176 A MANUAL OF THE PENICILLIA 



Penicillium columnare Thom (The Penicillia, pp. 214-215. 1930) was described as 

 a thinly growing species which produced columnar masses of dark green conidia up 

 to 100 to 150m in length; conidiophores were short, about 20 to 50m by 2.0 to 2.5 or 3.0m 

 and were borne on hyphae mostly submerged; conidia were about 3.0m, faintly punc- 

 tate or possibly spinulose. The strain, or strains (it was repeatedly seen during one 

 summer's work) when isolated were regarded as meriting species recognition, but 

 were quickly lost from the collection. In investigations since that time, strains 

 otherwise normal have occasionally been isolated which suffer from some nutritional 

 deficiency and which on Czapek's solution agar produce very thin growing colonies. 

 It is believed that P. columnare probably represented such a strain in the P. fre- 

 quentans series. 



Penicillium flavi-dorsinn Biourge (Monograph, La Cellule 33: fasc. 1, pp. 290-291; 

 Col. PI. VIII and PI. XIII, fig. 73. 1923) is regarded as closely approximating, if not 

 duplicating, P . frequentans Westling. Conidiophores and sterigmata were described 

 by Biourge as having walls squamulose and echinulate-squamulose respectively. 

 Thom, studying the type culture (now NRRL 774), subsequently noted some mark- 

 ings on a part of the coiiidiophore walls but failed to recognize this as an unusual or 

 distinguishing character. Conidia were reported as subglobose, about 3.0 to 3.5m 

 in diameter, and with a trace of pitting or echinulation. Current study of the above 

 strain and one from the Centraalbureau, Baarn, (listed as Biourge's, but darker green 

 and heavier sporing than NRRL 774) confirms Thom's earlier observations, but fails 

 to provide any basis for species separation. 



Penicillium fluitans Tiegs, in Ber. deut. bot. Gesellsch. 37: 499-501. 1919. The 

 description cites no morphology differing from members of the great P. frequentans 

 series. Its chief interest lies in its unique occurrence upon or in waste water, from a 

 munitions factory, acidified with nitric acid. Vegetative mycelium (without conidia) 

 was reported in solutions containing 0.25X nitric acid. The organism was reported 

 as present in pure culture under the acid conditions described and to be displaced by 

 other species when the water was neutralized. No closer identification is possible 



Penicillium glabrum (Wehmer) Westling, in Arkiv for Botanik 11: No. 1. pp. 131- 

 132, fig. 77. 1911; also, Thom, The Penicillia, pp. 220-221. 1930. Syn: Citromijces 

 glaber Wehmer, in Beitr. z. Kennt. einh., Pilze I, p. 24; Taf . I, figs. 14-24. 1893- This 

 species is of interest primarily from an historical point of view. Wehmer described 

 two species of Citromyces , namely C. glaber and C. pfefferianus , in connection with 

 his studies on citric acid production, but failed to differentiate adequately between 

 them. Several years later, in a personal interview with Thom, he declined to identify 

 either species with certaintj'^ to individual strains. The name C. glaber Wehmer and 

 P. glabrum (Wehmer) Westling have been looselj' and widely used since their incep- 

 tion, especially in biochemical literature, with the result that they now have even 

 less meaning than as used by Wehmer. About all that can be said is that they usually 

 represent strains of the P. frequentans series. A strain was received from the Cen- 

 traalbureau, Baarn, in August 1946 bearing Westling's name which is said to have 

 come from Thom in 1914. It apparently represents a culture received from Westling 

 under this name and passed on to the Centraalbureau shortly thereafter. Colonies 

 on Czapck are rapidly growing, velvety, deep dark green in color with reverse in 

 orange-brown toward violet-red shades; conidiophores smooth or finely roughened; 

 and conidia in compact columns, globose to subglobose, about 3.0m with walls some- 

 what echinulate. The culture should be regarded as typical P. frequentans , 



