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Hughes, S.J. 1975: New Zealand fungi. 24. Capnokyma corticola gen. nov. , sp. nov., a hyphomycetous sooty mould. New Zealand Journal of Botany 13(4): 637-644.

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Hughes, S.J. 1975: New Zealand fungi. 24. Capnokyma corticola gen. nov. , sp. nov., a hyphomycetous sooty mould. New Zealand Journal of Botany 13(4): 637-644.
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(1) on Ackama rosaefolia, North Auckland, Omahuta Forest, 19.VI.1963, J. M. Dingley, PPD 21244 (DAOM 97062): (2-8) Auckland Prov.; (2) Hoheria populnea, Waiatarua, Waitakere Range, 8.V.1963, DA0M 93838; (3) Neopanax arboreum [Pseudopanax arboreus] , Pureora, 21.III.1963, DAOM 97056; (4-7) 0learia rani; (4) Titirangi, 27.11.1963, J. M. D., DAOM 97055; (5) Fairy Falls Track. Waitakere Range, 7.VIII.1963, J. M. D., PDD 21395 (DAOM 97059); (6) Waiatarua, 8.V.1963, DAOM 97045, (7) Waiatarua, 8.V.1963, PDD 30412 (type) (DAOM 97054); (8) on unidentified host, summit of Whitianga Rd, Coromandel Peninsula, 21.VIII.1963, J. M. D., DAOM 97057.

Capnokyma corticola is also present on periderm in a collection preserved in Herb. K, labelled -Antennaria. New Zealand [scr Berkeley]. Herb. Berk. 1879.

Colonies are black and extensive, forming a velutinous growth on trunks and branches of trees, often mixed with Acrogenotheca elegans. The mycelium is superficial although often found in the cracks of rough bark: it is composed of repent and erect aerial hyphae. The repent hyphae are cylindrical, smooth or faintly roughened, straight or variously bent, pale brown to brown, occasionally anastomosing, branched generally at right angles, septate, not constricted at the septa. Cells of repent hyphae are 25-40 um long and 7.2-12.6 um wide; the walls are 1.8-2.0 um wide and their double nature is conspicuous. At intervals, cells of the repent hyphae are darker, wider, and somewhat constricted at the septa; erect hyphae arise singly from one of these more robust cells and rooting hyphae appear to arise from the basal cell. The erect hyphae show considerable variation in size, form, and degree to which they are modified into conidiophores; nevertheless it is convenient to describe the sterile erect hyphae, those hyphae which are entirely conidiogenous, and finally some of the intermediate forms (Fig. 1).

Sterile erect hyphae are up to 1.3 mm long, straight or flexuous, smooth throughout, and stand out at right angles to the substratum. They are composed of a main stalk which is almost cylindrical for most of its length, 18-30 um wide near the base, then expanding gradually to 25-33 um wide and finally tapering subulately to an almost acute apex: they are dark brown to almost black at the base, becoming paler toward the apex which is pale brown. Basal cells are 32-40 um long and then progressively shorter and 12.5-21.5 um long toward the distal end. This main stalk bears, toward the apex and produced in the same plane, 1 to 5, mostly 2 or 3 paired subulate, distally pointed, pale brown to subhyaline, lateral branches, the upper ones successively shorter: these branches are upwardly curved and the more robust ones may bear secondary paired lateral branches. It is not uncommon for only a solitary branch to arise from one cell, but most erect hyphae bear at least one pair of opposite branches. The outer wall of all lateral branches is continuous with the inner wall of the main stalk which, during extension, has burst through the outer wall layer: at the base of lateral branches the torn remains of the outer wall of the main stalk appear as an irregular frill. Erect hyphae modified entirely into conidiophores are often darker throughout than sterile hyphae, almost cylindrical, up to 1.4 mm long, 20-27 um wide at the base. expanding gradually to 25-30 um wide about half way along their length and then tapering gradually to 12.5-18 um wide at the apex. Conidiophores may be unbranched structures bearing a terminal conidium, or they may also produce solitary or paired, lateral, cylindrical, upwardly curved branches which also bear a terminal conidium. Such cylindrical lateral branches can take the place of one or more of the subulate lateral branches of otherwise sterile erect hyphae. Also, sterile subulate paired or solitary branches may develop on otherwise simple conidiophores. The result is an almost infinite variety of branching structures, some of which are illustrated in Fig. 1.

Conidia arise blastically and their narrowed origin is indicated by a darker zone of wall on both apical cell of the conidiophore and basal cell of the conidium. At maturity, conidia are pale brown to brown, smooth, obclavate, slightly or markedly curved, (6-)8-10(-11)-septate, barely or only slightly constricted at the septa, (90-) 100-130(-150) um long and (20-)21-24(-27) um wide. Occasionally a conidiophore has proliferated through the terminal scar left by a seceded conidium and the extension has produced another terminal conidium. Any cell of a conidium can germinate and paired hyphae arising from a single cell have been seen.

