80 Effect of Manganese Compounds 



Gossl (1905) gives lists of the distribution of manganese in plants, 

 both Thallophytes and Phanerogams, indicating the presence of much or 

 little of the element. As a rule, he states, marsh and water plants 

 gather up more manganese than do land plants. 



The Gymnosperms seem to be particularly rich in their manganese 

 content. Schroder (1878) tested for the element in firs and pines and 

 found the following amounts of Mn 3 4 . 



In 100 parts ash. In 1000 parts dry matter. 



Fir Pine Fir Pine 



33-18 13-46 2-76 -77 



He gave a table of detailed analyses showing the differing proportions of 

 manganese in the different parts of the fir. 



Baker and Smith (1910) paid special attention to manganese in their 

 exhaustive work on the Pines of Australia. They state that " in the 

 anatomical investigations of the timber, bark, and leaves of the various 

 species, there was found to be present, in a more or less degree, a 

 naturally brownish-bronze coloured substance, which invariably stained 

 dark brown or almost black with haematoxylin." This substance on 

 careful investigation proved to be a compound of manganese. The 

 quantity present varies with the species and also with the plant organs. 

 The different species of the genus Callitris show variable percentages of 

 manganese from a maximum of 0'230 % in G. gracilis, to a minimum of 

 O'OIO / Q in C. robusta. The percentage of manganese in Australian 

 Goniferae other than Callitris is given by the authors in the following 

 table : 



Ash of timber of Agathis robusta 0-145 % Mn. 



Araucaria Cumiinghamii 0'054 % 



Araucaria BidwiUi 0*077% 



Actinostrobus pyramidalis 0*077 % 



Podocarpus elata 0*002% 



Dacrydium Franklini 0'129% 



Athrotaxis selaginoides 0'019 % 



Phyllocladus rhomboidalis 0-145 % 



Air-dried black gum of Agathis robusta 0-0046 % 



Araucaria Cunninghamii 0*0038 % 



Baker and Smith assume that manganese is essential to the pro- 

 duction of the most complete growth of Coniferae. The element is 

 found in these plants even when they grow on soils containing only 

 traces of manganese and it is suggested that possibly the excess or 

 deficiency of manganese in the soil helps to govern the location of certain 



