BIVERTICILLATA-SYMMETRICA (323 



iisuall}^ longer than on Czapek, up to 200 or 2o0ai in length; penicilli as 

 described above. 



Species description centered upon XRRL 1050, received in 1930 as a 

 soil isolate from M. B. Morrow, University of Texas; and XRRL 2131, 

 received from Professor William H. Weston, Harvard Universit}^, as an 

 unidentified strain isolated from materiel exposed in Florida. The species 

 is represented by two additional strains, also isolated in the Florida ex- 

 posure tests. 



Superficially^ there is little cultural basis for separating this species 

 from some of the lightl}^ pigmented strains of Penicillium funiculosum. 

 Structural details, however, differ markedly. The penicilli are shorter, 

 wider, and relatively more compact; the metulae and sterigmata are shorter 

 and relatively heavier; and the conidia are globose and strongly echinulate. 

 These forms are clearly distinct from typical strains of P. funiculosum 

 Thom, or any of its recognized variants and warrant recognition as a sepa- 

 rate species. Except for the absence of columns of conidial chains, the 

 above strains seem to agree reasonably well with Peyronel's meager de- 

 scription of P. verruculosum (isolated from air in Northern Italy), hence 

 they are assigned to this species. 



Culturally the species, as presented here, is very distinct from Penicillium 

 aculeatum Raper and Fennell, but details of structure show much in com- 

 mon in the two species. Penicillium verruculosum as described above would 

 probably have been included in Thom's ''P. luteum series, non-ascosporic," 

 in the broad sense that this usage was employed in his Monograph (1930), 

 since it is characterized by rather rapidly growing colonies with a strong 

 admixture of yellow, sterile mycelia and dark green conidial heads to give 

 a pronounced yellow-green effect. 



NRRL 2135, received from Professor W. H. Weston, as an isolate from 

 exposed fabrics in Florida, is believed to represent an extreme variant of 

 the species characterized by some nutrient deficiency, possibly an absence 

 or inadequacy of invertase. It differs from the typical strains cited above 

 primarily in producing very limited and restricted colonies on Czapek's 

 solution and steep agars which do not exceed 2 to 3 mm. in diameter in two 

 to three weeks. Colonies on malt agar are broadly spreading, heavily 

 sporing, dark yellow-green, and are essentially typical of the species. Peni- 

 cilli are characteristic of the species and produce globose, strongly rough- 

 ened conidia. 



Penicillium islandicum Sopp, in Monogr., pp. 161-164, Taf. XVH, fig. 122; 

 Taf. XXIII, figs. 25 and 26. 1912. Thom, The Penicillia, 



pp. 466-467. 1930. 



Colonies on Czapek's solution agar (Col. PI. X) slow-growing, attaining 

 a diameter of 2.5 to 3.0 or 3.5 cm. in 2 weeks at room temperature, often 



