Search on : Taxa descriptions

 


   
Literature:
 
Page number:52 
Remarks (internal):Stilbella aleuriata and Nectria macrostoma form a unique combination of anamorphs and teleomorphs that is unlikely to be mistaken for any other fungus when all three morphs are present. The extensively developed white to orange stroma with immersed perithecia, white to orange A-synnemata with lobed marginal hairs and dark B-synnemata with verrucose ornamenting cells make the fungus easily recognizable. The conidia of the A-synnemata vary in shape from collection to collection, usually being ellipsoidal but sometimes being almost cylindrical.
In my studies of a culture of N. macrostoma A-synnemata developed first, followed some weeks later by B-synnemata. Dingley (1957), studying cultures of N. macrostoma, reported growth of only B-synnemata on PDA.
More cultural studies are required before the relationship between the two anamorphs is properly understood. The A-synnemata are very similar to those of Stilbella albocitrina but S. albocitrina lacks a well-developed basal stroma. The B-synnemata are microscopically indistinguishable from the synnemata of Nectria gracilipes. Macroscopically, the B-synnemata are shinier and more greenish than those of S. clavulata but this is difficult to judge unless a number of collections can be compared. However, as the B-synnemata of N. macrostoma are always, in my experience, accompanied by the lighter A-synnemata, confusion of the two species should occur only rarely. All names considered synonyms of S. aleuriata above appear to have been based on the A-synnemata.
The extensive stroma develoµment of N. macrostoma is reminiscent of Hypocrea, which led Müller (in von Arx & Müller, 1962) to transfer N. macrostoma to the genus Hypocreopsis. Indeed, the stroma is conspicuous but all other features of the fungus fit Nectria well, and the stroma is just an extreme develoµment of prosenchyma, the same as that found, to a lesser degree, in Nectria gracilipes. N. macrostoma and N. gracilipes are very similar. They produce apparently identical B-anamorphs, have verruculose to echinulate ascospores, and have stromata composed of similar tissue types. Perithecia of both species are originally yellowish or orange, but become darkly pigmented with age.
Notes on synonyms: The Hypocrea-like stroma with nectrioid perithecia, combined with the synnematous anamorph led Patouillard to erect the genus Stilbocrea for this fungus. A number of other authors have added species to Stilbocrea over the years, all of which are here considered synonyms of N. macrostoma.
The earliest available name for the anamorph of N. macrostoma is Stilbum cinnabarinum Mont. (= Stilbella cinnabarina (Mont.) Wollenw.). According to Article 69, of the ICBN, a name should be rejected if it has been a long persistent source of error. This is certainly the case with Stilbum cinnabarinum, which has been the name used for the anamorph of Nectria pseudotrichia for at least a century. Using this name for the anamorph of N. macrostoma now would only lead to confusion and misinterpretation. A formal proposal to reject S. cinnabarinum shall be submitted to Taxon in the near future.
The type specimen of Sphaerostilbe hypocreoides Henn. has not been located. The diagnosis is consistent with N. macrostoma except for the dimensions given for the conidia. S. hypocreoides is considered a possible synonym of N. macrostoma here.
Nectria grisea was a new name introduced by Dingley (1951), because the epithets known to her at that time for this species were already occupied in Nectria
 
