(5) Epilohium molle Torr., willow-herb, 

 (i*) Myriophyllum spicatum L., water milfoil, 

 (i*) " heterophyllum Michx., water milfoil. 



(3) Proserpinaca palustris L., mermaid- weed. 



(3) Hippuris vulgaris L., mare's tail. 

 (3, 5) Slum cicutaefolium Schrank., water parsnip. 

 (3, 5) Cicuta hulhijera L., bulb-bearing water hemlock. 



(5) " maculata L., water hemlock. 



(5) Lysimachia thyrsiflora L., tufted loosestrife. 



(5) " terrestris BSP., bulbous loosestrife. 



(3) Menyanthes trifoliata L., buckbean. 



(5) Asclepias incarnata L., swamp milkweed. 



(5) Verbena hastata L., blue vervain. 



(5) Scutellaria galericulata L., marsh skullcap. 



(5) Lycopus americanus Muhl., water horehound. 



(5) " virginicus L., bugle weed. 



(5) Mentha arvensis canadensis L., Canada mint. 



(3) Veronica Anagallis-aquatica L., water speedwell, 

 (i*) Utricularia vulgaris L., bladderwort. 



(i) " minor L., smaller bladderwort. 



(i) Dianthera americana L., water willow. 



(3) Plantago cordata Lam., river plantain. 



(5) Galium asprellum Michx., marsh bedstraw. 

 (3» 5) Campanula aparinoides Pursh., marsh bellflower. 



(5) Eupatorium purpureum L., Joe-Pye weed. 



(5) " perfoliatum L., boneset or thoroughwort. 



(5) Solidago graminifolia Salisb., grass-leaved goldenrod. 



(5) Cirsium muticum Michx., swamp thistle. 



(5) Bidens trichosperma Britton, marsh stick-tight. 



(5) " frondosa L., beggar-tick. 



IV. THE PEAT BOG ASSOCIATIONS 



The associations in the peat bog series that are best developed are 

 (i) the sedge, (2) the xerophytic shrub, (3) the tamarack, and (4) the 

 pine-birch forest associations. No separate discussion of the stages in 

 the succession will be attempted but the association in which the follow- 

 ing species occur most abundantly will be indicated. These associations 

 are seen at Mineral Springs and Mill Creek, Ind., and Fox Lake, 111. 



Trees and Shrubs 



(4*) Pinus Strohus L., white pine. 



(4) Thuja occidentalis L., arbor vitae. 



(3*) Larix laricina Koch., tamarack or American larch. 



(1,2) Salix pedicellaris Pursh. 

 (i, 2) " Candida Flugge, hoary willow. 

 (2) " discolor Muhl., glaucous willow. 



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