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STOYKE, G., and CURRAH, R. S . 1991. Endophytic fungi from the mycorrhizae of alpine ericoid plants. Can. J . Bot. 69: 347-352. Strains of a slow-growing, sterile, darkly pigmented fungus were obtained from alpine mycorrhizae of the Alberta Rocky Mountains. Sporulating isolates of this fungus from the roots of Cassiope mertetlsiana and Arctostaphylos uva-ursi (Ericaceae) as well as from Luetkea pectinata (Rosaceae) were identified as Phialocephala fortinii. Axenic cultures of Menziesia ferruginea (Ericaceae) seedlings were grown with P. fortinii for characterization of the fungus-root association. Typically, dark, simple septate hyphae form extensive wefts on the root surface and produce intracortical sclerotia of compact, darkly pigmented and irregularly lobed, thick-walled hyphae. Intracellular coils are not produced. This association differs from the ericoid mycorrhizal type and represents a fungus-root association that is common in alpine plants. In addition, several isolates of Oidiodendron griseum, a species previously reported from mycorrhizae of ericaceous plants, were found to form intracellular coils within the cortical root cells of Loiseleuria procumbens (Ericaceae). STOYKE, G., et CURRAH, R. S. 1991. Endophytic fungi from the mycorrhizae of alpine ericoid plants. Can. J. Bot. 69 : 347-352. A partir des mycorhizes de plantes alpines provenant des Montagnes Rocheuses en Alberta, les auteurs ont obtenus des isolats fongiques constitues de mycCliums stCriles B pigments fonces et B croissance lente. Des isolats de tels champignons provenant des racines du Cassiope mertensiana et de 1' Arctostaphylos uva-ursi (EricacCes) ainsi que du Luetkea pectinata (RosacCes) ont ete identifies comme Phialocephala fortinii. Afin de caractiriser l'association champignon-racine, les auteurs ont co-cultivC le P. fortinii avec des plantules de Menziesia ferruginea (Ericacdes) en culture aseptique. Des hyphes typiques, fonces et septe ont form6 des touffes extensives sur la surface racinaire en produisant des sclt5rotes intra-corticales constituCs d'hyphes a paroi Cpaisse, a pigmentation fon~Ce et irrkgulikrement lobCs. Cette association diffkre du type mycorhizien ericoi'de et represente une association champignon-racine commune chez les plantes alpines. De plus, les auteurs montrent que plusieurs isolats de l'Oidiodendro~z griseum, une espkce dCjB obtenue a partir de mycorhizes Cricoi'des, forme des pelotons intracellulaires dans les cellules corticales racinaires du Loiseleurai procumbens (EricacCes).

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The seasonal development and mycorrhizal fungi of the mycorrhizae of Platanthera hyperborea, Platanthera obtusata, Platanthera orbiculata, and Coeloglossum viride are described. Fungal endophytes belonging to the following taxa were identified: Leptodontidium orchidicola, Epulorhiza repens, Epulorhiza anaticula comb, nov., and Ceratorhiza goodyerae-repentis. In addition, anamorphic material of a species tentatively identified as Sebacina sp. was found solely in the mycorrhizae of P. orbiculata. A series of isolates bearing distinctive, clamped monilioid cells and belonging to an unidentified species of Sistotrema was found in P. obtusata. This is the first report of a Sistotrema species from orchid mycorrhizae. An isolate from C. viride, with broad hyphae, large globose monilioid cells, and dark brown mycelium, resembles Burgeff's 1936 description of Rhizoctonia anomala nom.inval. This taxon is validated, redescribed, and presented as the new species Moniliopsis anomala.

STOYKE, G., ECCER, K. N., and CURRAH, R. S. 1992. Characterization of sterile endophytic fungi from the mycorrhizae of subalpine plants. Can. J. Bot. 70: 2009-2016. Isolates of 117 dematiaceous and 10 hyaline, septate, sterile fungi were obtained from the roots of 26 plants belonging to Poaceae, Caryophyllaceae, Rosaceae, Ericaceae, Primulaceae, and Asteraceae from a subalpine dwarf shrub heath in the Alberta Rocky Mountains. The isolates were sorted into 33 culture groups based on colonial morphology. Strains representative of the different culture groups were compared with fungi of known identity (Cenococcutn geopl~ilutn, Hynzerzoscyplz~~s ericae, Pllialocephala dirnorphospora, Phialocephala fortirzii, Phialophorafinlandia) using restriction fragment analysis of an amplified portion of ribosomal DNA. Cluster analysis and ordination based on restriction fragment polyn~orphisms indicated that two-thirds of the isolates were closely related to or conspecific with Plzialoceplzala fortinii, which therefore appears to represent the dominant root endophyte of the subalpine site. In culture, many of the Plzialocephala fortirlii isolates had sclerotia con~posed of compact masses of darkly pigmented and irregularly lobed, thick-walled hyphae. Five of the isolates clustered independently of the known isolates and are probably each representative of species other than the known strains. Key words: subalpine mycorrhizae, Plzialocephala fortinii, restriction fragment length polymorphism, ribosomal DNA. STOYKE, G., ECCER, K. N., et CURRAH, R. S. 1992. Characterization of sterile endophytic fungi from the mycorrhizae of subalpine plants. Can. J. Bot. 70 : 2009-2016. Les auteurs ont obtenus 127 isolats de champignons stCriles septCs dont 117 sont den1atiacCs et 10 hyalins, h partir des racines de 26 plantes appartenant aux Poaceae, Caryophyllaceae, Rosaceae, Ericaceae, Primulaceae et Asteraceae; ces plantes appartiennent h une lande arbustive subalpine des montagnes Rocheuses en Alberta. Les isolats ont Ctk sCparCs en 33 groupes de culture en se basant sur la morphologie des colonies. Des souches reprksentatives des differents groupes ont CtC comparCes avec des champignons dont llidentitC est connue (Cenococc~lm geophilum, Hymenoscyphus ericae, Phialoceplzala dirnorphospora, Phialocephala fortinii, Pl~ialophorafinlandia), en utilisant I'analyse des fragments de restriction d'une partie de 1'ADN ribosomique amplifiC. L'analyse par groupement et ordination basCe sur le polymorphisme des fragments de restriction indique que deux tiers des isolats sont trks voisins ou conspCcifique avec Pl~ialocephala fortinii, qui semble par consCquent reprksenter I'endophyte racinaire dominant sur ce site subalpin. En culture, plusieurs des isolats du Phialocephala fortinii montrent des sclkrotes composCs de masses d'hyphes Cpais, conlpacts, fortement pigment& et irrtgulikrement lobes. Cinq isolats se retrouvent dans un groupe indkpendant des isolats connus et reprksentant probablement des espkces autres que celles des souches de refkrence utilis...

