IOWA academy of sciences 
89 
SOME DISEASES OP ROCKY MOUNTAIN PLANTS. 
BY L. ir. PAMMEL. 
Introduction. 
Plates Vll-Xir. 
Only a very small beginning lias been made of the study of the para- 
sitic fungi of the Rocky Mountain Region. A large number of interest- 
ing parasitic diseases affecting the cultivated plants, trees and shrubs, 
as well as herbaceous plants, occur in the Rocky Mountain region. The 
diseases that I have discussed constitute only a small part of those occur- 
ring here. 
About a year ago the writer prepared a paper on the Cedar Apple 
Fungus and Apple Rust in Iowa, in which he referred to the more impor- 
tant apple rusts found in the Rocky Mountains. By permission of the 
chief of the Division of Vegetable Physiology and Patholog;^^ the writer 
used that portion of the paper containing Rocky Mountain species of 
Gymnosporangia and Roestelia prepared for that Division some years 
ago. In this connection I desire especially to express my thanks to Dr. 
Albert F. Woods and Mrs. Patterson of the Division for the many 
favors shown me in the preparation of this paper. I have therefore 
omitted from the present paper a discussion of the species of Gymnos- 
porangia. 
PfiRiDEPMiuM, Lev. 
Among the parasitic fungi of conifers none are more destructive 
than members of the genus Peridermium, first distinguished as a genus 
by Leveille^ on characters given by Link-. The European species have 
been much more carefully studied with reference to their genetic con- 
nection than our own^ The only American writer who has studied our 
species with reference to their relationship is Farlowb We are indebted 
to DeBary® for our knowledge of the biology and life history of Ghryso- 
myxa rJiododendri that produces its teleutospcres on Rhododendron and 
the aecidium stage, Peridermium al)ietinum or Aecidiuyn aMetinum, on 
P . excelsa. The autoecious Ghrysomyxa ahietis is common in Europe on 
Picea excelsa. Other forms like Peridermium {Aecidium) columnar e are 
connected with Galyptospora goeppertiana Kuhn. Von Tavel’s account 
is simply a summary of work done by others®. 
1. Mem. Soc. Linn. d. Paris. 4; 212. 1820. 
2. Willdenow in Linn. Sp. PI. 6 : GO. See also Pries Summa Veg. 2 : 510. 
8. Rees. Die Rostpilzformen der deutchen Coniferen. 80. 
4. Notes on the Cryptogamic Flora of the White Mountains. Appalachia. 
3 : 322-251. Notes on some species of Gymnosporangium and Ghrysomyxa of 
the United States. . Proc. Amer. Acad. Arts and Sci. 20 : 311-323. 1885. Abst. 
Jour. Myc. 1 : 45. 
5. ot. Zeit. 37 : 700, 777. 801, 825, 841. pi. 10. 1870. See also DeBary 
Comparative Morphology and Biology of the Fungi Mycetozoa and acteria Engl. 
Trans. Garnsey & Bulfour. 283. Oxford. 1887. 
0. Hartig. Lehrbuch der Baumkerankheiten. 5G. Hartig. Textbook 
of the Diseases of Trees. Engl. Trans. Sommerville and Ward. 161. 
Tubeuf. Pflanzenkrankheiten. 383. 
Von Tavel. Vergleichende. Morphologie der Pilze. 123, 132. 
