THE AMERICAN BOTANIST 31 



such as Dessert and LeMoine, the latter's splendid novelties in 

 lilacs, philadelphus, deutzias, etc., must keep away from these 

 shores. Blackmore and Langdon's fine begonias, Wallace's 

 world renowned irises, the fine collection of British montbre- 

 tias, Dickson's fine roses and the wonderful things of other 

 British producers will not be tolerated here any longer. We 

 must call back our own Wilson, he who collected so many 

 valuable plants, roots and bulbs which draw thousands to the 

 Arnold Arboretum — call him back from his present exploring 

 tour of the interior of China and Japan with the statement 

 that America does not want any of his plants." One can but 

 wonder what Old World horticulture would have looked like, 

 had England France and Belgium had a Federal Horticultural 

 Board like ours. 



Dwarf Shore Floras. — The plants of any region, as 

 all ecologists know, are assembled in groups or associations, 

 according to the character of the soil and the amount of water 

 at their disposal, but in regions where there is a sharp transi- 

 tion from wet to dry, as on river and lake shores, the plants 

 often have to make very rapid adjustments to the environ- 

 ment, which results in a great change in form. It is among 

 shore plants that we most frequently find species with varying 

 forms of leaves. Often there are three kinds : dissected water 

 leaves, broad floating leaves and firm aerial ones. Illustra- 

 tions will come to mind in such species as the water parsnip, 

 water star-grass {HeterantJiera,) water plantain, water crow- 

 foot and various species of potarnogeton and polygonum. A 

 second feature of the shore flora is the dwarfing effect the 

 situation has on plants from other regions that stray into it. 

 Owing to the height of the water, probably, the lower shores 

 are not suitable for growth until late in the season, so that 

 such plants as grow there have to develop very quickly. This 

 calls for a great reduction in vegetable structures. H. W. 

 Clarke, who has investigated the matter, reports finding eight- 



