154 



Illinois Natural History Survey Bulletin 



Vol. 27, Art. 2 



ployed to identity the accumulated col- 

 lection of plant specimens. Although col- 

 lection, identification, and preservation of 

 vascular plant specimens were curtailed 

 durinji World War II, the herbarium 

 contained 13,749 specimens in May of 

 1Q43 and 17,330 specimens in October 

 of 1946. The abundant collection of plant 

 material in succeedin;^ years has in- 

 creased the number of vascular plant 

 specimens in the herbarium to 70,600. 

 and approximately 8,000 additional speci- 

 mens are on hand to be added to the 

 herbarium. Under present conditions 

 three student assistants are employed to 

 prepare the plant material for placing in 

 the herbarium. A card index is main- 

 tained of all plant specimens. 



The bibliography of Illinois plants, 

 started previous to 1931, is not up-to-date 

 because of lack of funds and lack of as- 

 sistants to examine the literature. 



In co-operation with L. E. \'eager, R. 

 E. Yeatter, A. S. Hawkins, and D. H. 

 Thompson, fellow staff members doing 

 wildlife or fisheries research, botanists 

 made a census of waterfowl food plants 

 of the Chautauqua Drainage District, car- 

 ried on a surve>' of Illinois plants useful 

 to wildlife as food or cover, and con- 

 ducted experiments on propagation of 

 plants useful to wildlife as food or cover. 

 A collection of 848 samples of seeds was 

 developed for identification of seeds in- 

 gested by waterfowl. 



Activities pertaining to the botany of 

 Illinois include preparation of manu- 

 scripts designed for publications, mainly 

 of an educational or popular type. These 

 publications are on such subjects as 

 noxious weeds, directions for the study 

 and identification of plants, drug plants 

 (Tehon 1937^. 1939^/, 1951./), plants poi- 

 sonous to livestock (Tehon, Morrill, & 

 Ciraham 1946), and vegetation of hill 

 prairies in the state (Evers 1955). 



The publication on the vegetation of 

 hill prairies is a report on an extensive 

 ecological study of 61 prairies on the 

 brow slopes of bluffs of the Mississippi 

 River from East Dubucjue to southern 

 Illinois, the Illinois Ri\er from the big 

 bend near Hennepin to Grafton, and the 

 Rock and Sangamon rivers. This type of 

 publication by the Natural History Sur- 

 vey is a continuation of those published 



earlier b\ the State Laborator\' of Nat- 

 ural History. 



Shade and Forest Tree Pathology 



The earliest reported conspicuous dying 

 of trees in Illinois was among the elms 

 in Normal-Bloomington and Champaign 

 in the period 1883-1886 (Forbes 1912«). 

 The next reported conspicuous dying 

 among elms occurred from 1907 through 

 1911, when many trees succumbed in 

 southern Illinois. During this period con- 

 spicuous losses of elms were reported in 

 Cairo, Carbondale, Centralia, Clayton, 

 Du Quoin, Edwardsville, Fairfield, Ga- 

 latia, McLeansboro, Mount Vernon, 

 Quincy, Robinson, Sumner, and Van- 

 dalia. These 14 towns are located in 13 

 counties of western and southern Illinois. 

 Although the cause of the dying of elms 

 during these two periods was not de- 

 termined, it was suggested that some dis- 

 ease might be involved. Dying of feeder 

 roots, wilting of foliage, and dying of 

 terminal twigs was followed by death of 

 the trees. Many of the affected elms in 

 southern and western Illinois were heavily 

 infested with the elm borer, Saperda tri- 

 deniata, and the red elm bark weevil, 

 Magdalis armicoUis, called by Forbes the 

 reddish elm snout-beetle. 



Elm Diseases. — A few years after 

 the establishment of the Section of Bot- 

 any in 1921, reports and inquiries were 

 received about a widespread wilting of 

 elms growing in commercial nurseries 

 and in decorative plantings, most of them 

 in northern Illinois. Some special exam- 

 inations made of these trees by Dr. 

 Christine Buisman of Holland, an expert 

 on elm diseases, revealed that the malady 

 was not Dutch elm disease. Research on 

 the cause and control of this wilting was 

 started in 1930. Until May, 1934, the 

 work was carried on by graduate students 

 — H. A. Harris, Leo C\ampbell, J. A. 

 Trumbower, and A. S. Peirce. In May 

 of 1934 J. C. Carter joined the staff as 

 a full-time plant pathologist to study dis- 

 eases of trees. Although intensive study 

 of the elm wilt problem was continued 

 for se\eral years, other elm diseases and 

 diseases of other species of trees were 

 studied as they became evident. From 1934 

 to 1950 research on tree diseases was 

 carried on by Carter. With the expan- 



