First Report Echinodontium tinctorium Sporophores on Larix occidentalis. J. E. Taylor, Forest Health Protection; USDA Forest Service, Missoula, MT 59807; O. C. Maloy, Washington State University, Pullman 99164. H. Desy, USDA Forest Service, Troy, MT 59935; and R. R. Bryant, USDA Forest Service, Missoula, MT 59801. Plant Dis. 80: 1301. Accepted for publication 14 August 1996. Copyright 1996 The American Phytopathological Society. DOI: 10.1094/PD-80-1301C.
Echinodontium tinctorium (Ellis & Everh.) Ellis & Everh. causes heart rot in conifers throughout the western United States and Canada. Species of Abies and Tsuga are the common hosts, and Pseudotsuga menzjesii (Mirb.) Franco and Picea engelmanii Parry ex Engelm. are rarely infected. There have been unverified reports of other hosts of E. tinctorium, but no reports of sporophores appearing on any other hosts (I). In 1992, two sporophores were collected from a single western larch (Larix occidentalis Nutt.) tree in Lincoln County in northwestern Montana. In 1993, another E. tinctorium sporophore was collected from a western larch tree, this time in Sanders County, MT, approximately 140 kilometers southeast of the first collection. One of the 1992 samples was a sporophore severed from the tree at lime of collection, and the other was a 2-foot section of western larch with the sporophore attached; the heartwood of the larch section was extensively decayed. The 1993 sample consisted of a single sporophore broken from the tree at time of collection. At each collection site, conks were found only on the trees from which the samples were taken. All samples were sent to the USDA Forest Service Forest Health Protection Laboratory, Missoula, MT, for identification. All sporophores had the morphological characteristics of E. tinctorium: the sporophores were perennial, woody, and hoof-shaped; the upper surface was dark, rough, and cracked; the under surface consisted of hard coarse teeth; and the context was brick red. Isolations were made from each sporophore and from the log sample. The cultures were grown on malt, Nobles's, and tannic agars at room temperature for 6 weeks. The isolates were identified as E. tinctorium with Nobles's Key (2). A sample sent to the USDA Center for Forest Mycology Research, Madison, WI, was also identified as E. tinctorium.References: (1) S. D. Hobbs and A. D. Partridge For. Sci. 25:31. 1979. (2) M. K. Nobles. Can. J. Bot. 43:1097, 1965.