. Then, too. 



