Exobasidium 



THELEPHORACE^: 



423 



normally tetrasporous, but spores sometimes varying in number from 

 one to five. The hymenial cells are borne on vegetative hyphae 

 which grow in the cellular tissue of the host and form a loose stratum 

 on its external surface. Spores ovate to elongate-oval, continuous, 

 rarely becoming septate, colourless. (Fig. 103.) 



Most nearly allied to Cortirium, but differing in the absence of 

 a sporophore or subiculum and in being parasitic. Exoascus, an 

 Ascomycetous fungus, sometimes grows in company with Exobasidium. 



Species 1899, 1900 



1899. E. Vaeeinii Woron. (from its growth on Vaccinium and its 



allies) a b c. 



Innate, effused, usually orbicular or elongate, often confluent. 

 Hym. on under surface of leaves and round stems, pale rose, 

 covered with a white bloom. 



June-Aug. ^ n - ^ e( ^ or P ur ple patches occur on the upper surface of the 

 leaves, opposite to the portion occupied by the fungus below. 



1900. E. Rhododendri Cramer (from its growth on Rhododendron} a c. 

 Forming gall-like bullate excrescences, at first pale, then reddish 



and shining on stems, petioles and under surface of leaves. 

 On Rhododendron ferrugineum, R. hirsutum, R. Wilsonii. July. I in. 

 Insects, mites, etc., are often found in the gall-like swellings of 

 Exobasidium . 



LXXXIX. CYPHELLA Fr. 



(From the usual shape, like a small goblet, Gr. kuphos.) 



Usually small, sometimes almost minute, somewhat membranous, 

 cup-shaped, rarely plane, adnate from a central or oblique point, 

 sometimes with a stem and pendulous. 

 ffymemum within the cup or disc. Basi- 

 dia tetrasporous, rarely bisporous. Spores 

 subovate. (Fig. 104.) 



Closely allied to Solenia. C. per- 

 pusilla is intermediate. Owing to the 

 strong external resemblance in many 

 Cyphella to certain small species ofPeztza, 

 a genus of Ascomycetous fungi, it is 

 necessary to examine microscopically 

 the hymenium of some of the species 

 for the decisive characters of basidia 

 or asci. C. faginea Lib. is British, 

 but it is an Ascomycete. 



Species 19011922 

 Stipitate. 1901 1905 



Sessile or subsessile. 



Fig. 104. A. Cyphella brunnea 



Spores hyaline. 1906 1918 Phm., x 2. B, ditto with c, sec- 



Spores coloured. 19191922 %* I0 " D ' basidium and spores ' 