Description type:Non-original description 
Description:Nectria macrostoma Berk. & Curt. - Figs 12, 13.
Nectria macrostoma Berk. & Curt. - J. Linn. Soc., Bot. 10: 378. 1868 = Stilbocrea macrostoma (Berk. & Curt.) Höhnel - Sber. Akad. Wiss. Wien 118: 1185. 1909 = Hypocreopsis macrostoma (Berk. & Curt.) E. Müller apud von Arx & E. Müller Beitr. KryptogFlora Schweiz 2(2): 650. 1962.
Sphaerostilbe variabilis Berk. & Br. - J. Linn. Soc., Bot. 14: 115. 1875 = Nectria grisea Dingley - Trans. R. Soc. N. Z. 79: 180. 1951.
Sphaerostilbe hypocreoides Kalchbr. & Cooke - Grevillea 9: 26. 1880 (non S. hypocreoides Henn., 1902) = Stilbocrea hypocreoides (Kalchbr. & Cooke) Seaver - Mycologia 2: 62. 1910.
Stilbocrea dussii Pat. - Bull. Soc. mycol. Fr. 16: 186. 1900.
Sphaerostilbe hypocreoides Henn. - Hedwigia 41: 4. 1902 (non S. hypocreoides Kalchbr. & Cooke, 1880) = Sphaerostilbe henningsii Ferd. & Winge - Bot. Tidsskr. 29: 12. 1908 (name change).
Sphaerostilbe intermedia Ferd. & Winge - Bot. Tidsskr. 29: 12. 1908, fide Samuels & Dumont (1982) = Stilbocrea intermedia (Ferd. & Winge) Seaver - Mycologia 2: 63. 1910.
Sphaerostilbe placenta Theissen - Annls mycol. 9: 55. 191 I .
Stilbocrea jenkiana Viegas - Bragantia 4: 97. 1944, fide Samuels (pers. comm.).
Anamorph: Stilbella aleuriata (Berk. & Curtis) Seifert, comb. nov.
Stilbum cinnabarinum Mont. - Ann. Sci. nat., Bot., Ser. 2, 8: 360. 1837, nom. rej. prop. = Botryonipha cinnabarina (Mont.) O. Kuntze - Rev. Gen. Pl. 2: 845. 1891 = Stilbella cinnabarina (Mont.) Wollenw. - Angew. Bot. 8: 195. 1926.
Stilbum aleuriatum Berk. & Curt. - Grevillea 3: 63. 1874 (basionym) = Botryonipha aleuriata (Berk. & Curt.) O. Kuntze - Rev. Gen. Pl. 2: 845. 1891.
Stilbum connatum Kalchbr. & Cooke - Grevillea 9: 22. 1880 = Botryonipha connata (Kalchbr. & Cooke) O. Kuntze - Rev. Gen. PI. 2: 845. 1891.
Isaria aggregata Cooke & Massee - Grevillea 19: 48. 1890.
Stilbum corallinum Cooke & Massee - Grevillea 19: 91. 1891.
Stilbum subiculosum Pat. - Bull. trimest. Soc. mycol. Fr. 20: 138. 1904.
Stilbum intermedium Sacc. & Trott. - Syll. Fung. 22: 477. 1913, as anam. of Sphaerostilbe intermedia Ferd. & Winge.
Stilbum vanderystii Sacc. & Trott - Syll. Fung. 22: 477. 1913, as anam. of Sphaerostilbe henningsii Ferd. & Winge.
Stromata convex, round, elliptical or irregular in outline, at first white, becoming orange or pink and finally grey as perithecia mature, tending to become caramelized, smooth, punctate or pubescent, 1-15 mm long, 1-10 mm wide, 375-1250 µm thick, composed of a textura intricata of hyphae 3-5 µm wide. Perithecia up to several hundred caespitose, imbedded in stroma, ellipsoidal to ovoid, orange when young and visible as a papilla 50-75 µm wide protruding through surface of stroma, becoming red-brown to dark olive-green with age, and becoming exposed as stroma wears away, KOH-, 250-375 µm tall, 200-300 µm wide, undergoing cupulate collapse or lateral pinching when dry. Perithecial wall composed of a single region 10-30 µm thick, of compressed ellipsoidal to fusiform hyaline cells 5-17 x 2-3 µm, with walls slightly thickened but becoming less thickened towards locule; wall surrounded by a textura intricata of hyphae 2.5-3 µm wide; papilla about 70-90 µm wide, composed of a palisade of vertically oriented parallel hyphae 2.5-3 µm wide; ostiolar canal 60-100 µm long, lined with periphyses 1-1.5 µm wide. Asci cylindrical with an minute apical ring, 70-110 x 5-11 µm, 8-spored, uniseriate, basal 20-30 µm of ascus empty. Ascospores 1-septate, not constricted or slightly constricted at septum, ellipsoidal to slightly fusiform, verruculose to verrucose, (8.5-) 10-14 x 4-6 µm.
