67 



Melilotas officinalis. F. Bjernemose; Falst. Korselitse. Trifolium procumbens. 

 S. Tisvilde Hegn. Trifolium minus. J. Skive!. Trifolium repens. Common f. 

 inst. Skaarup '"'/s 70. Trifolium hybridum f. inst. 0rsl0v (P. N.). Trifolium 

 arvense. F. Ulkendal; S. Rervig, Tisvilde Havstok. Trifolium striatum. J; Skive!, 

 Fredericia Void (Jak. Lge). Trifolium incarnatum. S. 0rsl0v (P. N.). Trifolium 

 pratense common (Rostrup has found the attack of the fungus often causing 

 the affected plants to form several quartered or quinquepartite leaves). Tri- 

 folium medium common. Trifolium alpestre. S. Jonstrup Vang. Medicago sativa 

 common. (M. L. M. 07 '''^). Medicago lupulina. S. Kabenhavn. Lotus cornicula- 

 tus. J. Skagen (Exc. ''^/t 96), Gaardbogaard; S. Ruderhegn (C. H. O.). Lotus 

 uliginosus. J. Viborg ! . 



73. Peronospora ononidis Wilson 10^'*. 



The form on Ononis is by Rostrup (in herbario) called Perono- 

 spora ononidis R., but in Thiimens Mycot. No. 616 it is called Per. 

 viciae and Fischer calls it Per. trifoliorum. 



Ononis spinosa. F. Skaarup (June 76 Exs. Thiimen mycot No. 616), Sven- 

 borg (20/6 72). Ononis repens. J. Nibe!, Knudby!; F. Klingstrup; S. Frede- 

 rikssund ! . 



74. Peronospora cytisi Rostrup (92 j &. p), Syn: Per. cytisi Mag- 



nus (Hedwigia 1892 i"^), Syll. XI 

 laburni vulgaris Voss in Thiim. 

 Mycot. No. 2219, Guldregn- 

 skimmel (R 02 a 2°= 6. R 04 a 1'). 



At the same time as Rostrup 

 O. Kirchner (92) found it in 

 Wurtemberg and P. Magnus in 

 France (P. Mg. 93); about 10 

 years before W. Voss found it 

 in Laibach in Austria; Rostrup 

 was, however, the first to deno- 

 minate and describe it. It has 

 been found several times in 

 nurseries on about ' 10 species 

 of cultivated Cytisus, particu- 

 larly affecting the young plants 

 which will quickly be killed by 

 it (R 92 j «"). June-August. 



The colour of the clusters of 

 the fungus is ash-grey on the 

 underside of the leaves, the cor- 

 responding spots on the upper- 

 side are brown. 



The conidiophores are regu- 



Per. trifoliorum de By. form. 



Fig. 3. 



1, Leaf of Cytisus laburnum with Peronospora 



cytisi Rostrup. 2, conidiophore with conidia. 



3, oospores. From R. 02 a. 



5* 



