SPECIMENS EXAMINED: MID CANTERBURY: Craigieburn Forest Park, Lyndon Saddle Track, on Nothofagus solandri var. cliffortioides, P. Clinton, P. K Buchanan 95/266, 15 Nov 1996, PDD 66487; no collecting data, on dead wood, G. B. Rawlings, PDD 6597.

BASIDIOCARPS probably annual, triquetrous to dimidiate, sometimes lobed; to 4.5 cm across, 4 cm radius and 2.5 cm thick; margin sharp; pileus surface glabrous or scrupose, concentrically zonate, orange-brown (58.m Br- 55.s Br) with several to few bands of dark grey; tubes to 9 mm long, yellow-brown to greyish-brown (76.1y Br- 80.gy.y Br), darker than context, non-stratose; pore surface pale brown (76.1y Br), discolouring with age to brown (75.deep.y Br), pores 2-5 per mm, mouths even or sometimes irregularly drawn out; context bright yellow-brown (72.d.OY - 74.s.y Br), paler than tubes, fibrous, to 10 mm thick, bounded above by a narrow dark band beyond which is a contrasting reddish brown tomentum; granular core basally present in context (though perhaps difficult to discriminate), arising towards point of attachment, with context tissue appearing slightly darker and denser and sometimes weakly flecked with spots of paler tissue. HYPHAL SYSTEM monomitic, though with branched hyphae resembling binding hyphae; generative hyphae brown, in context 3.5-8.5 µm diam., thick-walled to almost solid, wall thickened to 2.5 µm, simple septate with septa widely spaced, straight and mostly sparingly branched but with occasional narrower side-branches contorted and branched terminally; in granular core hyphae often wavy to contorted with convoluted and inflated apices to 12.5(-19.5) µm across, with walls thickened and brown, also with narrower, hyaline to brown, frequently branched hyphae 2.5-3.5 µm diam.; in trama hyphae straight, narrower than in context, 3-5.5 ltm diam. with wall thickened to 1.5 µm; at pileus surface hyphae as in context but with more frequent septa; setal hyphae absent. HYMENIAL SETAE brown, short ventricose with straight pointed apex, thick-walled except in newly formed setae near tube mouth, embedded in hymenium or projecting slightly beyond, 16-30 x 7.5-13.5 µm. BASIDIA subglobose to broadly ellipsoid, sometimes constricted towards apical region, 4-sterigmate (sterigmata to 3.5 µm long), septation at base not seen, 14-16 x 8-10.5 µm, typically viewed in preparations as either immature or collapsed during or following spore development. BASIDIOSPORES oval to broadly ellipsoid; in actively sporulating tubes spores hyaline, smooth, apiculus small or not evident, IKI-, with wall thickened to 1 µm, 6.7-9.2 x 5-6.3 µm; spores on pileus surface of some collections and in tubes of overmature pilel hyaline to light brown, mostly with a single large guttule and with wall thickened to 2 µm, 7.5-10.5 x 5.5-7.5(-8.5) µm. WOOD ROT not recorded.

New Zealand: Mid Canterbury. Australia: Victoria, South Australia.

SUBSTRATA: Known in New Zealand only from dead wood of Nothofagus solandri var. cliffortioides.

