KARE NATIVE PLANTS FERNALD 379 



obliterated by the crowding and handsome but overwhelming flower- 

 ing rush {Butomus unibellatus) and the purple loosestrife {Lythrwm 

 Salicana) ^ both gorgeous to look upon but unscrupulous and without 

 mercy for the insignificant endemics, which cannot last many years 

 longer. Similarly, on the lower Merrimac the same purple loose- 

 strife, a joy to the artistic and unscientific eye, has obliterated the 

 fastidious and localized endemics, which had become isolated there 

 since the last withdrawal of the Champlain sea. 



Unfortunately, these vagrant, aggressive, and opportunist weeds 

 from Europe are destined to be the cosmopolitan flora of temperate 

 regions as soon as man has a little further interfered with the natural 

 habitats of our long-established native floras. They are our thor- 

 oughly successful wild plants, and their success is to be compared 

 with that of the European man, the European rat, the European 

 mouse, the European house (or "English") sparrow, the European 

 starling, the European gypsy moth, the European brown-tail moth, 

 the European house fly, and other invaders which, wherever they can 

 get an opening, are rapidly replacing our indigenous Indians, rodents, 

 birds, and insects which had long ago established an equilibrium. 



In our native flora, likewise, there is a group of aggressive invaders, 

 certain plastic and pioneering species which, along with the vagrants 

 of European origin, often take possession of newly cleared and dis- 

 turbed land: Pasture brake, flyaway grass {Agrostis scabra), aspen 

 (Populiis tremuloides) , gray birch {Betula popuUfolia), hardback 

 (Spiraea to?nentosa), wild strawberry, raspberry, blackberries, bird 

 cherry, yellow ladies'-sorrel {Oi'olis europaea)^ poison ivy, fireweed, 

 pennyroyal, horseweed, and a hundred more. These are our native 

 invaders but they are relatively harmless. They have been longer on 

 the ground and, although showing some of the unrepressed traits of 

 aggressive youth, they are surely less obnoxious in their behavior than 

 are many of the recently arrived European invaders. 



Then there are the dominant but unaggressive species, abundant 

 over vast areas but show^ing little or no tendency to push in where 

 they are not wanted: Cinnamon fern, various club mosses, ground 

 yew, Indian poke, bayberry, hazel, beech, common clematis, colum- 

 bine, sugar maple, and hundreds of others. These are the common 

 species of appropriate wild habitats, the backbone of our flora, the 

 bourgeois, vigorous, fertile, dependable, chiefly of late Tertiarj^ dis- 

 persal and eminently respectable. 



After them I should place the quiescent species, locally abundant 

 over large areas, absent from equally extensive areas: Maidenhair 

 fern, adder's-tongue fern, shagbark hickory, marsh marigold, blood- 

 root, climbing bittersweet, wicopy or leatherwood, ginseng, bottle 

 gentians, fringed gentian, and three or four hundred others. These 