The morphology of the interaction of three strains of Phialocephala fortinii with the roots of Rhododendron brachycarpum was examined by light, scanning, and transmission electron microscopy using material grown in axenic Petri dish cultures and in nonsterile pot cultures. In Petri dish cultures, Phialocephala fortinii quickly overwhelmed root tips of young seedlings, causing distortion of cells of the root apex and inhibition of elongation. In older roots, mature, vacuolated, and moribund epidermal cells were penetrated. In pot-cultured plants the epidermis was heavily colonized by hyphae growing parallel to the long axis of the root. Microsclerotia formed within individual cells, between the epidermal and the subepidermal layers, and within cells surrounding the point of emergence of lateral roots. Hyphae did not invade the stele. The effects of two strains of Phialocephala fortinii on shoot dry weight accumulation of R. brachycarpum grown in pot culture were examined and compared with the effects of Hymenoscyphus ericae, Myxotrichum stipitatum, Oidiodendron echinulatum, and Pseudogymnoascus roseus. One strain of Phialocephala fortinii had a significant negative effect on dry weight accumulation, whereas a second had no effect. Hymenoscyphus ericae had a positive effect. The remaining fungi had no effect. One strain of Phialocephala fortinii gave rise to what appeared to be sterile discocarps on the surface of soil in 4-month-old pots of R. brachycarpum. Key words: Phialocephala fortinii, Hymenoscyphus ericae, microsclerotia, Rhododendron brachycarpum, ericoid mycorrhizas, Mycelium radicis atrovirens.

Corallorhiza trifida Châtelain, or pale coral root orchid, is a heterotrophic, leafless, rootless, terrestrial orchid with a circumboreal distribution. Because of its relative inability to photosynthesize, the orchid obtains energy through the digestion of fungal hyphae that grow within the cells of its contorted, yellowish, coralloid rhizomes. Recently, we isolated and cultured strains of a slow-growing basidiomycete with bright yellow, clamped hyphae that are typical of the fungal cells present in C. trifida endomycorrhizas from different treed habitats at widely distributed locations in the northern hemisphere. By inoculating the roots of Pinus contorta Douglas ex Loudon seedlings with this fungus we were able to demonstrate its ability to form distinctive ectomycorrhizas with an ectotrophic, woody plant. The formation of endomycorrhizas with C. trifida and ectomycorrhizas with P. contorta indicates that in nature a triple symbiosis, with a circumboreal distribution, exists among certain trees, the coral root orchid, and this yellow basidiomycete that links the two and functions as a mycorrhizal symbiont in both. Key words: Corallorhiza trifida, orchid mycorrhiza, triple symbiosis, ectomycorrhiza, Pinus contorta.

Two new species of fungi mycorrhizal with terrestrial orchids native to the Canadian prairies are described and illustrated. Ceratorhiza pernacatena sp.nov., from mycorrhizas of Platanthera praeclara, produces globose monilioid cells linked by narrow, tubular, connections that contain the septum between adjacent cells. Hyphae are binucleate, 5–7 μm in width, regularly septate with perforate parenthesomes. Cellulase is produced, but polyphenol oxidase production is low to absent. Epulorhiza calendulina sp.nov., from mycorrhizas of Amerorchis rotundifolia, is distinguished from other Epulorhiza species by the orange to ochre colour of colonies on potato dextrose agar. On corn meal agar, clavate to irregular monilioid cells are produced in short, branched, chains arising from lateral hyphal branches. Runner hyphae are binucleate, 3.0–4.7 μm in width, regularly septate, with flattened, imperforate parenthesomes. Polyphenol oxidase production is lacking, but cellulase is produced. Key words: orchid mycorrhizas, Amerorchis rotundifolia, Platanthera praeclara, Rhizoctonia.