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Page number:89 
Description type:Culture description 
Description:DICHOSTEREUM EFFUSCATUM (Cooke & Ellis) Boidin & Lanquetin
Mats white, around inocula moderately thin, slightly raised, subfelty to downy, then becoming moderately thick, raised, cottony-woolly toward margins at 2 wk, by 6 wk white to Capucine Buff or Apricot Buff, moderately thin to moderately thick, appressed to slightly raised, subtomentose to felty, rarely tomentose, fertile areas Light Salmon-Orange, smooth, coalescing; margins even, appressed to slightly raised; no odor at 2 and 6 wk; agar unchanged at 2 wk, Orange-Buff to Mars Orange by 6 wk; fresh isolates fruiting by 3 wk. MEA 52-72; (70-)90+; GAA ++++, 0-tr; TAA ++++, 15-37; (24-)40-72; TyA -, 27-48; - or yellow, 80-90+
Microscopic characters: Marginal hyphae 3-4.5 µm diam, thin walled, nodose septate, sparsely branched, usually branches arising usually opposite clamps. Submerged and aerial hyphae 1.5-4 µm diam, thin walled, nodose septate, moderately branched, with segments heavily encrusted with hyaline crystals. Gloeoplerous hyphae (Fig. 24a) 2-3 µm diam, thin walled, aseptate, rigid, with branches diverging at right angles, filled with refractive materials, scattered in submerged mats at 2 and 6 wk. Gloeocystidia hemispherical to cylindrical, 2-8 µm diam, often apically papillate, lateral or terminal, containing refractive, oil-like globules, abundant in aerial mats at 2 and 6 wk. Chlamydospores ovoid to globose, 11-16 x 9-13 µm, thin walled to thick walled terminal or intercalary, abundant in aerial and submerged mats at 2 and 6 wk. Conidia lacrymoid to globose, 3-4 x 2-2.5 µm, thin walled, blastic, borne on oedocephaloid conidiophores (Fig. 24b), these at least 50 x 6-8(-9) µm, often swollen at base, with numerous sterigmatoids, abundant in aerial mats at 2 and 3 wk but absent by 6 wk.
Sexuality: Tetrapolar (Nobles 1942, p. 349).
Cultural descriptions: Boidin (1958a, p. 217); Lanquetin (1973b, p. 176); Lentz & McKay (1966, p. 15); Lyman (1907, p. 176); Nobles (1942, p. 350); Stalpers (1978, p. 109).
Species codes: 2. 3c. 15p. 33. 34. 36. 39. 42-43. (48).54. 60. 2. 3c. 8v. 15. 33. 34. 36. (39). 43. 48.54. 60. 63. (Lanquetin 1973b, p. 178, except 25d changed to 8v).
Remarks: Dichostereum effuscatum is associated with a white rot (Gilbertson & Lombard 1976; Ginns 1986a) of woody angiosperms throughout the eastern half of North America (Burt 1926; Gilbertson 1965b; Conners 1967; Ginns 1986a). It is common in wet, swampy places. Lanquetin (1973b) reported the development of dichohyphidia in cultures grown on Hagem agar. The species of Dichostereum described herein are difficult to distinguish in culture (Table 4). All four species produce gloeoplerous hyphae in culture which are not typical but are called that for lack of a better descriptive term. These gloeoplerous hyphae are narrow, rigid, aseptate and with branches diverging at right angles and may represent a developmental stage in the formation of dichohyphidia.
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