MISSOURI BOTANICAL GARDEN. 



If one considers the manner in which a fungus disease 

 attacks plants at the present day, one will find that closely 

 related plants are apt to be afflicted by the same disease. 

 Thus Plasmopara Cubensis grows on a large number of 

 genera of the Cucurbitaceae ; Gymnosporangium Nidus Avis 

 (Aecidium) on several genera of the Pomeae (Rosaceae) ; 

 Trametes Pini on several genera of the Coniferae, and so 

 on. Judging by analogy, one might expect genera nearly 

 related to Taxodium to be diseased similarly to Taxodium. 

 There are but a few genera, closely related to Taxodium , 

 which grow at the present time. In North America: 

 Taxodium mucronatum is found in Mexico; /Sequoia 

 gigantea and $. sempervirens , in California; Libocedrus 

 decurrens, in California and Oregon; and the less closely 

 related species of Juniperus. In addition to these there 

 are a number of other species scattered over the globe, 

 thus Libocedrus Douiana and L. Bidwillii in New 

 Zealand, Libocedrus cupressoides and L. Chilensis in 

 Chili, also a dwarf species in Iceland. A closely related 

 tree, Glyptostrobus Europaeus, is found in some of the 

 southeastern provinces of China. All of these trees were 

 common over the whole earth in Tertiary times, and if a 

 disease was common to them then, one might expect to find 

 that to-day. Of the species enumerated, the Sequoias are 

 apparently free from diseases of the wood * while Libocedrus 

 decurrens and the species of Juniperus so far seen, are affected 

 by diseases which cause local rotting of the wood much like 

 that of the cypress. Of the other trees nothing is known 

 so far. The fungus which causes the decay in Libocedrus 

 is described in the following, while that found in the trunks 

 of Juniperus species is to be described in a separate paper 

 soon to appear. 



* Sargent, C. S. Silva of North America 10 : 140. 1896. 

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