2-")4- PUCCINI A 



scattered or arranged in rows, rarely confluent, minute, more 

 or less oblong, pulverulent, orange; spores globose to ovate, 

 shortly eehinulate, yellow, 10 — 2o x 14 — '20 /x, with three or 

 four germ-pores (about ten, Fischer, but ?), and mingled with 

 a tew paraphyses. 



Teleutospores. Sori hypophyllous, irregularly scattered. 

 rarely confluent, oblong or linear, covered by the epidermis, 



s naked, black; spores cuneate, flat at the summit and 



crowned with about 5 — 7 obtuse (digital iform) darker-coloured 

 teeth, hardly or not at all constricted, gradually tapering 

 towards the base, smooth, brown, 35 — 60 x 12 — 22 li; pedicels 

 short, rather thick. 



/Ecidia on Rhamnus Frangula, May and June; uredo- and 

 teleutospores on Agropyron repens, Agrostis alba, A. stolonifera , 

 A. vulgaris, Calamagrostis lanceolata, Dactylis glomerata, 

 Festuca sylvatica, Holcus lanatus, H. mollis, PJudaris arun- 

 dinacea (but not yet recorded on all these grasses in Britain), 

 August — October. Common. 



On account of the processes at the summit of the teleutospore this 

 species is called Crown Bust. It was surmised by Plowright that there 

 are two Crown Rusts; these have since been called P. coronata and 

 /'. Lolii ( = P. coronifera). They are equally widely distributed, but are 

 said to occur on different grasses, with the exception that they are both 

 found on the two species of Holcus. 



In accordance with custom, they are here kei>t separate, but aside 

 from the distinction of the hosts they can be separated only by minute 

 differences. When they occur on Holcus, therefore, the only test that 

 could absolutely decide the matter would be to await the maturation of 

 the teleutospores, and then try if they would infect R. Frangula. The 

 lighter-orange colour of the uredo-pustules, and t lie character of the germ- 

 pores will, however, distinguish either of them from P. graminis, when 

 occurring on the same hosts ; in the Crown Rusts, moreover, both kinds 

 of sori are confined almost entirely to the leaves. 



The teleuto-sori of P. coronata have a less decided tendency to group 

 themselves round the uredo-sori than in P. Lolii, and do not remain so 

 long covered by the epidermis, becoming naked early in the autumn. In 

 the ufedo-sori, Eriksson says that paraphyses occur in P. coronata and 

 hardly at all in P. Lolii ; but the evidence seems to favour the conclusion, 

 in generd, that the presence or absence of paraphyses is a note of little 

 importance. Plowright mentions an interesting fact, confirmed by Pole- 

 Evans, that the Crown Rust, when it occurs on Dactylis, is an early summer 



