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Page number:252 
Remarks (internal):E. cichoracearum parasitizes a wide range of host species. This species is confined to hosts of the Asteraceae. It is a complicated complex of numerous races. Only some extreme "forms" are morphologically clearly distinguished and could be separated as varieties. There is a closely related species with a wide host range. This species is able to infect numerous unrelated host species. HammerIund (l.c.) called this species "E. polyphaga." He separated this species from E. cichoracearum mainly on account of his biological investigations. But there are, indeed, obvious morphologicaI differences. Hammett (l.c.) established two "entities" of E. cichoracearum (4 - E. cichoracearum s.str. on Asteraceae; 5 - E. cichoracearum on various hosts, e. g. Aster, Cardamine, Cucurbitaceae, Nicotina, Petunia, Solanum, Viola, Valerianella, Veronica). He pointed out some differences between the two entities (spore units swollen in entity 4, unswollen in 5). Entity 5 corresponds to "E. polyphaga." Braun (1980) found clear differences between the anamorphs of E. cichoracearum s.str. and some polyphagous races (on Aster, Solidago, Chrysanthemum spec. cult., Viola, Antirrhinum, Papaver, Camelina, Capsella, Neslia). The foot-cells of the conidiophores are often curved at the base. The anamorphs of these races resemble the Oidium of E. cynoglossi. Gorter & Eicker (1983) came to similar conclusions and treated a sample on Papaver under E. cynoglossi. This fungus was transmissible to tobacco, cucumber and Viola. Boesewinkel (1979) described an anamorph on Veronica arvensis under E. asperifoliorum.
The present fungus is well characterized by its polyphagous nature and by some differences in the anamorphic state. The ascocarps are very rarely formed. The asci are 2-4-spored. E. cichoracearum s .str. should be confined to hosts of the Asteraceae and the polyphagous races should be considered as a separate species. E. orontii is the oldest available name. Antirrhinum is a common host of "E. polyphaga." The conidial state is widespread on A. majus and A. orontium. E. orontii is composed of various races with different host ranges. The "biological structure" of this species is very complex. The following authors proved the polyphagous nature of this species: Reed (1907, 1908), Hammarlund (1945), Blumer (1952), Schmitt (1955), Stone (1962), Gorter & Eicker (1983).
 
Description type:Non-original description 
Description:Erysiphe orontii Cast. , Suppl. Cat. Pl. Mars., p. 52 (1851) emend. U. Braun
Syn.: E. tabaci Sawada, Bull. Dept. Agr. Govt. Res. Inst. Formosa 24, p. 23 (1927), type host - Papaver somniferum, Iectotype, Sawada, l.c., pl. I, fig. 6-9. E. polyphaga Hammarlund, Bot. Not. 1945, p. 108 (1945), nom. nud. E. cucurbitacearum Zheng & Chen, Sydowia 34, p. 258 (1981), type host - Cucumis sativus. E. cichoracearum auct. p. p.
Anamorph: Oidium violae Pass., in Thüm., Myc. univ., cent. XII, No. 1176, Klosterneuburg 1878. O. begoniae Puttem., Bull. Soc. R. Bot. Belg. 48, p. 238 (1911). O. lini Skor., Glansn. Sum. Pok. 1, p. 106 (1926).
Ill.: Sawada (l.c., pl. I, fig. 6-9). Hammett (1977, p. 699, fig. 8 A, B, D-G). Braun (1980, p. 78, fig. 1 b). Zheng & Chen (1981b, p. 259, fig. 20). Gorter & Eicker (1983, p. 39, fig. 4-6).
Lit.: Junell (1967, p. 41). Hammett (1977,p. 698-699). Boesewinkel (1979, p. 29). Braun (1980, p. 78-79, sub E. cichoracearum). Gorter & Eicker (1983, p. 39, sub E. cynoglossi).
Mycelium amphigenous, effused or patches, evanescent or persistent, white, hyphae slightly flexuous, branched, at right angles, ca 5-7 µm wide, appressoria nipple-shaped, often poorly developed, conidiophores erect, simple, foot-cells straight or often curved in the basal half, ca 40-100 x 10-13 µm, followed by 1-3 shorter cells (ca 10-25 x 11-14 µm), sometimes cells longer, conidia in chains, chains usually not very long, spore units unswollen, ellipsoid-ovoid to doliform-subcylindric, ca 25-40 x 15-23 µm (fresh), l/w ratio usually somewhat below 2, germ tubes arising from an end, occasionally from a side, usually fairly short, about as long as the conidium or shorter, frequently somewhat twisted, broadened, sometimes straight, bent or helicoid, rarely forked, apically often somewhat swollen. Cleistothecia largely agreeing with those of E. cichoracearum, ca 80-140 µm in diam, cells irregularly shaped, ca 8-20 µm diam, appendages numerous, in the lower half of the ascocarp, mycelioid, generally simple, rarely irregularly branched, 0.5-2 times as long as the cleistothecial diam, width irregular, (3-)5-7.5(-10) µm, thin-walled, smooth to rough, septate, coloured, brown, paler upwards, appendages interlaced with each other and with the mycelium, asci 5-14, stalked, 45-75 x 25-40 µm, 2(-4)-spored, spores ellipsoid-ovoid, hyaline or yellowish, ca 16-25x 12-15(-17) µm.
Holotypus: on Antirrhinum orontium L., France, herb. Castagne (PC).
Hosts and distr.: on numerous host species of various host families, Acanthaceae (Acanthus, Thunbergia), Apocynaceae (Apocynum, Vinca), Asclepiadaceae (Asclepias), Asteraceae (Aster, Chrysanthemum, Dahlia, Helianthus, Solidago), Begoniaceae (Begonia), Bignoniaceae (Incarvillea), Brassicaceae (Brassica, Camelina, Capsella, Cardamine, Erysimum, Eruca, Neslia, Raphanus), ? Campanulaceae (Campanula, Specularia), ? Cistaceae (Helianthemum), Crassulaceae (Aeonium, Bryophyllum, Cotyledon, Echeveria, Kalanchoe, Rochea, Sedum, Sempervivella, Sempervivum), Cucurbitaceae (Benincasa, Bryonia, Bryoniopsis, Cephalandra, Citrullus, Coccinea, Cucumis, Cucurbita, Cyclanthera, Ecballium, Echinocystis, Lagenaria, Luffa, Melothria, Momordica, Sechium, Sicyos, Thladiantha, Trichosanthes), Ericaceae (Calluna, Erica), Euphorbiaceae (Ricinus), Gesneriaceae (Achimenes, Saintpaulia, Sinningia, Streptocarpus), Hydrangeaceae (Hydrangea), Lamiaceae (Galeobdolon, Hyssopus), Linaceae (Linum), Malvaceae (Abelmoschus, Althaea, Hibiscus), Myrthaceae (Eucalyptus), Oxalidaceae (Oxalis), Papaveraceae (Papaver), Pedaliaceae (Sesamum), Primulaceae (Cyclamen), Scrophulariaceae (Antirrhinum, Chelone, Digitalis, Hebe, Linaria, Melampyrum, Pentslemon, Scrophularia, Veronica), Solanaceae (Cestrum, Datura, Lycopersicum, Nicotina, Petunia, Physaliastrum, Physalis, Physochlaena, Salpiglossis, Schizanthus, Scopolia, Solanum), Urticaceae (Forsskalea, Urtica), Valerianaceae (Valerianella), Verbenaceae (Verbena), Violaceae (Viola), Vitaceae (Cissus), circumglobal.
 
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