COLEOSPORIUM. 377 



occur oil various species of Sonchv.s (witliout doubt on ^S". 

 arvensis). Aecidia are unknown. He relates it to Feridi'vininm 

 Fischeri Kleb. on needles of Finns si/Ivestris. 



C. synantherearum Fr. A provisional collective name for 

 aecidia on Adcnostyh's, Fdasites, Cacalia, Scnccio, etc., the life 

 history nf which is as yet unknown. 



C. campanulae (Pers.) (Britain). Uredo- and teleutospores 

 on Campanulaceae (Campanula and Fhyteuma). The aecidial 

 form is Frriderminm Rostrupii on pine-needles. 



C. pulsatillae (Str.). Uredo- and teleutospores on Anemone 

 Fiilsafilla and A. p)ratcnsis. Aecidia unknown. 



C. ipomoeae (Schwein). Uredo- and teleutospores on species 

 of cultivated Ijmnoea in United States. Aecidia unknown. 



Fischer^ obtained pycnidia on needles of pine by infection 

 witli a Coleosporium from Cetmpanvla Traehelinm. 



Chrysomyxa. 



The teleutospores are formed closely together in yellow sori ; 

 each spore consists of an acropetal series of cells, the distal 

 one of which, without leaving the sorus, germinates to produce 

 a promyceliuin of several cells. Uredospores are not always 

 present. The ai-ridia hww well-developed peridia. 



Chrysomyxa rhododendri (D. C.).- This is a common rust 

 on the Alps where the Alpine-rose {Rhododendron ferriKjincum and 

 R. hirsutum) occurs. Immediately after the break-up of thia 

 winter little dark-red cushions of this rust appear on the uuder- 

 .side of the leaves. These contain the. sori of teleutospores 

 already partially developed during the previous autumn, and 

 now, after hibernation, ready to increase in size and to rupture 

 the host-epidermis (Fig. 211). The teleutospores so exposed 

 geniiinate without leaving the sorus, and produce four-celled 

 proniycelia, with sterigmata, from each of which a single 

 sporidium is abjointed. The sporidia make their escape in 

 June, and aligliting on the unfolding needles of the spruce 

 {Picca exccha), they germinate at once and produce Accidinm 

 ahietinum, the blister-rust of the spruce (Fig. 212). 



An intercellular mycelium is developed in the spruce-needles, 



^ Botan. Centralblatf, lix., 1894. 

 -De Bary, Botan. Zeihuig, 1879. 



