32 Notes on Parasitic Ascomycetes. — III. [Sess. 



triviale ; Ps. radians (Eob.) Sacc, on various species of Cam- 

 panula ; Ps. medicaginis (Lib.) Sacc, on various species of 

 Medicago ; Ps. calthce (Phil.) Mass., on dark spots, especially 

 on the lower surface, of leaves of Marsh Marigold (Caltha 

 palustris) ; and Ps. alismatis (Phil. & Trail) Sacc, on fading 

 leaves of Water Plantain (Alisma Plantago-aquatica). 



In many parts of the country the Wood Anemone (Anemone 

 nemorosa) is attacked by Sclerotinia tuberosa (Hedw.) Fckl., a 

 parasitic Discomycete. It appears to affect the underground 

 rhizomes of the host-plant, some of which are converted into 

 sclerotia closely resembling rhizomes themselves in size and 

 colour. Each of the ascophores developed from the sclerotia 

 grows upward, and pushes its way to the surface of the 

 ground by means of a long slender stem, surmounted by a 

 dark-brown cup. The latter is at first top-shaped and closed, 

 but becomes funnel-shaped, and at length is so fully expanded 

 as to appear almost flat. This fungus also occasionally occurs 

 as a destructive parasite on other species of Anemone culti- 

 vated in gardens. 



Among forms parasitic on cryptogamic plants, the only 

 species to be noticed is Helotium marchantice (Berk.) Fr., 

 recorded as growing in England on fading specimens of 

 Marchantia polymorpha, one of the Liverworts. In Scotland 

 it is apparently represented by the var. conocephali Boyd, 1 

 which has been reported from various parts of the country. 

 The Scottish variety occurs on Conocephalum conicum, and 

 produces somewhat thick, pale yellowish-brown ascophores, 

 seated on faded pallid or brownish spots on the living thallus 

 of the host. It is distinguished from the type by its larger 

 spores and different habitat. This may probably be the same 

 as the H. marchantia* Berk., reported many years ago by the 

 late Mr A. Jerdon as growing on fading Marchantia conica 

 at Jedburgh. 2 



Several species of Sclerotinia, &c, are truly parasitic in 

 their earliest stages, and occur as destructive moulds, &c, on 

 various living plants. These, however, are not particularly 

 noticed here, as they lie beyond the limits to which our brief 

 survey was restricted in the first paper of the present series. 



1 'Trans. Brit. Myc. Soc.,' vol. iii. p. 113. 



2 'Mycologia Scotica,' No. 1718. 