Erect hyphae may bear a Horn i i.ycioniyces phialidic state, terminally on one or more lateral branches. The phialides are borne in a whorl of 6 or 7: they are pale brown, flask-shaped with the venters 4.5-5.5 um wide, each with a short neck, 2.0-2.2 um long, directed inwards toward the centre of the whorl. Phialoconidia are hyaline. broadly ellipsoidal, c. 2.5 X 1.5 um, and produced in a slimy head. Hormisciomyces phialides have been observed on simple and on branched hyphae arising from germinating Capnokyma conidia.

on bark of living trees, New Zealand
Coloniae corticolae effusae. Subiculum atrum, ex hyphis superficialibus repentibus et ex hyphis erectis compositum. Hyphae repentes cylindricae, leves vel parce asperae, pallide brunneae vel brunneae, ramosae, anastomosantes, septatae, ex cellulis oblongis 25-40 x 7.2-12.6 um, crasso-tunicatis (1.8-2.0 um) compositae. Hyphae erectae simplices vel varie ramosae, ad 1.4 mm long., steriles vel fertiles. Hyphae erectac steriles, forma variabile, septatae, ad basim atrobrunneae vel atrae, 18-30 um lat., dein 25-33 um, apicem versus subulatae et pallide brunneae. ramis (1-)2-3(-5) plerumque oppositis, incurvatis, aliquando ramulis secondariis plerumque opposite praeditis. Hyphae fertiles (conidiophorae) brunneae vel atrobrunneae, plus minusve cylindricae, ad basim 20-27 um lat., dein 25-30 um lat., apicern versus 12.5-18 um lat- simplices vel ramosae, ramis cylindricis oppositis vel solitariis: conidiophorae simplices atque corum rami cylindrici in conida singula desinentes. Necnon hyphae fertiles ramis ramulisque subulatis sterilibus solitarfis vel oppositis praeditae. Conidia obclavata. pallide brunnea vel brunnea, levia. parce vel fortiter curvata, (6-)8-10(-11)-septata. ad septa parum constricta.(90-)100-130(-150) x (20-)21-24(-27) um. Status Hormisciomyces infrequens. in hyphis erectis oriunda. Phialides ampullaccac. 6 vel 7 in coronam circa apicem phialophorarum dispositae. pallide brunneac. 4.5-5.5 um lat.. collo 2.0-2.2 um long. Phialoconidia hyalina. late ellipsoidea, c. 15 x 1.5 um in muco producta.
Capnokyma corticola is reminiscent of Acrogenotheca elegans in the production of cylindrical, repent hyphae and distinctive erect, branched aerial hyphae. In A. elegans, however, the erect hyphae, which are usually much longer (up to 4.1 mm), are never oppositely branched: furthermore, in this species micro conidia are produced in pycnidia, and branches of the erect hyphae can secede and function as conidia. In Capnokyma corticola branching of the erect hyphae is characteristically opposite, and micro conidia are produced by Hormisciomyces phialides borne on the erect hyphae: Capnokyma macro conidia, which are reminiscent of those of Antennatula (Hughes 1970), develop either on distinctive macronematous conidiophores or on certain branches of aerial hyphae. I consider these to be significant differences, and notwithstanding the superficial similarities between Acrogenotheca elegans and Capnokyma corticola I regard these two fungi as showing no true affinity: we have instead a splendid example of convergent evolution in a distinctive ecological niche.
In Antennatula, the phragmoconidial state of species of Euantennaria Speg. (Euantennariaceae - Dothideales - Loculoascomycetes) (Hughes 1972), the conidia develop usually laterally either on repent hyphae or on aerial hyphae which are scarcely or not at all different from the repent hyphae. In Trichopeltheca Batista, Costa, & Ciferri (Hughes 1965), also included in Euantennariaceae, the Trichothallus Stevens phragmoconidia are sessile on repent hyphae which are characteristically united into a plate which is one cell thick. The thallus of Trichopeltheca does, however, produce erect setae, quite different from the hyphae of the repent thallus: similar setose structures on the same thallus can produce Plokamidomyces Batista, Costa, & Ciferri phialides at their apex.
In spite of the lack of ascostromata of Capnokyma, the evidence of conidial and vegetative states strongly suggests a close relationship to Euantennariaceae. Discovery of the ascostromata will decide.
: in cortice trunci Oleariae rani, Auckland Province, Waiatarua, Waitakere Range, 8.v.1963, PDD 30412 (DAOM 97054).
Coloniae atrae superficiales. Mycelium dematiaceum ex hyphis superficialibus, repentibus, cylindricis et hyphis erectis, distinctis, variabilibus. Latioribus, simplicibus vel ramosis, sterilibus vel fertilibus, vel parte sterile et parte fertile. Conidia singula ex apice hyphae fertilis (conidiophorae) simplicis vel ramosae oriunda, Obclavata, dematiacea, multiseptata.
Nine collections of a pleomorphic sooty mould on the bark of living Ackama rosaefolia A. Cunn., Hoheria populnea A. Cunn., Pseudopanax arboreus (Murr.) Philipson, Olearia rani (A. Cunn.) Druce, and of an unidentified tree, from New Zealand, produce superficial, repent, cylindrical hyphae from which arise a velutinous growth of distinct erect hyphae bearing paired, lateral, upwardly curved branches. Terminal, brown, blastic phragmoconidia develop on simple or sparingly branched erect conidiophores or on one or more branches of otherwise sterile erect hyphae: this state is described as the type of a new form genus Capnokyma. A Hormisciomyces phialidic state is borne on the erect hyphae.
Typus: Capnokyma corticola sp. nov.

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18 March 2001
3 April 2001
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