1920] 
. BURT—THELEPHORACEAE OF NORTH AMERICA. XII 187 
layer becoming zonateand con- 
taining numerous colored cys- 
tidia having more or less the 
appearance of colored conduct- 
ing organs; cystidia colored, 
cylindrie, obtuse, even, rough- 
walled or more or less incrusted, 
90-150 X 6-8 u, protruding upto 
60 u; spores hyaline, even, flat- 
tened on one side, 9-13 4—5 u. 
Resupinate specimens 2-8 X 
2-5 cm., reflexed margin 3-8 
mm. broad. : Fig. 28. ©. abietinum. Section X 
On wood and logs of Abies 68; crust-like zone, z; hymenium con- 
and Pinus. New Hampshire taining colored cystidia, h; cystidium, c, 
to Washington and in Europe. 3nd spores, s, X 488. 
June to October. Rare. 
S. abietinum usually occurs resupinate, but its thick, separable, 
felty fructifications are suggestive of a resupinate Stereum, and 
this view is confirmed by the presence of the intermediate layer 
when radial, vertical sections are examined. The cinereous, 
pruinose surface of the hymenium due, however, to whitish, 
cobwebby filaments rather than powdery grains, is highly char- 
acteristic and shared only by the western S. rugisporum, as 
are also the colored cylindric cystidia. S. rugisporum is sepa- 
rated by its odor of anise, much thicker and more broadly 
reflexed pilei, and presence in occasional collections of colored 
spores imbedded in the deeper zones of the hymenium. 
I have included Hymenochaete fimbriata among the synonyms 
of S. abietinum, but it may prove to belong with S. rugisporum 
instead. 
Specimens examined: 
Exsiccati: de Thümen, Myc. Univ., 1107. 
Norway: Christiania, M. N. Blytt, type of Stereum glaucescens 
(in Herb. Fries). 
Sweden: Stockholm, L. Romell, 29; Upsala, C. G. Lloyd, 08521 
(in Lloyd Herb. and Mo. Bot. Gard. Herb., 55497). 
Finland: Mustiala, P. A. Karsten, in de Thümen, Mye. Univ., 
1107. 
Ld 
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