LANDMARKS OF BOTANICAL HISTORY GREENE 257 



exclusively to these plants, and a considerable number of them of 

 various genera, embracing an aggregate of some thirty species. The 

 next chapter treats of mosses ; the third, of mistletoe. Thus the 

 whole assemblage of German saprophjrtes and tree parasites is made 

 one ecologic group, as of things growing together, many of them 

 upon trees, most of the others upon the ground beneath trees. 



Ecology, however, forms an item and a very distinct one in the 

 account of almost every wild plant which he describes ; a fact that 

 will be best impressed by a few citations. 



"Asarum affects shady places where the soil is rather moist, 

 and is usually found under thickets of hazel, but sometimes also 

 in deep damp woods. "' 



" AUiaria is an elegant plant which in the month of April is found 

 in certain waste places, under walls, along the bases of hills, by 

 hedges and in cavernous places which are the abode of lizards and 

 other vermin. "^ The chickweed is located thus: "This most com- 

 mon of herbs is found throughout the whole year in gardens and 

 vineyards; and the richer the soil, the more large and tender the 

 herbage."^ 



Ranunculus sceleratus "grows in low swamps, especially if the 

 soil be sandy, and preferably where there are frogs; but occasionally 

 in very rainy years it will be found in wet lands that are more ele- 

 vated. "4 



"Fumaria grows in gardens, fields of rye, and also among flax, 

 onions, and cabbages, where it flowers in May, and again in autumn 

 it reappears in turnip fields. "^ 



The almost omnipresent knotgrass, Polygonum aviculare, he 

 thus descants upon: "Polygonum among common plants is the 

 very commonest of all, at the same time a useful one also. What 

 part of the country is there where one does not meet with it ? What 

 roadside is there where it does not abound? What fields (for in 

 cultivated fields it particularly delights) , what hedgerows, and what 

 by paths are not covered with it? "* 



"Aquilegia, mostly a garden plant with us, also grows wild in 

 elevated woodlands, on rocky hills, and sometimes in the crevices 

 of precipitous rocks. " ' 



' Stirp. Comm., p. 65. 



» Ibid., p. 85. 



» Ibid., p. 384. 



* Ibid., p. 93, under the name Apium aquaticum. 



s Ibid., p. III. 



« Ibid., p. 390. 



1 Ibid., p. 136. 



