Type: Sooty Moulds and Similar Fungi; Description: Subiculum superficial, black, thin; on branches. Mycelium composed of pale brown to brown, smooth hyphae up to 15 μm wide. Ascomata perithecial, dark brown to black, subglobose, usually with a short stalk, 0.1 mm in diameter, ostiolate. Asci clavate. Ascospores obovoid, transversely 3–5-septate with longitudinal septa in all, or all but the terminal cells, 18–25 × 9–11 μm, smooth, pale brown to brown. Conidiomata pycnidial, more or less cylindrical, simple or up to six conidiomata may be borne on a branched, robust black stalk which is up to 250 μm long, black below and brown above, ostiole fringed with hyaline hyphae. Conidia oblong to ellipsoidal, 1-septate, 7–9 × 3–4 μm, smooth, pale brown to brown.

Distribution: Auckland.; 1st Record: Hughes (1981a).

Significance: None.; Host(s): Schefflera digitata.

On corticated twigs of Schefflera digitata, Auckland Prov., Kite Kite Track, Piha, Waitakere Range, 11. VI. 1963, J. M. D., PDD 30419 (DAOM 160105)

Ceratopycnidia scattered, erect, more or less cylindrical to slightly tapered toward their apex, usually straight: they are simple or up to six ceratopycnidia may be borne on a branched, robust black stalk up to 70 µm thick and the whole structure up to 750 µm long. They are black below, brown above and terminate in an ostiole 15-20 µm wide, which is fringed with the subulate, 1- or 2-septate, hyaline, slightly divergent, up to 30 µm long extensions of the parallel hyphae which form the neck. There is little or no indication of the location of the venter although some ceratopycnidia show a slight central] swelling. Conidia are more or less oblong with rounded ends to broadly ellipsoidal, 1-septate, at first hyaline, 7-9 x 3-3.6 µm, accumulating in a globule at the ostiole, later pale brown to brown, constricted at the septum and up to 13.5 x 7.2 µm either within the globule at the ostiole or on the host surface. Ascostromata subglobose, slightly extended at the apex, usually shortly stalked, 130-180 µm high (including the stalk) and 85-120 µm wide, dark brown to black and ostiolate at maturity. Asci bitunicate, 8-spored. Ascospores more or less obovoid, at first hyaline, soon becoming 1-septate with the upper cell broader and slightly to markedly shorter than the lower one which may taper to its end, finally transversely 3- to 5-septate with longitudinal septa in all, or all but the terminal cells, pale brown to brown, showing constrictions at the septa when outside the ascostromata, and measure 18-25(-27) x (7-)9-10(-11) µm.

