256 PUCCINIA 
with three or four inconspicuous germ-pores; paraphyses very 
few or wanting. 
Teleutospores. Sori hypophyllous, sometimes arranged in 
circles round the uredo-sori, rarely scattered, occasionally con- 
Fig. 195. P. Lolii. Acidia on leaves of R. catharticus ; Teleutospores, 
a, on Lolium, b, on drrhenatherum. 
fluent, oblong or linear, 3—1 mm. long, nearly always covered 
by the epidermis, black; spores as in P. coronata, but very 
irregular; mesospores also occur. 
AKcidia on Rhamnus catharticus, May and June; uredo- and 
teleutospores on Alopecurus pratensis, Arrhenatherum elatius, 
Avena fatua, A. pratensis, A. sativa, Festuca elatior, Glyceria 
aquatica, Holcus lanatus, H. mollis, Lolium perenne; not yet 
recorded on all these species of grass in Britain. (Fig. 195.) 
The Crown Rust of the Oat is most commonly found on Rye-grass, 
frequently also on Arrhenatherum and Holecus, and also on cultivated 
Oat which alone of the cereals it attacks, doing considerable damage. 
The teleutospores can be found on .lrrhenatherum from the middle of 
August onwards and, as Plowright remarked, are “accompanied by a 
profuse development of uredospores”—so profuse, indeed, as to attract 
the notice of even non-botanical eyes. The uredo-sori form more blister- 
like swellings and the teleuto-sori remain longer covered by the epidermis 
than is the case in P. coronata. The uredospores are much brighter in 
colour than those of P. graminis. 
This species has been divided by Eriksson into a varying number of 
biological races, of which P. Lolii .lvenae is the most important; see p. 68. 
It is found in Australia on Oat and Rye-grass (introduced with seed 2) 
although no species of RAamnus is indigenous there (McAlpine). 
DisTRIBUTION: Europe, Asia, North America, Australia. 
