178 Rev. M. J. Berkeley and Mr. C. E. Broome on British Fungi. 



544. Oidium Tuckeri, Berk, in Gard. Chron. 1847, p. 779 

 cum ic. On the leaves, young branches, and fruit of vines. 

 Extremely common and destructive. 



A form or species with still larger spores occurs on Chrysan- 

 themujn Indicum. 



545. O. abortifaciens, Lk. On the spikes of grasses, causing 

 the diseased state of the ovule known under the name of Ergot. 

 The production has been referred to a new genus Ergotetia, but 

 not, we think, with sufficient reason. 



546. 0.j[)orn^mw, Mont. MSS.; Robin, tab. 4. fig. 10. On 

 the scales of Porrigo lupinosa, Bristol, H. 0. Stephens. 



547. O. concentricum, nob. = Cylindros])oriwn concentricum, 

 Unger, Exanth. tab. 3. fig. 9 =-Fusispoi-ium Urticce, Desm. no. 930. 

 On leaves of various plants : common. 



A variety of forms, as Fusisporium calceum, Desm., on ground 

 ivy, F. UrtictB, Desm., on nettles, another on violets, primroses, 

 lettuces, docks, Trientalis, Helleborus, Ranunculus, &c. occur, 

 scarcely differing from one another. These are what Unger 

 considered as Cylindrosporium concentricum, Grev. That is how- 

 ever a very different thing. 



Should it be found that the various forms present really distinct 

 characters, the species may be separated. At present however it 

 appears best to include all in one comprehensive name. In all 

 the forms we believe that the threads protrude through the sto- 

 niata. Amongst the spores, some occur which are larger and uni- 

 septate. It is possible that after the spores fall they may increase 

 in size, as is, we believe, the case in many fungi, as in the genera 

 Cladosporium, Fusisporium, &c., and as is ascertained to be the 

 case in Elaphomyces. 



548. Fusisporium bacilligerum, n. s. Griseo-album, hyphasmate 

 obsoleto, sporis longissimis 5-7-septatis deorsum attenuatis apice 

 subclavatis. On leaves of Alaternus, West of England. 



Occupying the centre of little brown spots. Hyphasma obso- 

 lete; spores very long, hyaline, 5-7-septate, strongly attenuated 

 below, obtuse and slightly clavaeform above, somewhat curved. 



A very distinct species, remarkable for its spores, which I'c- 

 semble in fonn those of Hymenopodium sarcopodioides, Corda. 



549. F. roseolum, Steph. MSS. sub Fusidio. Roseohmi, floccis 

 brevibus ; sporis curvis elongatis 3-6-septatis. On decayed po- 

 tatoes, Bristol, H. O. Stephens. 



Of a delicate rose-red, forming thin floccose patches ; fertile 

 threads short. Spores curved, elongated, slightly obtuse, 3-6- 

 septate, often slightly projecting at each dissepiment. 



This approaches Dactylium, especially in the rosy tint which 

 is so common in that genus. The spores however are those of a 

 Fusiroorium, 



