BIVERTICILLATA-SYMMETRICA 599 



August 1945, from Dr. Ralph Emerson as an isolate from retting guayule 

 shrub, Salinas, California. Both of these cultures produce abundant peri- 

 thecia upon most substrata and are regarded as wholl}^ typical of the species. 

 The species is also represented by XRRL 1005 (Thom, Xo. 4401) received 

 in 1930 as an isolate from cereal products, Guatemala City, Guatemala. 

 ^\^len first isolated this culture produced abundant perithecia and asco- 

 spores and was cited by Thom in his Monograph (1930, p. 447), but the 

 ascosporic phase has been lost during the ensuing years. The strain was 

 sent to the Centraalbureau by Thom in 1930 and was returned to us for the 

 present study in February 1946. Their substrain is now predominantly 

 conidial but when cultivated upon corn meal agar still produces occasional 

 small perithecia which develop limited numbers of typical asci and asco- 

 spores. It is included in our Collection as NRRL 2109. Other strains 

 have been examined from Puerto Rico, China, Panama, and various sta- 

 tions in the United States. The species is not abundant but appears to 

 be widely distributed. Members of this species, even more than most 

 other members of the Penicillium luteum series, tend to lose their capacity 

 to produce perithecia when long maintained in artificial culture. 



In their original description, Thom and Turesson described and figured 

 the perithecium as bounded by a definite and continuous cellular wall or 

 peridium, one cell in thickness. The ascosporic strains examined in the 

 present study fail to develop this specialized structure and show instead 

 a closely interwoven mycelial covering not markedly different from that 

 seen in Penicillium vermiculatum Dangeard, P. sfipitafum Thom, P. striatum 

 Raper and Fennell, and others. Penicillium avellaneum is beheved to be 

 properly assigned in the P. luteum series upon the basis of its perithecial 

 structures. It differs from other members of the series by producing (1) 

 coarse hyphae in greater or less abundance which develop reddish purple 

 colors near Indian red, (2) ascospores with heavy, pitted walls, and (3) 

 conidial structures which, although often biverticillatety-symmetrical in 

 pattern, differ substantially from the typical penicilh of this group. Metu- 

 lae are often produced in considerable numbers, up to 8 or 10 or more, and 

 sterigmata fail to show the lanceolate pattern characteristic of this section 

 of the genus. Upon the basis of the conidial structures alone, one might be 

 tempted to assign this species to the Brevi-Compacta series (see p. 404). 



Penicillium ingelheimense van Beyma, in Antonie van Leeuwenhoek J. Microbiol. 

 Serol. 8: 109. 1942. This species, as it is represented in our cultures upon different 

 substrata, appears to be an unusually coarse strain of P. avellaneum T. and T. Co- 

 nidiophores are commonly 500m or more in length and in terminal areas may reach a 

 diameter of 7 to 8/u. In liquid mounts walls appear smooth but when examined dry 

 show some evidence of roughening (adherent material ?) . The penicilli are unusually 

 large and the number of metulae present in some structures is estimated to range up 



