IOWA ACADEMY OF SCIENCES 
97 
Eco^’omic Go:<i)ttioxs. This fungus dees serious injury to the young 
tree cr branch. Not only is this true of the Uintah and Big Horn moun- 
tains but also as noted by Underwood and Earle, in Alabama where it 
does much damage to pines. The writer saw numerous small trees in 
the Uintah mountains ihat v:ere very much dwarfed owing to the pres- 
ence of this fungus. A part were nearly and some entirely killed by 
the parasite. The fungus mycelium penetrating the tracheids checks 
the flow of water and with the resin of the injured cortex check, trans- 
portation of the elaborated food products ef the plant so that they do 
not reach the root, hence the root development is feeble. Owing to the 
unfavorable conditiens existing in this region the growth of conifers is 
slovv^, hence it is important to properly m.aintein their root systems. 
PeriderTnium elatium (AJh. ■& Schw.) Kiinze and Schm. 
Histoky. Albertini and Schweinitz^ first described the fungus which 
they found on Picea excelsa as Aecidium elatium. Link/ however, 
referred the fungus to Gaeoma elatium but Kimze and SchmidU 
placed the fungus in the genus Perldermium. Saccardob , Winter^ 
and Schreeter** do not consider the species as definitely connected with 
a teleuto form and therefore they retain the Albertinian and Schweinii- 
zian name of Aecidium elatinum. 
UeBary' described the parasitic nature of this fungus in 1867. From 
an economic standpoint it has been treated by Rees®, Hartig“, TubeuP^ 
Ward^^ and FranlPu Special attention should be called to Heck’s^® mono- 
graph. Reference to the American occurrence of the fungus has been 
made by Farlow^^ Peck^^ SargenP® and Anderson^b 
General Characters. The parasite causes the so-called witches’ 
broom or “hexenbesen” of the Germans. The distortions vary in size from 
a few inches to three feet in circumference and are from a few inches to 
three feet high. A single tuft or several may occur on a tree, being some- 
times so numerous as to badly disfigure the same. One writer describes, 
them as follows: “so that the distortion which can be seen from a con- 
siderable distance looks like small trees attached to the branches.” The 
shoots are erect and rise from dense vertical tufts, the development of 
the lateral and latent buds giving rise to the formation of the bird’s nest 
distortion. The large scars of the leaves of previous years are promi- 
nent. The leaves spread on all sides giving the bunch a peculiar appear- 
ance. These abnormal leaves are nearly horizontal. They are thicker 
1. Conspectus Fungorum. 121. PI. 5 f. 8. 1905. 
2. Sp. PI. L : 06. 1825. 
8. Die Schwamme. 141. 
4. Sylioge Fungorum. 7 : 825. 
5. Die Ihlze Deutsclilands. Oesterreiches und der Schweiz. 2G1. 
6. Die Pilze Schlesiens. 381. 
For exsic. see Fuckel Fung. rhen. 290. Kunze Fungi Sel. 555. liabenh Fung. 
Kurop, 896. Herb. Myc. 388. Linhart Fung. Hung. 142. 
7. Bot. Zeit. 25: 257-264. 1867. Aug. 16. 
S. liber den Krebs and die Hexenbesen der Welsstaune (Ahics pcclinatta DC. 
9. Textbook of the Diseases of Trees. 179. 
10. 1‘flanzenkrankheiten. 417. 
11. Diseases in plants. 116. 
12. Die Krankheiten d. Planzen. 2 : 209. 
18. Der Weissannenkrebs. Berlin. Julius Springer. 1894. 
14. Appalachia 3: 240. 
15. Bep. N. Y. St. Mus. of Nat. Hist. 27 : 204. 28 : 86. 
16. Silva. 12 : 101. 
17. Bot. Gazette. 24 : 309. 
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