Search on : Taxa descriptions


Page number:107 
Remarks (internal):The germ tubes of the conidia arise from a side. They are narrow, ca 4-5 µm wide, simple, short or long. 
Description type:Non-original description 
Description:Sphaerotheca pannosa (Wallr. : Fr.) Lév., Ann. Sci. Nat., bot., 3 sér., 15, p. 138 (1851)
Syn.: Alphitomorpha pannosa Wallr., Verh. Ges. naturf. Fr. Berlin 1,p. 43 (1819). A. rosae Wallr., Ann. Wetter. Ges. N. F. 4, p. 238 (1819), type host-Rosa cinnamomea. Erysiphe pannosa (Wallr.) Fr., Syst. myc. 3, p. 236 (1829). Eurotium rosarum Grev., Scot. Crypt. Fl. III, p. 164, fig. 2 (1823). Podosphaera pannosa (Wallr. : Fr.) de Bary, Abh. Senkenb. naturf. Ges. 7, p. 48 (1870). Albigo pannosa (Wallr. : Fr.) Kuntze, Rev. Gen. Pl. III, p. 442 (1892). S. pannosa var. persicae Woronich., Trud. prikl. Bot. VII (7), p. 749 (1914). S. pannosa var. rosae Woronich. (1.c.). S. macularis f. rosae Jaczewski (1927, p. 76). S. persicae (Woronich.) Erikss., Die Pilzkr. d. Garten- u. Parkgew., p. 239, Stuttgart 1928. S. rosae (Jacz.) Zhao, Acta Microbiol. Sinica 21(4), p. 439 (1981).
Anamorph: Oidium leucoconium Desm., Ann. Sci. Nat., sér. 1,13, p. 102 (1829).
On leaves, sepals, fruits and stems, primary mycelium white, hyphae thin, 3-7 µm diam, conidiophores erect, foot-cells straight, nearly cylindric, ca 45-80 x 7.5-12 µm, followed by 1-2 shorter cells, conidia in chains, ellipsoid-ovoid to doliform, 20-33 x 12-19 µm, appressoria ± nipple-shaped, the persistent secondary mycelium is dense and pannose, patches, sometimes effused, forming a white to greyish, sometimes greyish brown felt, consisting of rather coarse, sparsely branched, thick-walled hyphae, ca 4.5-8 µm wide, infected shoots often disfigured and distorted, infections on leaves usually less conspicuous, often without deformations, but also persistent or, at least, subpersistent with some persistent thick-walled hyphae. Cleistothecia immersed in the mycelial layer, mostly ± gregarious, 70-115 µm in diam, rarely somewhat larger, cells irregularly polygonal to rounded, ca 8-25 µm diam, appendages in the lower half, usually not very numerous, mycelium-like, often characteristically undulate-contorted, often very short, shorter than the cleistothecial diam, sometimes rudimentary, or appendages longer, 0.5-2 times the cleistothecial diam, rarely exceeding, simple, interlaced, 38 µm wide, septate, smooth to faintly rough, thin-walled or sometimes moderately thick, hyaline, later coloured, yellowish to brown below, paler upwards, ascus 70100 x 50-80 µm, (4-) 8-spored, ellipsoid-ovoid (-doliform), 16-28 (-31) x 9-18 µm. Pl. 11, fig. A.
Typus; on Rosa villosa L., Wallroth (STR ?), not seen.
Hosts and distr.: on various host species of Rosa and Prunus (amygdalus, armeniaca, laurocerasus, melanocarpa, mume, nigra, persica), circumglobal.
Taxon name: