LEGUMES 



LESPEDEZA 



395 



biosis, a living together. The term is now gener- 

 ally applied to those cases of symbiosis where there 

 is a mutual benefit to the symbionts. This special 

 kind of symbiosis is often called mutualistic or 

 reciprocal symbiosis to distinguish it from those 

 cases of symbiosis existing between a strict para- 

 site and its host, which is called antagonistic sym- 

 biosis. 'Disjunctive symbiosis has reference to the 

 relation of flowers and insects in pollination, while 

 contact symbiosis has reference to the relation 

 between the bacterium, Glostrydium pasteurianum, 

 and certain low, blue-green algae in the soil, the 

 algse supplying the bacterium with carbohydrates. 

 These carbohydrates supply the Glostrydium with 

 the energy which enables it to assimilate free 

 nitrogen. 



Some have raised an objection against the use of 

 the term symbiosis applied to the relation of the 

 nodule bacterium and the legume, on the ground 

 that the bacterium is a parasite, that certain cells 

 in the tubercle are destroyed, and that it is difiicult 

 to see what benefit the host can derive from an 

 association with a parasite which destroys some of 

 its cells. It is beyond contradiction, however, that 

 leguminous plants do benefit from this association, 

 in the fixed nitrogen which they are able to absorb 

 from the dead bacteroids in the nodule, except 

 perhaps in soils already rich in nitrogenous plant- 

 food, under which condition it is known that few 

 nodules are formed, while in soils poor in nitroge- 

 nous plant-foods many nodules are formed and the 

 legume profits to a great extent from the symbiosis. 

 The parasitism is confined to the nodular roots or 

 mycorhiza. This nodule serves a useful purpose for 

 the legume, and the fact that its formation is 

 caused by a parasite, and that some of its cells die, 

 does not necessarily lead to the conclusion that the 

 legume does not benefit by the association. Other 

 normal organs of the plant, as leaves, perform 

 special and important work for the plant, and later 

 die. But the good they have served the plant more 

 than balances the loss of the part or the death of 

 its cells. 



It has also been recently stated that since the 

 early relation of the bacterium in the nodule is 

 that of a parasite, this relation cannot be symbiosis 

 in the sense in which DeBary used the term. Now, 

 DeBary distinctly says in his "Die Erscheinung der 

 Symbiose," 1879 (the following is a translation), 

 "The best known and most exquisite phenomenon 

 of symbiosis is complete parasitism, i. e., that 

 arrangement by which an animal or plant goes 

 through its entire vegetative process on or in 

 another organism belonging to a different species. 

 The latter serves the parasite exclusively as a 

 dwelling place and furnishes it with its entire food 

 material ; it is in every sense of the word its host." 



Literature. 



H. Marshall Ward, some recent publications 

 bearing on the question of the souices of nitrogen 

 in plants. Annals of Botany, 1, 325-357 (1888); 

 Atkinson, The Biology of the Organism Causing 

 Leguminous Tubercles, Botanical Gazette, 18, 157- 

 266, plates 12-15 (1893); Moore, Soil Inoculations 



for Legumes, Bulletin No. 71, Bureau of Plant In- 

 dustry, United States Department of Agriculture 

 (1905); Pfeifer, Physiology of Plants, 1, 393-^03 

 (1900). The literature referred to in these works 

 will supply other references. Germ life in the soil 

 is discussed at length in Vol. I, Chapter XIII, of 

 this Cyclopedia, and should be read in this connec- 

 tion. Additional references to literature are given 

 there. 



LESPEDEZA. Lespedeza striata, Hook and Arn. 

 Leguminosm. (Japan clover, Japanese clover. 

 King-grass, Hoopcoop.) Pigs. 593, 594. 



By Samuel M. Bain. 



An annual forage plant with stems diffusely 

 branched, decumbent, or erect when crowded, three 

 inches to two feet or more in height, subpubescent; 

 leaves three-foliolate, leafiets oblong-obovate, peti- 

 oles very short ; peduncles very short, one- to five- 



Fig. 593. Japan clover {Lespedeza striata). 



flowered; flowers appearing singly in axils of leaves; 

 corolla purple ; pod small, little exceeding the 

 calyx. In the vegetative state the plant is easily 

 confused with Trifolium proeumbens (low hop- 

 clover). They may be readily distinguished when 

 in flower, however, as the latter produces much 

 smaller yellow flowers in true heads. 



Distribution. 



Lespedeza, or Japan clover, as it is more com- 

 monly known, is supposed to have been introduced 

 accidentally into South Carolina, where it was first 



