OPEN LETTERS. 125 



out the Bay region. It often becomes a serious pest, especially 

 during the wet winter- months, and florists find^ their only safeguard 

 is to avoid excessive moisture and renew their stock frequently with 

 young, uninfected plants. — W. C. Blasdale. 



OPEN LETTERS. 



I SEND you by to-day's mail, under separate cover, a species of 

 thistle [Centaurea solstitialis Linn.], that is a very obnoxious weed, 

 hurtful to growing crops, and that often kills horses, which eat it, 

 when matured and dry. It will grow on good land, uninterrupted, 

 to the height of three to four feet, and so thick^ that you can not 

 force a team and mowing-machine through it. To mow it does not 

 kill it, it seems only to improve its productiveness for seed; neither 

 will flooding the ground kill the seed. ... I have known 

 flood-water to remain on the ground for four months, two feet deep, 

 and the thistle to grow after the water receded. . . . It is 

 locally called "Buckthorn" and "Russian Thistle." 



W. R. MUMMA. 



Grand Island, Colusa Co., Cat, September 3, 1897. 



MISCELLANEOUS NOTES AND NEWS. 



Count Victor Trevisan, an Italian cryptogamist, died April 

 18, 1897, at Milan. His writings were largely algological. 



In advance of the eighth annual report of the Missouri Botan- 

 ical Garden we have as a separate "The Mosses of the Azores and of 

 Madeira," by C. Cardot. 



The Berlin Academy of Sciences has recently awarded nearly 

 $20,000 to scientific investigators. Prof. Adolf Engler, of Berlin, 

 received 2,000 marks for the publication of monographs on African 

 botany, and Dr. G. Lindau, 900 marks for studies on lichen. 



Plans are now being prepared for an enlargement of the Mis- 

 souri Botanical Garden. There is to be added a tract of some 

 eighty acres, which will be mainly used for synopses of the flora of 

 North America and the flora of the world, one plan following the 

 arrangement of Bentham and Hooker, the other that of Engler and 

 Prantl. 



