Micropiiccinia. 209 



Puccinia senecionis. Lib. 



Teleutospores — Sori small, crowded, chestnut-brown, at first hemi- 

 spherical, then depressed in the centre, becoming perforate, 

 at length pulverulent. Spores irregular in form, subovoid 

 or elliptical, lower cell sometimes attenuated, upper gene- 

 rally rounded, but often pointed, brown, smooth or granular, 

 40-50 X i8-28ju,. Pedicels short, hyaline, deciduous. 



Syno7iym. 



Puccinia senecionis, Lib. Cooke, " Micro. Fungi," 4th edit, 

 p. 207. 



Exsiccati. 

 Cooke, i. 37 ; ii. 236. Vize, "Fungi Brit.," 21. 



On Senecio aquaticus. 

 September. 



Biology. — The mycelium has a great tendency to follow the 

 venation. The sori are enclosed in an indistinct pseudoperidium, which 

 remains as a honeycomb-like matrix in the centre of the sori-clusters 

 after the spores have fallen off. The sori are brown, not black as in 

 P. glomerata. 



Puccinia .glomerata. Grev. 



Teleutosp07-es — Sori small, black, circinating, crowded, soon pul- 

 verulent, in roundish or elongated clusters. Spores elliptical, 

 elongated, or irregular, lower cell often smaller, constriction 

 slight, upper cell rounded or attenuated, usually surmounted 

 by a colourless papilla, smooth or granular when old, dark 

 brown, 30-40 X 20-25^. 



Synonym. 

 Puccinia glomerata. Grev., " Flor. Edin." Berk., " Eng. 

 Flor.," vol. V. p. 365. Cooke, " Hdbk.," p. 500 ; " Micro. Fungi," 

 4th edit., p. 206. 



Exsiccati. 

 Berk., 220. 



On Senecio Jacobcea. 

 August to November. 



