Thelephoraceae of New Zealand
Part V. The Genus Asterostroma
[Read before the Auckland Institute and Muscum, August 16, 1954; received by the Editor, November 17, 1954.]
Asterostroma differs from Corticium by the presence in the context of stellate setae, coloured organs composed of 3-9 aculeate rays radiating from a central inflated boss. Two species have been collected in New Zealand. A. persimile Wakef. first found near Rotorua, occurs in Australia and probably extends to Malaya. A. andinum Pat. has been recorded from North and South America, and the West Indies.
Characterized by the abundant stellate setae forming the bulk of the context tissues, Asterostroma is a small genus of about ten species with a wide though erratic distribution. It is represented in New Zealand by two species, A. andinum Pat. with a distribution through North and South America and the West Indies; and A. persimile Wakef. which extends to Australia and possibly Malaya. Species resemble those of Corticium in arrangement of context and hymenium, differing in the presence of one or two types of ancillary organs—namely, stellate setae and asterophyses.
Stellate setae are brown in colour and crowded in the context. Each consists of a slightly enlarged central boss from which radiate 3-9 aculeate ravs, terminating in acute apices. Rays are usually simple but occasionally, especially in two species, may be bifid near the ends. They arise from lateral branches of generative hyphae. Largest near the base, they become progressively smaller towards the hymenium. Though confined to this genus of the Thelephoraceae, they occur in Asterodon of the Hydnaceae, and somewhat similar organs are present in two or three other species of basidiomycetes.
Asterophyses are confined to the hymenial region, where they form a conspicuous palisade of irregular bodies bearing 3-several radiating short acuminate spines which are often bifid. Each asterophysis is carried on the apex of a simple stem; occasionally two, three, or more, may be attached in the form of a short chain to the same stem. Most are hyaline, and stain deeply with aniline blue, though sometimes those nearest the base may be tinted brown. Like stellate setae, asterophyses arise from branches of the generative hyphae. They have been noted in but two species, A. persimile and A. muscicolum (Berk. & Curt.) Mass.
Gloeocystidia were present in all species examined in Kew herbarium. They are confined to the hymenial region, and may project to 50μ above the surface. All possess naked, thin, hyaline walls and granular contents staining blue, interspersed with large oil globules.
The species present in the Dominion may be identified readily by the spores. In A. andinum spores are smooth and provided with long pedicels, in A. persimile they are coarsely and scantily echinulate-verrucose.
6. Asterostroma Massee, Journal of the Linnean Society, 25, 154, 1889.
Gloeoasterostroma Rick, Brot. Cienc. Nat., 7, 75, 1938.
Hymenophore resupinate, annual or biennial, membranous, effused; hyphal system monomitic, generative hyphae hyaline, septate, branched, without clamp connections. Context composed of a basal layer of parallel hyphae, and an intermediate layer of scanty irregularly woven hyphae, associated with very numerous coloured stellate setae. Hymenial layer composed of a palisade of basidia and paraphyses associated with gloeocystidia and, in some species, asterophyses. Basidia cylindrical or subclavate, projecting at maturity, bearing 2-4 spores on slender sterigmata. Asterophyses hyaline or tinted yellow-brown, irregularly clavate, bearing several radiately arranged brief acuminate arms, attached to long simple pedicels, sometimes arranged in chains of two or three. Stellate setae brown, composed of a central enlarged area or boss from which radiate in one plane 3-9 aculeate naked rays, becoming progressively smaller from base to hymenial layer. Gloeocystidia clavate or fusiform, hyaline, thin-walled, naked. Spores smooth or variously warted, hyaline, globose or subglobose.
Type Species. Asterostroma apula Mass.
Distribution. North and South America, Europe, East and West Indies, Ceylon, Japan, Australia, New Zealand.
1. Asterostroma andinum Patouillard, Bulletin de la Societe Mycologique d'France, 9, 133, 1893.
Asterostroma bicolor Ell. & Ev., Proc. Acad. Nat. Sci. Philadelphia. 441, 1894.
A. spiniferum Burt., Ann. Missouri Bot. Gard. 11, 33, 1924.
A. gracile Burt, l.c., 34.
Hymenophore annual, membranous, loosely attached, effused forming small irregular areas 1-5 × 1-3 cm, rhizomorphic; surface ochraceous or dingy ferruginous, even, at length creviced irregularly, sometimes pruinose; margin thinning out, fibrillose, loosely attached, concolorous, rhizomorphs scanty but always present, white. Context fuscous in section, to 200μ thick, composed of a dense basal layer varying in thickness of parallel hyphae, and an intermediate layer of loosely arranged hyphae embedding masses of stellate setae; generative hyphae 3-3. 5μ diameter, wall 0. 2μ thick, hyaline, branched, septate, with occasional bridging hyphae. Hymenial layer to 70μ deep, scanty, composed of basidia, paraphyses and gloeocystidia interrupted by occasional projecting rays of the stellate setae; asterophyses absent. Basidia cylindrical or slightly constricted in the middle, projecting, 30-36 × 7-9μ, 4-spored; sterigmata slender, to 6μ long Paraphyses subclavate, about half the length of the basidia Gloeocystidia arising in the subhymenium and projecting 10-20μ, commonly fusiform, some subclavate, apex bluntly acuminate with a small acute apiculus, 40-54 × 10-12μ, wall 0. 5μ thick. Stellate setae densely compacted in the intermediate layer, somewhat scanty near the base, to 120μ diameter, chestnut-brown, with 4-6 naked aculeate rays, some bifid, to 64μ long, wall to 2μ thick. Spores globose or subglobose, some almost pyriform, 6-7μ diameter, long apiculate, wall hyaline, smooth, 0. 25μ thick.
Type Locality. Quito, South America.
Distribution North and South America, Porto Rico, New Zealand.
