SYNCHYTRIUM. 



109 



less swollen neighbouring epidermal cells. The sporangia contain 

 reddish-yellow drops of oil, so that the swellings appear yellow. 

 The organs attacked are much 

 distorted and more or less 

 stunted. 



The same fungus occurs on 

 other Compositae, and is pro- 

 bably identical with S. san- 

 ffuineum of Schroeter, which 

 produces dark red, crusty swell- 

 ings on Cirsium palustre and 

 Orepis biennis. 



Along with S. taraxaci one 

 often finds Olpidium simulans. 



S. fulgens, Schroeter (U. S. 

 America), produces reddish- 

 yellow swellings on the leaves 

 of Oenothera biennis and 0. 



, . Fio. 25. — Synchytmum taraxaci. Leaves of 



muneata ; when reSting-SpOreS laraxaami officinale so deformed by the fungus 



,., n ^ , that the laminae are all more or less undeveloped. 



appear they form brown crusts, (v. Tubeuf phot.) 



The sori of zoosporangia are 



detached from the host-plant as single sporangia, which 



become scattered over the leaves. 



S. trifolii, Pass. ( = Olpidium trifolii, Schroeter), is as yet 

 little known. 



Other American species are : — 



S. papillatum, Farl., on Geranium. 



S. decipiens, Farl., on Amphicarpaea. 



S. vaccinii, Thomas,^, on Vaccinium, Gaultheria, Kalmia, 

 Hhododendron, etc. 



Pycnochytrium. 



The sori of zoosporangia are not produced directly from the 

 mature sporophore, but the contents of the sporophore pass out 

 by a fine opening and form a thin-walled vesicle, the protoplasm 

 of which breaks up into sporangia. 



Schroeter divides the genus into two sub-genera. 



(A) Mesochylrium. The discharge of the original sporophore 



^Halsted, " Cranberry gall-fuDgus " ; N. 

 1889. With figiires. 



Jersey Agric. Coll. Bullet. 64, Dec. 



