. The British rust fungi (Uredinales), their biology and classification. Uredineae. 256 PUCCIXIA with three or four inconspicuous germ-pores; paraphyses very few or wanting. TeleiUospores. Sori hypophyllous, sometimes arranged in circles round the uredo-sori, rarely scattered, occasionally con-. Fig. 195. P. Lolii. jEcidia on leaves of li. catharticns ; Teleutospores, a, on Lolium, b, on Arrhenatherum. fluent, oblong or linear, ^—1 mm. long, nearly always covered by the epidermis, black; spores as in P. coronata, but very irregular; mesospores also occur. ^cidia on Rhamnus catharticns, May and
. The British rust fungi (Uredinales), their biology and classification. Uredineae. 256 PUCCIXIA with three or four inconspicuous germ-pores; paraphyses very few or wanting. TeleiUospores. Sori hypophyllous, sometimes arranged in circles round the uredo-sori, rarely scattered, occasionally con-. Fig. 195. P. Lolii. jEcidia on leaves of li. catharticns ; Teleutospores, a, on Lolium, b, on Arrhenatherum. fluent, oblong or linear, ^—1 mm. long, nearly always covered by the epidermis, black; spores as in P. coronata, but very irregular; mesospores also occur. ^cidia on Rhamnus catharticns, May and June; uredo- and teleutospores on Alopecurus pratoisis, Arrhenatherum elatius, Avena fataa, A. pratensis, A. sativa, Festuca elatior, Glyceria aquatica, Holciis 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 Holcus, and also on cultivated Oat which alone of the cereals it attacks, doing considerable damage. The teleutospores can be found on xirrhenatherum 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 Avenue is the most important; see p. 68. It is found in Australia on Oat and Rye-grass (introduced with seed ?) although no species of Rhamnus is indigenous there (McAlpine). DiSTRiBUTiOX: Europe, Asia, North America, Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - col
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