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Remarks (public):For a complete description including images see 
Remarks (internal):This disease is widespread on the leaves and sometimes the inflorescence bracts of carnations. It appears in the late autumn during and after damp periods. The extent of an outbreak depends on climatic conditions.
Description type:Non-original description 
Description:Cladosporium echinulatum (Berk.) G.A. de Vries, Contribution to the knowledge of the genus Cladosporium Link ex Fr., p. 49, Baarn, 1952.
Helminthosporium echinulatum Berk., 1870.
Heterosporium echinulatum (Berk.) Cooke, 1877.
Helminthosporium exasperatum Berk. & Broome, 1873.
Heterosporium dianthi Sacc. & Roum., 1881.
Teleomorph: Mycosphaerella dianthi (Burt) JÀ¸rst., Melding fra Statens Plantepatologiske Institut 1: 17, 1945.
Leaf lesions grey to fawn, with a dark grey-brown margin, at first circular-elliptic spots 1-2 mm diam., later becoming confluent. Mycelium abundant, composed of immersed colourless to olivaceous brown, branched, septate hyphae, 3-12 µm wide, with rather unevenly thickened walls; with aerial hyphae only present in cultures. Stroma black, pseudoparenchymatouson the host, prosenchymatous in culture. Conidiophores arising on the host through stomata, often in dense fascicles, unbranched or occasionally branched, septate, sometimes swollen at the base, flexuous, often geniculate, pale- to mid-brown, smooth, up to 200 x 8-13 µm. Conidiogenous cells terminal, becoming intercalary, with conidiogenous loci sympodially arranged. Conidia solitary or in unbranched or branched chains, cylindrical, sometimes narrowing towards the base, obtuse at both ends, (1-) 2-4 (-6)-septate, usually not constricted at the septa, coarsely echinulate or verrucose, mostly pale-brown sometimes becoming dark, (15-) 25-55 (-62) x 8-17 µm. Conidial development initiation holoblastic from sympodially proliferating conidiogenous cells, usually solitary or in short unbranched acropetal chains; secession schizolytic, leaving a thickened, pigmented scar, which is not usually protuberant. Ascomata black, globose, up to 270 µm diam., with beaks 10-30 µm high, and with a pseudoparenchymatous ascomatal wall,usually composed of 5-8 layers of cells. Paraphyses absent. Asci in fascicles (8-18 per ascoma), saccate, obpyriform to subcylindrical, 'fissitunicate', each with 8 ascospores more or less irregularly arranged. Ascospores ovate-elliptic, slightly constricted at the septum, 20-30 x 7-9 µm, with a shorter wide upper cell and a longer narrow lower cell.
Hosts: Dianthus spp., occasionally also on other similar members of the Caryophyllaceae, such as Lychnis and Saponaria.Disease: Leaf spot of carnation.Geographical distribution: Africa: Kenya, Morocco, South Africa, Uganda. Asia: Cyprus, India, Iran, Japan Turkey. Australasia: New Zealand. Europe: Austria, Belgium, Bulgaria, Czechoslovakia, England, Finland, Italy, Iceland, Norway, Romania, Spain, Sweden, Switzerland, West Germany, Yugoslavia. North America: Canada (British Columbia), El Salvador, Mexico, USA (California, Florida, Massachusetts, New York, Oregon, Texas). South America: Argentina, Brazil, Chile, Columbia, Peru.
Physiological specialization: None reported.Transmission: Conidia are dispersed by wind or rain, spreading from leaf to leaf, or to new plants.
Literature: Burt, Transactions of the British Mycological Society 20: 207-215, 1936; Dowson, Mycologisches Centralblatt 2: 1-14, 78-88, 136-143, 1913.

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