Synnemata of two types, here called A-synnemata and B-synnemata. A-synnemata solitary, gregarious, crowded or caespitose, arising from immature or mature teleomorph stroma, cylindrical-capitate, subulate-capitate, sometimes clavate, slender to robust, curved, nodding or straight, unbranched or sometimes with a single branch, in some specimens with up to 10 inequivalent branches near apex, smooth to granulose, at first white, becoming orange or orange-pink, 250-2000 µm tall, 50-225(-375) µm wide. Hyphae of stipe hyaline, parallel, 2-4(-8) µm wide, often with constricted septa; marginal hyphae covering entire stipe but usually concentrated towards apex, multilobed, with lobed aggregations up to 15 µm diam formed of individual lobes 1-2 x 1-1.5 µm, ornamented zone on hyphae 4-20 µm long.
Conidiophore branching once monochasial or monoverticillate, conidiophore 1.5-2 µm wide. Phialides cylindrical, subulate, straight or curved, lateral and terminal or in terminal whorls of 3-4, 10-25 µm long, 1-1.5 µm wide, periclinal thickening sometimes obvious. Conidial mass hemisphaerical, globose or ellipsoidal, orange, pink-orange, yellow-orange or red-brown, 75-350(-550) µm diam. Conidia oblong-ellipsoidal, cylindrical or obovate, 3-6(-1 3) x 1-2(-2.5) µm, usually with 1 or 2 polar guttules. B-synnemata solitary, gregarious to 3-4 caespitose, emerging from stroma, periphery of stroma, or several mm away from stroma, subulate-capitate, cylindrical-capitate, or clavate, grey. black or grey-brown, shiny, sometimes granulose in upper one half to one third, 1-2 mm tall, 50-200 µm wide. Microscopically identical to synnemata of Stilbella clavulata, described below under Nectria gracilipes.
Colonies on OA 26-28 mm diam after 14 days, plane, aerial mycelium lanose, white, in a low ring around inoculum, surface smooth, margin entire, reverse opaque white near centre, translucent white or cream-coloured near margin. A-synnemata forming in ring of aerial mycelium, often branched, microscopically as on natural substrate except marginal cells are poorly developed and basal stroma is absent; B-synnemata forming after 4-6 weeks, at periphery of colony, microscopically as on natural substrate. Mononematous conidiophores branching 2-3 level monochasial or twice monochasial, phialides lateral and terminal or in terminal whorls of 3-4, 30-37 x 1.5 µm, conidia ellipsoidal 5-6 x 1.5-2 µm.
Colonies on 2% MA 27-28 mm diam after 14 days, as on OA but inoculum may be covered with synnemata and light yellow conidial slime, reverse slightly mottled. Synnemata and mononematous conidiophores as on OA.
Cardinal temperatures: Minimum 12°C, optimum 24°C, maximum 30°C.
Effect of light: Not required for synnema formation. Conidial mass is less pink in darkness.
Habitat: Bark and decayed wood, recorded here from Acer negundo L. (Aceraceae), Citrus aurantium L. (Rutaceae), Daphnopsis caribaea Griseb. (Thymelaeaceae), Melicytus ramiflorus J.R. & G. Forst. (Violaceae), and Morus sp. (Moraceae), but host range is probably vast.
Distribution: Pantropical and subtropical, occasionally temperate. Recorded here from Africa (Gambia, Natal, Nigeria, South Africa, Uganda), SE Asia (Indonesia), S Pacific (Australia, New Zealand), North America (Florida, Louisiana, Texas), South America (Brazil, Guadeloupe). Reported by Samuels (1982) from West Indies (Bahamas, Cuba, Jamaica, Puerto Rico, St. Thomas, St. John, Trinidad) and Central America (Panama, Venezuela).
 
Taxon name: