326 THE BASIDIOMYCETES 



of teliospores, their shape, and their septation are among the 

 characters used in generic separations. In the Pucciniaceae the 

 tehospores are borne on a stalk or pedicel, whereas in the Alelamp- 

 soraceae they are sessile and arranged in layers or in columns. 



The feature that most strikingly separates teliospores from 

 other types of rust spores is their method of germination. Among 

 many pedicellate species each cell of the teliospore has a single 

 germ pore, through which a short germ tube emerges. This germ 

 tube has a limited growth and is called a promycelium or ba- 

 sidiuni. It usually becomes 4-celled by transyerse septa. It never 

 functions as an infection hypha. From each basidial cell a 

 sterigma arises, supporting a sporidium or basidiospore that is 

 discharged at maturity and is air-borne. 



Among certain melampsoraceous species germination of telio- 

 spores follows a somewhat different plan. In Coleosporium, 

 Ochrospora, Trichospora, and Chrysopsora, for example, mature 

 teliospores are single-celled but on germination become 4 super- 

 imposed cells, each of which bears a long sterigma that abstricts 

 a sporidium. In certain other genera, such as Melampsora, 

 Chrysomyxa, and Cronartium, each superimposed cell forms a 

 4-celled promycelium and 4 sporidia. This same type of germi- 

 nation occurs in Phragmidium, which has pedicellate spores. The 

 basidia of Ravenelia may bear only a single sporidium. Another 

 unusual kind of germination occurs in Barclay ella dejonnans on 

 Ficea morinda in the Himalayas; in this species each cell of the 

 tehospores forms a promycelium, each segment of which rounds 

 up and is the sporidium. 



Other noteworthy teliospore types occur in certain short- 

 cycled rusts. In species of Endophyllum the teliospores are borne 

 in cupulate structures in aecioid chains and are morphologically 

 like aeciospores. In fact, they were regarded as aeciospores by 

 early workers. On germination, however, the Moreaus (1919) have 

 shown, promycelia and sporidia are produced. Sappin-Trouffy 

 (1896) showed that E. sempervivi and E. eiiphorbiae-sylvaticae 

 have binucleate tehospores and that their nuclei divide conju- 

 gately. This condition may not occur invariably, and other 

 species of Endophyllum may behave differently [Ashworth 

 (1934)]. Kimkelia nitejis produces caeomoid telia. Kunkel 

 (1913, 1914) and Dodge and Gaiser (1926) have given considera- 



