Tholurna dissimilis in Oregon

Tholurna dissimilis has been found in the state of Oregon onCarpenter Mtn., 300 km south of the Mt. Rainier localities in Washington.
Tholurna dissimilis Norm. (Caliciales, Sphaerophoraceae), once thought to beendemic to Scandinavia, is known from several localities in British Columbia and thestate of Washington (Otto, 1972). Since its discovery on the Olympic Peninsula andon Mt. Rainier during the XI International Botanical Congress (Otto, 1970), I havebeen trying to locate Oregon populations. Until recently my searches, which includedthe vicinities of Mt. Hood and Mt. Jefferson, have failed to turn up populations ofTholurna.
The first known locality for Tholurna in Oregon is in the H. J. Andrews Experi-mental Forest, 75 km east of Eugene in Linn County. This forest is located in theWestern Cascades and is an intensive study site for the Coniferous Forest Biome ofthe International Biological Program. Tholurna was discovered growing on twigs ofAbies lasiocarpa (Hook.) Nutt. about 3 m below and to the northeast of the rockysummit of Carpenter Mtn. (122°8'W, 44°17'N; 1630 m alt.). My collection (Pike3083) is from the tree closest to the summit. This tree is about 2 m high and stunted;it has been heavily infested by Adelges piceae (Ratz.), the balsam woolly aphid. Thethalli of Tholurna are poorly developed and are widely scattered along the needle-bearing portion of the twigs (Fig. 1, 2). Within about 10 m from this tree additional,healthy individuals of Tsuga mertensiana (Bong.) Sarg., Taxus brevifolia Nutt., andAbies lasiocarpa were examined but no Tholurna was found on them.
Species growing associated with the Tholurna included Alectoria frenionlii Tuck.,A. sarmentosa (Ach.) Ach., Hypogymnia imshaugii Krog, Parmelia exasperatula Nyl.,and Platismatia glauca (L.) W. Culb. & C. Culb.