Heteropuccinia. 165 



this fungus occurs on LoUimi pcroinc, which it does abundantly in 

 this neighbourhood, it is accompanied by a profuse development of 

 uredospores, and only in the autumn, from September to November ; 

 whereas the P. coronata on Dactylis is an early summer species, with 

 a much less free development of uredospores. P. corotiata is dis- 

 tinguished from all other British species by its coronate teleutospores, 

 which are surmounted by a crown of digitate processes ; these, being 

 outgrowths of the spore-membrane, and not of the epispore, are dark 

 brown in colour. What their precise function may be is unknown, 

 but they appear, for one thing, to hold the spores together, so that they 

 may be regarded in part as organs of attachment. Sometimes these 

 processes are not confined to the summit of the spore, but extend 

 downwards, gradually becoming smaller, as far as the septum. Such 

 spores show the transition towards the American species, P. aculeata, 

 Schw. Winter has described a coronate Uromyces, U. digiiata, from 

 South Australia ; and Ellis an American Puccinia, P. digttata, on 

 Rhamnus crocea from California. 



Puccinia sessilis. Schneider. 



j^cidiospores — Pseudoperidia on pale roundish or elongated spots, 

 circinating, cup-shaped, with broad, torn white edges. Spores 

 subglobose, smooth, orange-yellow, 18-25 >< 13-20/i,. 



Uredospores — Sori small, elliptical or linear, scattered, yellowish- 

 brown. Spores roundish or elliptical, echinulate, pale brown, 

 20-28 X 20-23/x., withotit paraphyses. 



Teleutospores — Sori very small, linear, numerous, covered by the 

 epidermis, black, scattered or in linear series. Spores oblong 

 or wedge-shaped, apex slightly thickened, generally truncate, 

 base attenuated, lower cell often paler, central constriction 

 slight, smooth, brown, 25-40 x 1 5-20/1,. Pedicels very short 

 or absent. 



Synonyms. 



Puccinia sessilis, Schneider. Schrdt., "Brandp.," p. 119. 

 Winter in Rabh., " Krypt. Flor.," vol. i. p. 222. 



Puccinia lijiearis, Rob. Cooke, " Micro. Fungi," 4th edit., 

 p. 203. 



yEcidium alia. Grev., "Flor. Fdin.," p. 447. Berk., " Eng. 

 Flor.," vol. V. p. 369. Cooke, " Hdbk.," p. 545 ; " Micro. 

 Fungi," 4th edit., p. 200. Johnst., "Flor. Berw.," vol. ii. p. 207. 