NOTES: This species is newly recorded from New Zealand. Walters (1955, as Inonotus dryadeus (Pers.: Fr.) Murrill) and Pegler (1964a) provided full descriptions, reporting conspicuous features including the granular core at the base of the context, presence of setae, and thick-walled spores. In New Zealand collections the basal granular core is easily over-looked macroscopically, but differences in hyphal microstructure of the core and context are evident when comparing microscope preparations of these tissues. Australian collections (PDD 12402, 13215, 16485, 16486, 20151) show a prominent core, and pilei are much larger, to 11 cm across, 7.5 cm radius, and 7 cm thick.
The thickness and colour of spore walls appear to gradually change with age of spores; younger spores present in tubes are hyaline and noticeably thinner walled (Fig. 7A) than older spores from the pileus surface or from overmature pilei (Fig. 7B, 8B), which varied in wall colour from hyaline to light brown.
Although the context has a layer separating it from the pileus surface, a feature diagnostic of Cyclomyces Fr., we follow Ryvarden (1991) and consider the species to belong in Inonotus P. Karst. on account of its robust fruit-body and large spores. The narrow, contorted, branched generative hyphae in the context are reminiscent of coltricioid hyphal construction as described by Corner (1991, fig. 11 right, fig. 30).
In Australia, where this species is known as the Austral Dryad, pilei are reported to develop from large swellings high up on trunks of Eucalyptus spp., often several pilei growing together. When fresh, pilei are of light weight and in active growth exude reddish droplets from the upper surface (Marks et al. 1982).
Inonotus chondromyelus is reported to be common in Victoria and South Australia (Walters 1955), but is known in New Zealand from only two collections. Along with several Australian collections, Cunningham (1965) mistakenly assigned his single New Zealand collection to I. rheades (Pers.) P.Karst. (as (Pers.) Bondartsev & Singer). I. rheades is a Northern Hemisphere species, restricted to Populus spp., which resembles I. chondromyelus in having granular core and a similar hyphal structure but differs in lacking setae and in spore size, 5-6 x 3.5-4 µm (Ryvarden & Gilbertson 1993). From I. dryadeus, the name earlier used in Australia for specimens of I. chondromyelus (e.g., Walters 1955), the latter differs in the presence of a granular core ellipsoid rather than subglobose spores, and straight not curved setae (Pegler 1964a).
Reid (1967) corrected Cunningham's (1965) mistaken synonymy of the names Polyporus albertii Lloyd (= Phaeolus albertinii (Lloyd) Reid) and Polyporus victoriensis Lloyd (= I. victoriensis (Lloyd) Pegler) under I. rheades; both are distinct species. Reid also expressed doubt that I. rheades occurs in Australasia, but in error cited the Australian species I. pirisporus Pegler as the correct name for collections labelled I. rheades by Cunningham. I. pirisporus is distinguished by its apiculate spores and absence of setae and of a granular core (Pegler 1964a, 1964b), and has not been recorded from New Zealand. I. victoriensis, described from Australia, differs in lack of a granular core, much larger pilei than those of I. chondromyelus, a loose hyphal structure in the context, and a well differentiated pilear crust (Pegler 1964b).
The only recorded New Zealand host, Nothofagus solandri var. cliffortioides, is also host to a common Inonotus species, I. nothofagi G.Cunn. (Cunningham 1965) which in the field might be confused with I. chondromyelus. I. nothofagi can be distinguished by the typically radially striate, often confluent pilei, absence of a granular core, and smaller, brown spores, 4.7-5.5 x 3.4-4.4 µm, with spore wall thickened to only 0.5 µm. Among 22 New Zealand collections labelled I. nothofagi in PDD, no collections of I. chondromyelus were found.

 

Pileus annual, sessile, 4-5.5 X 3-5 X 3-4.5 cm., dimidiate, ungulate, triquetrous in section, often imbricate or laterally confluent; at first `Dresden Brown', [Colour terms in quotes are from Ridgway, Color Standards and Color Nomenclature, 1912] `Tawny', or ferruginous, glabrous, soon developing a hard crust, becoming rimose, and at times radiately rugose especially towards the margin. Margin acute or obtuse, entire, undulate. Context up to 3 cm. thick, though thinner towards the margin. Characterized by a large core, situated at the base of the pileus; this may occupy a considerable proportion of the total volume, is of a granular nature, permeated throughout by white or yellowish flecks, and contains numerous conducting organs with yellowish or brownish contents. The remainder of the context which radiates out from the core is concentrically zoned, fibrous in texture, though watery and spongy when fresh, but soft and brittle when dry, and with a silky sheen. Colour varies from 'Buckthorn Brown' to `Tawny', but `Ochraceous Buff' or paler towards the pileus surface. Pore surface convex, often becoming concave towards the margin, ferruginous to dark umbrinous, narrowly sterile at the margin, usually covered by a cream-coloured pruina formed of secondary hyphae. Pores medium to large, irregular, round or angular, often becoming torn, 2-4 per mm., 170-620 µ diam., even. Tubes non-stratified, distinct from the context, ferruginous, but internally grey, brittle when dry, 2-14 mm. long; dissepiments 25-75 µ thick. Spores, few seen, 7.5-10 x 5.5-7 (8.5 x 6) µ, broadly ellipsoic; sometimes unilaterally flattened, with a small, lateral apiculus, smooth with a distinctly thickened, colourless or faintly brownish wall, occasionalh some found embedded within the tube layer or adhering to the pileus surface making it appear fulvous. Basidia large, colourless, 12-15 x 7-8 µ with 4 sterigmata. Setae present, not abundant, but occasionally localized in small groups, very thick-walled, but always with a lumen, dark chestnut-brown, appearing black in 10 % potassium hydroxide solution, 23-35 x 7-10 (-16) µ, ventricose to subulate. Setal hyphae absent. Context hyphae not agglutinated, dark ferruginous, with a thickened wall but a wide lumen, septate, branched, 4-10.5 µ, mostly about 5.5 µ diam. Tramal hyphae, tightly interwoven, not agglutinated, fulvous to ferruginous, very thin-walled, septate, rarely branched, 1.5-5 µ diam.

