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258 MISSOURI BOTANICAL GARDEN. 



EXPLANATION OF PLATES. 



Plate 10.~The Missouri shore at Selma, 42 miles south of St. Louis, 

 showing the oak-covered plateau, the bare upper portion of the limestone 

 cliffs and the vegetation-covered talus at the base, the railroad embank- 

 ment and the shelving beach of the Mississippi, 



Plate 11. — The Mississippi River at Selma, showuig islands with their 

 adjacent mudbanks. In the distance lie the wide and level stretches of 

 the American Bottom. 



Plate 12. — 1, Upland pond near the edge of the bluff in the woods south 

 of the buildings at Jefferson Barracks. 2, Projecting limestone ledge of 

 .the bluff south of Jefferson Barracks, The tree is Fraxinus viridis. 

 Stems of Tecoma radicans run over the stone. Two plants of Solldago 

 Drnmmondii and one of Pellaea atropurpurea have established themselves 

 in crc\ices. 



Plate 13. — Sinkhole vegetation, in this case consisting mainly of 

 Hydrastis canadensis, which is In fruit. In the lower right hand corner 

 can be seen leaves of Arisacrna triphyllum and in the center a plant of 

 Arisaema Dracontium, To the right of this are two plants of Smilacina 

 racemosa and in the upper right hand corner two plants of Podophyllum 

 peJtatum. 



. Plate 14.— 1, Upland swamp in the woods south of the buildings at 

 Jefferson Barracks. The wide flat is covered with willows. Along the 

 edges other plants appear, especially Iris versicolor and ferns. 2, Convol- 

 vulus Sepium twining among willows in the "bottoms" on the Missouri 

 side of the Mississippi. 



Plate 15. — 1, " Bluff quarry" along the Mississippi river bluffs south of 

 Jefferson Barracks, showing the projecting limestone ledges along the 

 railroad track. On the left may be seen the thick covering of loess, 



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deposited on the limestone during the Quaternary period. 2, Mouth of a 

 creek south of Jefferson Barracks^ showing the aliuost horizontal strati- 

 fication of the St. Louis limestone at this point and the erosion due to the 

 continued action of a comparatively small amount of water. 



Plate 16. — Partially cut and burned vegetation on the railroad embank- 

 ment near Jefferson Barracks, the growth consisting chiefly of Rhus glabra, 



Plate 17. — Polygonum Hartwrightii in the wet bottoms of the Mississippi 

 river near Jefferson Barracks. 



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Plate 18. — River des Peres and the adjoining bottoms east of the 

 Broadway bridge. On the right is seen a dense growth of willows; in the 

 center, clumps of Forestiera acuminata. In the distance, at the left, is a 

 bank covered with oaks. 



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Plate 19.— Detail of the preceding plate. 1, Clump of Forestiera acumi- 

 ' nata; at the left a single tree of Gleditschia triacanihos. 2, On the right, 

 willows; on the left, Ulmus americana; plants of Vernonia noveboraccnsis 

 and of Forestiera acuminata in the foreground. 



Plate 20. — Nelumhium lutcum and Polygonum Muhlenhergii in Pitts- 

 burg Lake, St. Clair Co., 111. The dead and dying trees are willows. 



