222 BOTANICAL GAZETTE [September 



of this fungus it has been variously named by different workers. 

 In 1849 the name Actinonema rosae (Lib.) Fr. 8 was employed. 

 In 1853 Bonorden 9 described it as Dicoccum rosae, one of the 

 Hyphomycetes. He says that the fungus forms small, closely 

 aggregated pustules of a brown green color which dehisce irregu- 

 larly. From collections made in 1888-1889, Briosi and Cavara 

 distributed the species under the name Marsonia rosae (Bon.) 



1 



Br. & Cav. 10 because they recognized the acervulus type of fruit 

 body which is characteristic of the Melanconiales. The 2-celled 



hyaline conidia suggested its position in the genus Marsonia. 



11 



I have been able to examine the specimens distributed by Briosi 

 and Cavara and have found them to be the same as the rose 

 Actinonema in the United States. The drawing of acervulus and 

 spores which accompany the specimens show the same structure. 12 



Saccardo 13 notes that Marsonia rosae (Bon.) Br. and Cav. 

 resembles Actinonema rosae (Lib.) Fr. This same fungus was 

 described by Trail 14 in 1889 as occurring on roses in Scotland- 

 He called it Marsonia rosae. 



The characters of the genus Actinonema have changed from time 

 to time since the genus was established by Persoon. 15 He applied 

 the name to those forms on leaves and stems having radiate sterile 

 mycelial strands. He describes two species, A. crataegi and A. 

 caulincola, in neither of which perithecia or conidia were observed. 



In 1828, Fries 16 included two species in the genus Actinonema, 



8 Fries, Elias, Summa veg. Scand. 424. 1849. 



9 Bonorden, H. F., Beitrage zur Mykologie. Bot. Zeit. 282. pi 7. fig- 2 - l8 53- 



10 Briosi and Cavara, Funghi parassiti delle coltivate od utile, n. 97- 1889. 



11 La natura degli acervuli fruitifera, subcutanei ed erompenti, ci induce a 

 riferire questo funghetto ai Melanconiei sezione delle Didymosporee Sacc. ove trova 

 riscontro nel genere Marsonia pure a spore didime e jaline. 



12 Type material was received through the courtesy of the Bureau of Plant Indus- 

 try, U.S. Dept. Agric. I am greatly indebted to Miss Ethel C. Field of the same 

 Bureau for some notes on the specimens. She finds that there is no apparent differ- 

 ence between Marsonia rosae of this collection and other European material which is 

 labeled Actinonema rosae. 



13 Saccardo, P. A., Syll. Fung. 10:477. 1892. 



14 Trail, J. W. H., Micromycetes of Inveraray. 46. 1889. 



15 Persoon, C. EL, Mycologia Europaea 1:51-52. 1822. 



16 Fries, Elias, Elenchus Fungorum. 151. 1828. 



