A literature survey is given of the five European honey mushrooms Armillaria mellea, A. borealis, A. bulbosa, A. eepistipes, and A. obseura (syn, A. ostoyae) (eorresponding respectively to KORHONEN' intersterile groups D, A, E, B, and C); two forms oi A. eepistipes are discussed: tbe tiny A. cepistipes i. cepistipes from Czechoslovakia and West Germany and the more eommon A. eepistipes i. pseudobulbosa Romagnesi et Marxmuller, Nomenclature, geographical distribution, hosts, sotne characteristics, and practical importance (ineluding pathogenicity) are treated.

Field studies of damage and mortality were carried out through 16 years in six young plantations, mostly of Pinus contorta, but also P. sylvestris and P. sibirica. Differences between pine species, P. contorta provenances, sites, and soil treatments are reported and discussed, as are influences of environment, climatic conditions, snow cover, and nutrient deficiency. Gremmeniella abietina was by far the most important cause of mortality; there were great differences between the sites as to development and seriousness. Other important causes of mortality and damage were Phacidium infestans, elk (Alces alces L.), voles, and snow pressure.

Ascocoryne spp. (A. cylichnium and A. cf. sarcoides) were found in 48 % of 262 60‐year‐old Picea abies stems. They were isolated with increasing frequency towards the pith from the lower 2‐3 m, more often from thicker than from thinner stems. Neobulgaria premnophila was present in 10 % of the stems, more evenly distributed, and with no difference in occurrence between thicker and thinner stems. Nectria fuckeliana was situated at random in 8 % of the trees.

Melampsoridium betulinum from Betula verrueosa was found able in infeetion experiments to infect Alnus barbata, A. eordata, A. glutinosa, A. ineana, A. orientalis, A. rhombifola, and A. viridis. Melampsoridium etilleetions on Alnus spp. in Norway, Finland, Seotl.md, and Ireland were identified with M. betulinum. Alnus species seem to be poorer hosts for M. betulinum than the Betula species. M. alni is eonspeeifie with M. betulinum. IntroductionA Melampsoridium sp. was found on leaves of plants of Alnus glutinosa (L.) Gaertn. in a nursery at the Agricultural University of Norway at As on 2 October 1972 by the student Peder GJERDRLFM. The plants were growing in a row beside a row of plants of Betula verrueosa Ehrh. heavily infected by Melampsoridium betulinum Kleb. Uredinia and telia were found on both hosts, but most abundantly on the birches. The alders might have been infected from the birches.Previous authors have based discrimination between Melampsoridium species on host species, on length of ostiolar cells m the uredinial peridium, and on size and echinulation of the urediniospores. In the present paper discussions on the morphology are based on the same characters.Literature data on Melampsoridium on Alnus, report on infection experiments, and report on examination of lierbarium specimens are given. Earlier descriptions and recordsAccording to the literature, two Melampsoridium species are described from Alnus {M. alni and M. hiratsukanum) and one frotn Betula (M. betulinum).Melampsoridium alni Diet. THUMEN (1878) described Melampsora alni on Alnus viridis (Chaix) DC. of the subgenus Alnaster (Spach) Endl., from the Sayan mountains in Siberia; only uredinia were described; the urediniospores were found to be cyltndrtcal-clavate, cylindrical, or oblong, subverruculous or nearly smooth, 40 (im long. TRANZSCHEL (1895) described both uredinia and telia also on A. viridis from the Sayan mountains; for the urediniospores he gave the measures 28-42X 10-15 nm. DIETEL (1900), referring to THUMEN, transferred the fungus to the genus Melampsoridium mentioning that it had been found on A. viridis from Ural to Japan.In other papers, from 1936 and later, concerning M. alni in Asia similar measures for the urediniospores were given: 27-47x9-18 | xm (HIRATSUKA 1936(HIRATSUKA , 1958, 39.6x11.2 \im U. S. Gopyright Glearanee Genter Gode Statement: 0300-1237/8f / 1 lOf /0077 $ 02.50/0 Eur.

Various pine species and provenances attacked by Scleroderris lagerbergii are reviewed with respect to their resistance. Pinus aristata is a new host. Introduced pine species may often become attacked if the ecological conditions in the new localities are different from those occurring under natural circumstances. Usually local provenances are more resistant than southern ones, but less resistant than more northern ones.