The Origin of ‘ Golden 5 Oak. 
BY 
HELEN STUART WILLIAMSON. 
(.Imperial College of Science and Technology.') 
With Plate X and four Figures in the Text. 
T HE specimen of oak which was the origin of this investigation was sent 
to the Timber Department of the Imperial College by Dr. Butler. 
The wood showed yellow coloration externally and extending internally 
for two or three millimetres. The specimen was seasoned heartwood of 
Quercus robur . Externally there appeared to be rather fluffy mycelium, 
some black sporangia, and small round yellow bodies. 
Methods of Isolation of the Fungus. 
Three fungi were isolated from the surface of the wood, viz. a species 
of Aspergillus, Penicillium lutemn forming yellow ascocarps, and a new 
fungus, with yellow conidia in long chains, which has been named Eidanda 
catenulata ( 4 ). Dilution plates of potato extract agar, inoculated from a 
needle drawn across the surface, gave a species of Aspergillus, one colony 
of Penicillium luteum , and Eidamia catenulata in the first dilution, with 
only the last-named fungus in the second and third dilution plates. This 
fungus is characterized by its very long chains of yellow conidia. The 
conidia are oval and measure 3-5 to 5/a by 2-5 to 3-5 y, whereas those of 
Penicillium luteum ( 7 , 7 a) are rounder and measure 2-4 to 2-8 y by i-6 
to 2-4 y. 
In all the cultures of Eidamia catenulata obtained in this way, hyphae 
bearing hyaline spores also occurred, so single spore cultures were obtained 
both from the conidia and from the hyaline spores. In each case both 
types of spores were produced on the resulting growth, and later examina¬ 
tion revealed the same hypha bearing both conidiophores and single hyaline 
spores on branches. In this way it was proved that Eidamia catenulata 
possesses two types of spores. 
In order to isolate from inside the wood the fungus causing the yellow 
coloration, a piece three inches in length was sawn from the original board 
[Annals of Botany, Vol. XXXVII. No. CXLVII. July, 1923.] 
