134 



Puccini a Cyperaceae. 



Magnus first experimentally proved, in 1872, that Aecidium urticae 

 DC., was genetically connected with Puccinia caricis occuring on Car ex hirta. 

 Dr ' Plowright also, in many cultures, has shown that the aecidiospores pro- 

 duce the uredospores on species of Carex, and the teleutospores produce the 

 aecidiospores on Urtica. 



On the under surface of the leaves the aecidia occur in small groups, but 

 on the leaf-stalks and stems they are in large, bright-orange patches, 

 thickening and distorting the parts on which they occur. 



Magnus 1 has also shown that this rust winters on Carex hirta by 

 means of the uredo-generation. 



(Plate IV., Figs. 29, 30.) 



Cyperus. 

 56. Puccinia cyperi Arthur. 



Arthur, Bot. Gaz., p. 226 (1891). 

 Sydow, Mon. Ured. L, p. 681 (1903). 

 Sacc. Syll. XL, p. 199 (1895). 



II. Uredosori hypophyllous, on brown effused spots, scattered irregu- 



larly or aggregated, ellipsoid to oblong, variable in size, 1-2 mm. 

 long, long covered by the thick epidermis, ochraceous or brownish. 

 Uredospores yellowish-brown, ellipsoid, echinulate, 22-25 x 

 19-21 ju. 



III. Teleutosori hypophyllous, on similar spots, 1-3 mm. long, almost 

 always covered by the epidermis, blackish brown. 



Teleutospores intermixed with uredospores, elongated oblong to 

 elongated fusiform, brown and paler beneath, smooth, constricted 

 or hardly constricted at septum, 35-57 X 15-20 p, average 48 X 

 15 fj. ; upper cell rounded or often obtusely and obliquely acuminate 

 at apex, and thickened (up to 13 p) ; lower cell paler, oblong, but 

 usually attenuated towards base ; pedicel coloured like lower cell, 

 persistent, 20-30 ^ long, but may reach a length of 40 p. 



X. Mesospores generally paler in colour than the teleutospores, ellip- 

 soid to fusiform or even curved, obtusely and sometimes obliquely 

 pointed at apex, thickened (up to 5 p), 30-32 X 13-17 /t ; pedicels 

 similarly coloured, persistent, up to 22 f.i long. 



On leaves of Nut grass (Cyperus rotundus L.). 



Queensland Gatton, Aug., 1903 (Shelton) (Bailey, 18 , 20 ). 



The teleutospores are very variable in shape, and sometimes the cells 

 may be placed almost at right angles to each other. They are sometimes 

 excessively elongated, and may reach a length of 67 p. 



Intermixed with the teleutospores there are numerous stalked bodies 

 similarly coloured, and representing what are usually called mesospores, 

 although Sydow describes them as paraphyses. While mesospores generally 

 have an undoubted resemblance to the teleutospores with which they are 

 associated, their function in this case steems to be that of paraphyses, and 

 it may be in some other cases as well. 



Darluca filnm Cast., was common on uredosori. 



(Plate IV., Fig. 32.) 