This collection has been compared with the type, on Spartium sp. (probably S. junceum), Pennant Hills, N.S.W., Australia, VI. 1932, L. Fraser, DAR 19731.
In the New Zealand collection the mycelium forms a thin black stratum on the surface of the bark. Hyphae are repent, frequently branched and anastomosed, pale brown to brown and composed of oblong ceils up to 9 µm wide: broader hyphae, up to 15 µm wide, are found in the vicinity of ceratopycnidia and ascostomata.
Fraser (1935b) verified the connection between the ceratopycnidia and ascostromata by cultural methods.
The fungus described above is suitably disposed in Capnodium. The ceratopycnidia of C. uniseptatum are similar in general structure to those produced by other species and genera included by Hughes (1976) in a restricted Capnodiaceae; however, I know of no form generic name which can include them. The constantly 1-seplate conidia of Capnodium uniseptatum may be used to exclude the ceratopycnidia from Polychaeton (Pers.) Lev., Conidiocarpus Woronichin, and Scolecoxyplium Cif. et Bat. in which the conidia are nonseptate, from Fumagospora Arnaud, which produces dictyoseptate conidia, from Phaeoxyphiella Bat. et Cif. with fusoid multiseptate conidia, as well as from Catenuloxyphium Bat., Nasc. et Cif. which produces ellipsoidal 3-(4-) septate conidia. The ceratopycnidia of Capnodium uniseptatum are closest to those distinguished as Scolecoxyplium: whether the septate conidia of the former is sufficient to merit generic separation will become clearer as further investigations are made on these capnodiaceous sooty moulds.
The ceratopycnidia of Capnodium uniseptatum seem to fulfil the requirements of the diagnosis of Microxyphiella Spegazzini (1918). However, the type species M. fuligo (Berk. et Desm.) Speg. (= Capnodium fuligo Berkeley et Desmazieres 1849) has never been adequately redescribed and there is no evidence that Spegazzini saw any of the collections upon which this binomial is based.
Berkeley and Desmazieres described their fungus as follows "1. Capnodium fuligo, Berk. and Desm. Mycelio crassiusculo compacto a matrice secernibili; peridiis floccis processibusque ostioliformibus exasperatis; sporidiis minoribus. Gliotrichum Fuligo, Fr., Syst. Myc, Vol. III. p. 379. Dematium Fuligo, Schwein., pro parte."
'On leaves of Uvaria triloba, principally on the upper surface, Ohio; T. G. Lea, Esq. On leaves of various plants, Pennsylvania; L. V. Schweinitz'. The authors also included an expanded account of the fungus in English.
No collections labelled Dematium fuligo by Schweinitz have been traced in the Schweinitz collections at PH or amongst the Michener collections at BPI, and none has been found at K. I believe that the original illustrated account does not adequately explain Capnodium fuligo so that the generic name Microxyphiella that it typifies cannot be used with conviction. Hughes (1976) reported that several of the other species included in Microxyphiella by Spegazzini bear no morphological relationship to each other or to the generic diagnosis.
Batista and Ciferri (1963) used the generic name 'Microxyphiella Speg.' but excluded the type 'because it is an unrecognisable species': this is of course contrary to the 'International Code of Botanical Nomenclature'. The authors chose a neotype 'M. pernambucensis Bat., Cif., et Araujo'. and restricted the generic name to species with cylindrical, corniform or ampulliform pyenidia producing hyaline, finally 1-septate conidia. I haven't seen the type collection of M. pernambucensis but one of the five other species included, M. hibiscifolia Bat., Nasc., et Cif., is based on a Leptoxyphium according to the type collection (Hughes, 1976).
Relevant to a consideration of Capnodium uniseptatum is the name 'Microxyphiella commista Bat. and Cif., n. aux; Batista, Mycopath. et Mycol. Appi., Vol. V, p. 152 (1951)', as described in Batista and Ciferri (1963), 'on Clidemia, associated with Chaetopotius commistum Bat. Brasil'. Although the 1963 description is in English the reference to an earlier validly published Latin description of the 'pycnidia' of Chaetopotius commistum published by Batista (1951) validates the name Microxyphiella commista Bat. et Cif.
Batista and Ciferri (1963) then stated that 'Microxyphiella commista Bat. & Cif. n. aux.' is 'apparently ... the pycnidia] stage of Phragmocapnias salicina (Mont.) Cif. and Bat. [= Capnodium salicinum Mont.], described by Fraser (Proc, Linn. Soc. N. South Wales, Vol. I [sic], p. 98.1935) on Spartina'. However, Batista and Ciferri were actually referring to the description of the ceratopycnidia of Capnodium salicinum var. uniseptatum by Fraser (1935a); the brief English description included by Batista and Ciferri (1963) was clearly derived, for the most part, from Fraser's account. But this English description differs in several aspects from that which was published by Batista in 1951.
It is evident to me that the 'pycnidia' of Batista's (1951) illustrated account [of M. commista] are synnematous and not unlike those of Leptoxyphium or Ciferrioxyphium. But the 'pycnidia' described in 1963 by Batista & Ciferri are obviously the ceratopycnidia included in Capnodium salicinum var. uniseptatum) by Fraser (1935a).
It is not difficult to conclude that until the true type species of Microxyphiella is explained then the name cannot be used with any degree of certainty.
Batista, Nascimento, et Ciferri (in Batista & Ciferri, 1963) proposed the genus Astragoxyphium for simple or branched 'cylindric-lengthened' pycnidia producing pigmented 1-septate conidia. This generic name also is not suitable for the ceratopycnidia of Capnodium uniseptatum. Hughes (1976) reported that the type species of Astragoxyphium, A. calalpac Bat., Nasc., et Cif., is an obligate synonym of Capnodium axillatum Cooke which is best classified as Leptoxyphium axillatum (Cooke) Hughes. In the synnematous fructifications of this species, the originally hyaline, nonseptate conidia can develop a central septum and a pigmented wall.