PENICILLIUM AVELLANEUM, A NEW 
ASCUS-PRODUCING SPECIES^ 
Charles Thom and G. W. Turesson 
Ascus production by species of Penicillium is not common. 
The observations of certain species by Brefeld,^ Morini^and West- 
ling* have never been repeated by other workers, some of whom 
have watched thousands of cultures in the hope of finding one 
of these forms. On the other hand, P. liitemn ZukaP is a mem- 
ber of a widely distributed group,® some members of which have 
been found repeatedly, while the ascus-producing form is not 
uncommon. Ascus production in this species is not dependent 
upon special methods of culture. Another species has now been 
found by one of us (Turesson) in cultures from the faeces of 
a bear in the Zoological Garden, at Seattle, Washington. In 
this form as in P. luteum, the asci are produced in almost all of 
the media regularly used. The time required varies from six 
weeks to perhaps three months. Its morphology relates it to P. 
luteum and to the ascus-producing forms of Aspergillus. 
Penicillium avellaneum sp. nov. Thom & Turesson. Colonies 
upon Czapek’s solution agar, broadly spreading, slightly floccose, 
in conidial areas becoming persistently avellaneous (Ridgeway 
XL, 17' " 6), producing perithecia slowly during a period of sev- 
eral weeks with the gradual development of aerial hyphae colored 
Indian-red in the perithecial areas ; reverse and agar becoming 
Indian-red (Ridgway XXVII, 3" K) ; conidiophores up to 400 /x 
long by 3 to 5 4 in diameter, bearing conidial fructifications up to 
1 Published by permission of the Secretary of Agriculture. 
2 Brefeld, O. Bot. Unters, iiber Schimmelpilze, Heft 2. 1874. 
3 Morini, Fausto. Sulla forma ascofora de Penicillium candidum, Link. 
Malpighia, anno 2. fascicule 5/6 pp. 224-234. Messina, 1888. 
* Westling, R. Svensk Botanisk Tidskrift, Bd. 4 (1910), Heft 2, pp. 139— 
144. 
5 Zukal. Sitz. d. Kais. Akad. d. Wissensch. in Wien, Math. Naturw. Cl., 
XCVIII, p. 561, 1889. 
« Thom. C. The Penicillium luteum-purpurogenum group, Mvcologia, 
Vol. VII (1915). no. 3, pp. 134-142. 
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