THELEPHORACEAE 



343 



Kordyana, causing necrotic spots on tropical species of Com- 

 melinaceae, forms fascicles of basidia and sterile hyphae that 

 emerge from the stomata. The basidia are variable in form and 

 are 2-spored. From illustrations of K, polliae in the study by 

 Gaumann (1922), this genus may 



well be judged to be related to /^\ /^ /^ /^^ 

 Microstroma, which appears to 

 be established among the Fungi 

 Imperfect! [Wolf (1929)]. 



Thelephoraceae 



L 



L 



4 



t 







Fig. 129. Stages in formation of a 



clamp connection. The dicaryotic 



cell is a hyphal tip, and nuclear 



division is conjugate. 



This family contains approx- 

 imately 20 genera and 1000 spe- 

 cies of membranaceous to leath- 

 ery fungi in which the hymenial 

 surface is smooth or only slightly 

 contoured. Under the title "The 

 Thelephoraceae of North Amer- 

 ica" Burt (1914-1926) published 

 a series of taxonomic papers, 

 the most comprehensive treatise 

 extant on the family. Many Thelephoraceae are important causes 

 of decay in woody plants. 



The sporocarps vary in shape from crustose or resupinate to 

 bracket-shaped or funnel-shaped structures with the hymenium 

 on one surface only. Sterile elements occur interspersed with 

 basidia in a few genera, such as Aleurodiscus; in Peniophora and 

 Hymenochaete they are sharp-pointed, whereas in Asterostroma 

 they are stellate. These sterile elements are given different names 

 based on shape and consistency. If they are hair-like, they are 

 cystidia; if thickened and awl-like, they are setae; and corneous 

 or gelatinous gloeocystidia. The nature of the sterile elements 

 is taken into consideration in the separation of genera and of 

 species. 



Little consideration has been given the developmental mor- 

 phology of Thelephoraceae except in a few species. Corticiinn 

 vagUTfi, widely known as a stem and root parasite of many kinds 

 of economic plants, forms its oval basidia sparsely on an arach- 