Habitat. Effused on decayed bark or decorticated wood.
Dacrydium sp. Taranaki. Mt. Egmont, 3,000ft, March, 1952, J. M. Dingley.
Nothopanax colensoi (Hook. f.) Seem. Taranaki, Mt Egmont, 3,000ft, March, 1951, J. M. Dingley.
Pseudowintera colorata (Raoul) Dandy. Auckland. Hauhangaroa Range, Taupo, 2,200ft, March, 1953, J. M. Dingley.
Specific features are the globose, smooth, strongly apiculate spores, relatively small gloeocystidia, and absence of asterophyses. Our collections agree with a specimen of A. andinum seen in Kew herbarium. They differ from A. laxum Bres., which also has smooth globose spores, by the larger stellate setae and gloeocystidia and absence of asterophyses. Synonyms are given on the authority of Rogers & Jackson (Farlowia, 1, 271, 1943) who examined types of all four species listed.
2. Asterostroma persimile Wakefield, Kew Bulletin of Miscellaneous Information, 372, 1915. Fig. 1.
Hymenophore annual, often reviving a second season, sometimes vaguely stratose, membranous, loosely attached, effused forming irregular areas to 10 × 6 cm; surface clay colour, tan, bay-brown or ochre, according to age and hymenial development, even, sometimes pruinose, at length scantily creviced; margin thinning out, clay colour or tan, fibrillose, loosely attached, rhizomorphs rare, when present pallid tan. Context tan or ferrugmous, 250-900μ thick, composed of a thin base of parallel hyphae, an intermediate layer of scanty woven hyphae and masses of stellate setae which are progressively smaller and lighter in colour from base to surface; sometimes obscurely stratose; generative hyphae 2. 5-3. 5μ diameter, wall 0. 2μ thick, hyaline, branched, septate. Hymenial layer 60-130μ deep, of basidia, paraphyses, gloeocystidia and asterophyses arranged in a loose palisade. Basidia cylindrical, a few subclavate, projecting, 24-32 × 5-6μ, 4-spored; sterigmata slender. to 6μ long. Paraphyses subclavate, about half the length of and narrower than the basidia Gloeocystidia confined to the hymenial layer, projecting to 30μ, or not, fusiform or subclavate with bluntly acuminate apices, 80-110 × 10-14μ, wall naked, 0. 5-1μ thick, hyaline. Asterophyses forming the bulk of the hymenial layer, sometimes arranged in several vague zones, composed of subclavate bodies bearing 4-7 short aculeate rays which are sometimes once or twice bifid, attached to long and narrow pedicels often freely geniculated, and sometimes bearing two or three asterophyses in chains. Stellate setae chestnut-brown, 25-150μ diameter, composed of 3-7 commonly 4-5 aculeate rays each 15-80μ long, attached radiately to a slightly inflated boss, sometimes bifid. Spores globose or subglobose, appearing angular, 7-10μ diameter (including spines), wall hyaline, 0. 5μ thick, coarsely echinulate-verrucose, spines acuminate, to 3μ long.
Type Locality. Rotorua, New Zealand.
Distribution. New Zealand, Australia, Malaya?
Habitat. Effused on decayed bark or decorticated wood.
Agathis australis Salisb. Auckland. Manaia, Whangarei Heads, 500ft, October, 1947, J. M. Dingley.
Beilschmiedia tawa (A. Cunn.) Hook. f. & Benth. Auckland. Waiotapu, 1,800ft, June, 1950, J. M. Dingley. Te Whaiti, 1,500ft, June, 1951, J. M. Dingley. Orere, Hunua Range, March, 1953, J. M. Dingley.
Cordyline australis (Forst. f.) Hook. f. Auckland, Manaia, Whangarei Heads, 500ft, October, 1947, J. M. Dingley.
Knightia excelsa R. Br. Auckland Waipoua Kauri Forest, December, 1951, M. E. Lancaster.
Melicytus ramiflorus Forst. Auckland Purewa Bush, April, 1953, D. W. McKenzie.
Nothofagus fusca (Hook. f.) Oerst. Wellington. Day's Bay, February, 1927, D. W. McKenzie.
Nothopanax arboreum (Forst. f.) Seem, Auckland, Anawhata Road, Waitakeres, 1,000ft, November, 1948, J. M. Dingley. Kauri Glen, Northcote, August, 1951, J. M. Dingley.
Suttonia salicina Hook. f. Auckland. Cutty Grass Road, Waitakeres, 900ft, August, 1947, J. M. Dingley.
Weinmannia racemosa L.f. Otago. Ulva Islet, Stewart Island, February, 1954, J. M. Dingley.
Unknown hosts. Auckland. Rotorua, W. N. Cheesman, 1914, type collection, in Kew herbarium. Hunua Range, 1,000ft, May, 1949, J. M. Dingley.
Separated readily from other species, save A. medium Bres., by the coarsely verrucose-echinulate spores. Spines of these are large, with broad bases and acuminate apices, and give to spores an angular appearance though they are globose or subglobose. Although the spores resemble those of A. medium, our species differs in the presence of abundant asterophyses, larger gloeocystidia and much thicker often stratose context.
Surface colour varies appreciably. When sterile plants are darker since many of the coloured stellate setae project; when fertile they assume a lighter colour and often appear pruinose owing to the projecting gloeocystidia. The hymenial layer may be pulled off readily since it is feebly attached by the scanty generative hyphae.
A collection of A. persimile from Australia is in Kew herbarium, donated by the late C. G. Lloyd; and it is possible that it occurs also in Malaya since a drawing by Corner (Trans. Brit. Myc. Soc., 31, 242, 1948) could well be of this species.
G. H. Cunningham, D.Sc, Ph.D., F.R.S.
Plant Diseases Division