NOTES ON RECENT EESEARCH. 



501 



author examined and describes the special peculiarities of eighty species 

 of Aspalathus, two species of BucJienroedera, seven species of Melolohium, 

 two species of Dickihis, and the f^ingle species of Heylandia. A key is 

 given of the important histological characters in the leaf and stem, and a 

 short description of the important anatomical characters of all the species 

 considered. The paper occupies fifty-four pages, and is not illustrated. 



G. F. S.-E. 



Asparagus Rust. 

 Asparagrus Rust in Massachusetts. By G. E. Stone and R. E. 



Smith (BiilL 61, Mass. Agri. Coll. ; April 1899). 



The Asparagus rust is caused by a parasitic fungus, which was named 

 Pnccinia Asparagi by the elder De Candolle nearly a century ago. 



The Asparagus rust has occurred in Europe for some centuries, but 

 the exact time that it was introduced into this country is unknown. 



The rust was first called attention to as occurring in the Eastern 

 United States by Professor Hals ted, of New Jersey, in the autumn of 

 1896, although there is a possibility of its having existed on Cape Cod 

 one or two years previous to that time. 



The severe outbreak of the Asparagus rust is due to conditions of the 

 plants, brought about largely by the excessive drought during the seasons 

 of 1895 and 1896, and in all probability the severity of the attack was 

 aggravated to some extent by the excessive rains of 1897. 



The rust as an injurious factor has been limited to only a few places in 

 Massachusetts, although especially affecting the Asparagus regions. 



The injurious effects of the rust have been confined to dry sandy soils 

 possessing little capacity for holding water. Where the soil is heavier, 

 possessing more water-retaining qualities, the rust has caused no per- 

 ceptible harm. 



The injurious effect of the rust is apparent only when the summer 

 stage occurs, viz. the red spores or uredospores, which develop during 

 July and August. 



The autumnal stage of the rust, known as the black or teleutospores, 

 has been prevalent all over Massachusetts since 1896, but this form has 

 caused no appreciable harm and is disappearing. 



The loss experienced from rust in Massachusetts this season, caused 

 by the severe uredospore infection of 1897, was from 15 to 80 per cent, 

 in the yield of the marketable crop. The average loss will equal 20 to 25 

 per cent. 



The practice of burning the affected tops in the summer has resulted 

 in injury, and no benefit has manifested itself from burning in autumn. 



The results obtained by spraying are not encouraging. 



The various asparagus-beds on moist soils do not appear to be affected 

 with the summer stage of the rust, and consequently are not injured, 

 being able, as it were, to resist the summer stage, although the tops of the 

 plants are affected with the autumnal stage during their period of natural 

 death. 



The best means of controlling the rust is by thorough cultivation in 

 order to secure vigorous ])lants, and in seasons of extreme dryness plants 