Pileus sessilis, dimidiatus, ungulatus, 4-5.5 cm. longus, 3-5 cm. latus, 3-4.5 cm. crassus. Superficies superior crusta glabra, ferruginea demum atrobrunnea; margine decurvato, obtuso vel acuto. Contextus usque 3 cm. crassus, brunneus sed crusta versus pallidus, radialiter fibrillosus, nucleo arenoso-granuloso praeditus. Tubuli 2-14 mm. longi; pori rotundati vel angulati, 2-4 per mm. (170-620 µ diam.), atro brunnei, dentati. Sporae 7.5-10 x 5.5-7 (8.5 x 6) µ, rarae, hyalinae, laeves, late ellipsoideae, muris crassis. Setae rarae, 23-35 X 7-10(-16) µ, muris brunneis crassis, ventricosae vel subulatae. Hyphae setoideae absunt. Hyphae contextus 4-10.5 µ diam., ramosae, septatae, crassitunicatae. Hyphae dissepimenti 1.5-5 µ diam., tenuitunicatae. Hab. in Eucalypto obliqua, Mt Lofty, South Australia. Ex-herb. J. B. Cleland. (Typus.)

This Australian species has hitherto passed under the name Inonotus dryadeus (Pers. ex Fr.) Murr. [as Polyporus dryadeus]. Cleland (1935),. following the advice given by Lloyd, used this name, though at the same time he suggested that his material might possibly not be the same as the European fungus. When a careful comparison is made of the Australian and European forms it becomes clear that a number of fundamental differences do occur, and that two species are involved though they are enough alike for the confusion in the past to be understandable. Both have a well-developed crust; the spores are large and colourless or nearly so; both have thick-walled, dark-staining setae; and apparently both are prone to exude watery droplets from the pileus surface.
The sporophore of I. chondromyelus, though often imbricate or laterally confluent, consists essentially of a medium-sized, ungulate pileus, which fruits high up on the trunk of the host, and this contrasts sharply with the large, more applanate habit of L. dryadeus, which fruits at or just above ground level. The spores of the former species, though similar in having a thickened wall, are broadly ellipsoid (8.5 x 6 µ) with a lateral apiculus, whereas those of L. dryadeus are subglobose (7.5 x 6.8 µ). The setae, too, are quite different in form, being straight and not curved with a larg, bulbous base. It is in the context that the most obvious distinctions are to be found: L. chondromyelus possesses a granular core, found at the base of the pileus because this is the first-formed structure of the fructification, and even though it may not be well developed it is nevertheless a constant feature which determines the thickness of the sporophore. In the remainder of the context the hyphae have thickened walls and a correspondinly narrower lumen. L. dryadeus never develops a core and the context is composed of thin-walled hyphae with a wide lumen. Other differences may be noted in the pore size and in the nature of the margin.
This species is known only from Australia, where it appears to be not uncommon and is apparently restricted to trunks of Eucalyptus (Walters,1955).