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Remarks (public):For a complete description including images see www.cababstractsplus.org/dfb 
Remarks (internal):Apparently this rust occurs only on Rubus corylifolius (34: 380) in Norway.
 
Description type:Non-original description 
Description:Phragmidium bulbosum (Strauss) Schlecht., Fl. Berol. 2: 156, 1824.
= Uredo bulbosa Strauss, Annln Wetter. Ces. 2: 108, 1810.
= Phragmidium rubi (Pers.) Winter, 1882.
Autoecious; macrocyclic. Pycnia epiphyllous, in minute groups opposite the aecia, indefinite, becoming fused, subcuticular, c.25-30 µm high. Aecia hypophyllous, caeomoid, circular or annulate, up to 1 mm diam., orange, paraphysate. Aeciosporesglobose to broadly ellipsoid, 17-21 µm diam.; wall hyaline, coarsely verrucose with broad shallow warts up to 3 µm diam.,1,5-2 µm thick; pores obscure. Uredia hypophyllous, irregularly scattered without spots or on small reddish, yellowish, brownish, or purplish spots or occasionally on larger purplish blotches, 0,1-0,3 mm diam., yellowish, paraphysate. Urediospores obovoid to ellipsoid, 19-24 x 16-18 µm; wall hyaline, echinulate, the spines 1-2 µm apart, c. 0,5 µm high, 1-2 µm thick; pores 2,5-4 µm diam., rather obscure; paraphyses cylindric-clavate, incurved, 40-60 x 8-13 µm, wall thickened to 2-3 µm at the apex. Telia like the uredia but black. Teliospores cylindric, not constricted at the septa, apex rounded and with a blunt apiculus up to 13 (-19) long and 5-7 µm wide, 4-7-celled, dimensions excluding the apiculus: 4-celled spores (59-)65-68 (-71) x (30-) 32-35 (-37) µm, 5-celled spores (73-) 78-83 (-89) x (32-) 35 (-37) µm, 6-celled spores (86-) 91-98 (-104) x (32-) 34-35 (-37) µm, 7-celled spores (98-) 104 (-111) x (32-) 33-34 (-36) µm; wall sienna to dark umber brown,coarsely warted, 4-5 µm thick; pores 2-4 in each cell; pedicels 75-160 long, 7-10 µm wide at the neck, swollen below to 13-19 µm wide.
Hosts: On Rubus fruticosus sect. Corylifolii (European blackberry) and on R. caesius (dewberry).
Disease: Blackberry leaf rust.
Geographical distribution: Widely recorded in Western Europe (Denmark, Finland, France, Germany, Great
Britain, Ireland, Norway, Sweden, Spain).
Physiological specialization: Not known.
Transmission: Presumably by windblown and perhaps splash-borne spores.
Literature: Klebahn, Z. PflKrankh. 17: 139, 1907; Klebahn, Z. PflKrankh. 22: 321-350, 1912 (host susceptibility); Wilson & Henderson, British rust fungi, 1966.

 
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