140 



IM< i INI \ 



Spermogones. Chiefly epiphyllous, in little clusters, orange. 

 Uredospores. Sori generally hypophyllous, on yellowish or 



brownish spots (spots sometimes 

 aone), primary rather large, 

 secondary very minute, much 

 scattered, pulverulent, brown : 

 spores globose to ellipsoid, acu- 

 leolate, brown, 22—30 x 16 — 

 28 ix, with three (or two) germ- 

 pores. 



Teleutospores. Sori similar, but blackish-brown ; spores 

 ellipsoid or somewhat obovate, rounded at both ends, not thick- 

 ened above, not or hardly constricted, delicately verruculose, 

 chestnut-brown, 24—40x16 — 25 /*; epispore thin; pedicels 

 hyaline, thin, generally very short. 



Fig 



<)'2. P. . Centaureae. Teleuto- 

 spores and uredospore. 



On Centaurea nigra. Teleutospores, August- 

 Common. (Fig. 92.) 



November. 



As Plowright says, there are two generations of uredospores. The 

 primary uredospores, which are the equivalent of the secidiospores, accom- 

 panied by spermogones, appear in May, and are followed by the secondaiy 

 uredospores, which form much smaller sori. The former, however, do not 

 occur on every infested plant, being only produced from direct infection 

 by the basidiospores. The primary uredospores are widely scattered by 

 the wind ; Plowright proved that they produce the secondary spores in 

 about fourteen days. Fischer and Jacky record this also on ('. Scabiosa, 

 but the Puccinise on other species of Centaurea arc considered to be 

 distinct species or else biological races. 



Distribution: Europe. Asia Minor, Siberia, North America. 



14. Puccinia Cyani Pass. 



Uredo Cyani Schleich. Plant. Helv. 95. 



Puccinia suaveolens var. Cyani Winter, Pike Deutschl. p. 190. Plowr. 



Ured. p. 183. Sacc. Syll. vii. 633. 

 P. Cyani Pass, in Rab. Fung. Eur. 1767. Sydow, Monogr. i. 38. 



Spermogones. A few mixed with the primary uredo-sori. 

 Uredospores. Sori generally hypophyllous, without spots, 

 scattered or crowded, minute, roundish, pulverulent, cinnamon: 



