62 



SCIENCE. 



[Vol. XXII. No. 548 



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NOTES ON THE OCCURRENCE AND DISTRIBUTION OF 



UREDINE^. 



BT M. A. CAKLETON, KANSAS AGRICULTURAL EXPERIMENT STATION, 

 MANHATTAN, KANSAS. 



Very little attention has been given to the distribution of para- 

 sitic fungi, except so far as to note their occurrence on host-plants 

 of more or less close relationship, and that they are usually some- 

 what more abundant in wet seasons and places than in those that 

 are dry. But close observation reveals more facts than these, and 

 some that are peculiarly interesting. 



Strictly speaking, the parasitic fungi are affected by but two 

 of the elements of environment concei'ned in the distribution of 

 phanerogams. These are temperature und inoisture, while flower- 

 ing plants are also affected by differences in kind of soil and 

 amount of light 



However, there is a kind of distribution of parasitic fungi, 

 scarcely to be called geographical, although such distribution has 

 probably been caused by changes in the anatomy and physiology 

 of the host, which changes were themselves caused by variations 

 in soil and climate I refer to cases of certain hosts which sup- 

 port certain fungi in one locality and not in another. Of course, 

 it may be said that in one or more of these localities there has yet 

 been no chance for infection, but in numerous oases this is, to 

 say the least, rather improbable, and sometimes the hosts are dis- 

 tributed so as to completely connect these localities, and yet 

 without general distribution of the fungi. Moreover, some of 

 these hosts are annuals, or occasionally biennials, so that it cannot 

 be said that the fungi are prevented from spreading by the cir- 

 cumstance of their being reproduced yearly from perennial 

 mycelium and not by infection by germinating spores. 



Again, while a gioup of species (a genus, for instance) in one 

 locality may all be attacked by a certain fungus, in another local 

 ity , where these hosts are all represented, only a part of the group 

 may be affected by the same fungus. 



Certain fungi have also peculiarities of occurrence in point of 

 time. After being reproduced annually for several years, they 

 may suddenh disappear for an indefinite period, or reappear after 

 certain intervals of time. 



In illustration of these general statements, it may be'of interest 

 to give here some observations that I have made on the distribu- 

 tion of Uredineae in Kansas, covering a period of about six years. 



In the first place, it seems to be true that Aecidia require more 

 moisture than the other stages, and telentospores the least. In 

 Kansas, east of the 96th meridian, the species of Aecidia number 

 about fifty, and telentospores (of all genera) sixty-five; while west 

 of the same meridian tiie proportion is about twenty-three of the 

 former to fifty of the latter. The telentospores of western Kansas, 

 it is seen, are more than twice the Aecidia. The difference in 

 rainfall of the two portions is well known. But all Uredineee are 

 probably more abundant in wet seasons than in dry seasons, and 



also more abundant in warm seasons than in cool seasons. This 

 season has been much earlier than the preceding one, and has 

 been marked by a number of unusually hot days, alternating with 

 heavy rains. Moreover, the rains have continued to date, and 

 were quite frequent just at harvest time. The result has been 

 a season unusually favorable for rusts. The following species 

 have been collected in large quantities this season: Aeeidiiim 

 peckii., De Toni, on Oenothera biennis; Aecidium euphorbice, 

 Gmel. ; Aecidium violce, Sebum., on Viola falmota, L., var. 

 cucullata, Gr., and cultivated i^ansies; Aecidium zanthoxyli, Pk. ; 

 Aecidium cepholanthi, Pk. ; Puccinia graminis, Pers. II. ; Uro- 

 pyxis petalostemonis (Farl.), De Toni; Roestelia pirata, Thaxt., 

 on Pints coronaria; Uredo cceoma-nitens, Schwein., on Rubus 

 villosus (cult.) and Rubus canadensis. Immense numbers of 

 spermogonia were found with Aecidium peckii, De Toni, and with 

 the Uropyxis, Roestelia, and Uredo cceoma-nitens, Schw., above 

 mentioned. Puccinia graminis, Pers., has been quite destructive 

 to grains, especially oats, over the greater part of the State, but 

 particularly in the eastern jJortion. It is a very interesting fact 

 that, while this species was quite rare last year, it is the predomi- 

 nating rust of grains this year, and has caused extensive damage. 

 Last year Puccinia coronota, Corela, was very abundant on oats, 

 but this year, in repeated examinations, I have been unable to find 

 a single specimen. Even P. rubigo-vera (D. C), Wint., the ever- 

 present grain-rust, is very scarce this season. 



The greatest damage from rust prior to this season that I recall 

 was in 1877, when there was a severe rust scourge over northern 

 Kansas. Many fields of wheat were entirely destroyed, and never 

 harvested. Sulphur-like clouds of spores filled the air and irri- 

 tated the nostrils of the workmen. I had no knowledge of botany 

 then, but a vivid remembrance of the general aj^pearance of the 

 rust, coupled with my present knowledge of the differences be- 

 tween the species, inclines me to believe that it was Puccinia 

 graminis, Pers., that did the damage. I have always doubted 

 the usual statements that P. rubigo-vera is the rust that usually 

 does the damage in this country, and this season the facts in 

 Kansas strongly confirm my opinion. Of course, the last named 

 rust is the more common from year to year, but seldom attacks 

 the stem to any great extent, and, in my own experience, any 

 amount of it on the leaves usually does little damage, but when 

 the stem becomes covered with red powder and finally weakens 

 and falls, and the grain shrivels, and the straw becomes very 

 light, then you may guess that Puccinia graminis is in the field. 

 However, there may be facts from other portions of the countrj', 

 even this season, that furnish contrary evidence, for aught I 

 know. 



The above facts call up further instances of variations in the 

 occurrence of species. The following species, originally known in 

 Kansas, have not, to my knowledge, been reported for several 

 yearsT Aecidium abtindans, Pk. ; Aecidium cassice, E, and K. ; 

 Aecidium sambuci, Schw. ; Puccinia similacis, Schw. ; and Aecidium 

 macrosporum, Pk. During the succession of recent dry seasons 

 they have probably become so reduced in numbers that finally 

 there were not enough healthy spores left to reproduce the species 

 on the following year. In like manner Puccinia solida, Schw. ; 

 P. ieymerioe, Burrill; P. sanicidce, Grev. ; and Aecidium piuncta- 

 tum, Pers., seem to have disappeared. In future wet seasons 

 infection may take place from a distance, and the fungi reap- 

 pear. 



As to migration, Aecidium tuberculatum, E. and K. , has cer- 

 tainly been coming rapidly eastward, until this season it was 

 found at Manhattan for the first time. Uredo gaurina, Pk., seems 

 also to be coming eastward. Puccinia heterospora, B. and C, 

 with its host {Abutilon avicennce), Puccinia xanthii, Schw., var. 

 Ambrosice, Burrill, several varieties of Aecidium compositarum, 

 Mont., and Puccinia microsperma, B. and C, are, without much' 

 doubt, working westward. Others might be mentioned, but the 

 possibility of their having been present for yeai-s already, and 

 overlooked, forbids that we should place much dependence on such 

 observations. 



But a more remarkable phase oC distribution is found in the 

 fact that a number of species known on certain host-plants in 

 western Kansas for a number of years are entirely absent in the 



