•220 PUCCINIA 



specimens is examined. The spores are, however, variable in form and 

 colour, and the sori differ in appearance and arrangement ; no doubt the 

 future will timl this Puccinia divided into several biological races, if not 

 into distinct species. Meanwhile, on morphological grounds alone, our 

 British forms may be arranged under three beads: 



1. forma Lychnidearum 'Link), on Lychnis; sori medium-brown in 

 colour, often greyish, remarkably circinate, on conspicuous yellow 

 and purple spots. 



2. forma Dianthi (DC), on Diantkus; sori larger, darker, and more 



pulvinate, usually somewhat circinate; =P. DianthiDC. 



3. forma Arenariae (Schurn.), on Armaria and Stellaria ; sori paler, 

 not so circinate. spores paler ; =/'. Moehringiae Fckl. 



The form on Sagina procumbens is so different that it is here reckoned 

 as a separate species. /'. Saginae K. et S. (q.v.). It will be noticed that 

 Plowright separated P. L;i<-hnido<ii'v:it\ as a distinct species from /'. 

 Arenariae, chiefly on the ground that he considered the former to possess 

 uredospores. It has been observed by all. however, that the common 

 form on Litr/mi* diurnu lias no uredospores in its very abundant sori ; it 

 is therefore satisfactory to find that in Plowright's herbarium there are 

 several leaves of Lyrhui* din ma, gathered by W. Phillips at Aberystwyth 

 apparently on one occasion only July 1873), on which are uredospores 

 mixed with very few teleutospores. These he named P. Lyclinid<-arn,,i, 

 but examination shows that they have no connection with the common 

 fungus met with everywhere on the same host but belong to P. Behenis 

 Otth. See under that species. 



The Puccinia recorded by Plowright {I.e. p. 210) on Spergida arvensis 

 may he a distinct species. See Cooke, Micr. Fung. p. 210. I have seen 

 no specimens. 



When mature, the cells of the teleutospores of P. Ly/,, 'Id, .,,•„,„ 

 separate with great ease; they germinate readily while still in the sori, 

 and the numerous basidiospores produced give them a greyish look, as 

 happens also in other Lepto- species. I have specimens on Arenaria 

 trinervis gathered in full germination at the end of May. During the 

 process the spores become denticulate at the summit ; in the ease 

 mentioned 7"> of the spores were in this state. Such spores have some- 

 times been wrongly described as having digitate processes like those of 

 /'. coronata. — It was stated by De Bary that he had seen the germ-tubes 

 of the basidiospores of P. Dianthi enter the host-plant through the 

 stomata : no similar case has been detected by any other observer (see 

 p. 38). 



Distribution : Europe, Siberia, East Indies, North and 

 Smith America. 



