APPENDIX VII 703 



B. Sterigmata branched. Aspergillus albus. 

 II. Colored spores. 



A. Spores yellowisli-green, bluish-green, grayish-green, green. 



1. Sterigmata unbranched. 

 (a)Perithecia produced readily. 



1. Perithecia not imbedded, naked. A. herbariorum. 



2. Imbedded perithecia. 



With slightly swollen conidiophore tips, sterigmata club-shaped, later- 

 ally placed. A. clavaius. 



With hemispheric conidiophore tips, sterigmata terminal. A.fumigatus. 

 (b) Perithecia unknown. 



1. With large conidiophore tip, elongate 80 to ioom by 500 to Soo/x. A. 

 giganteus. 



2. With smaller conidiophore, end spheric, or hemispheric. 

 With rough worty conidiophore. A . flavus. 



With smoother conidiophore. A. oryzea. 



2. Sterigmata branched. 



(a) With rusty-brown myceUum. A. versicolor. 



(b) Mycelium not rusty-brown. 



End of conidiophore, club-shaped with lateral and terminal sterigmata. 

 A. pseudoclavatus. 

 End of conidiophore hemispheric with terminal sterigmata. A . nidulans. 



B. With black, or dark-brown conidiospores. 



1. Sterigmata unbranched. A. calyptratiis. 



2. Sterigmata branched. A. niger. 



C. With reddish-brown, yellowish-brown, or yellow conidiospores. 

 Sterigmata unbranched, spores coffee-brown. A. Wenlii. 

 Sterigmata branched, spores yellow-brown. A. ochraceus. 



The genus Penicillium is closely related to the genus Citroniyces, which includes 

 fungi causing citric acid fermentation in sugar media and which has a single whorl 

 of conidia-bearing cells (sterigmata) at the tip of the conidiophore. All of the 

 fungi with the penicillate type of fructification are grouped together in the form — 

 genus Penicilliiiin. The small and delicate conidiophore differs from that of Asper- 

 gillus in being divided into a row of short cells by transverse septae. The conidio- 

 phores are branched and the upright branches bear the sterigmata as tufts of termin- 

 ally disposed secondary branches. The conidiospores are pinched off from the ste- 

 rigma and are arranged in chains. The whole inflorescence suggests a whisk, or a 

 broom. The spores are of various shapes and sizes from spheric to ellipsoidal. 

 Some have smooth walls, others are roughened. Several species show the tendency 

 to form coremia (coremium), which are tufted forms of inflorescence. Four, or 

 five, species are known to produce perithecia and ascospores, so that no satisfactory 

 key can be based on perithecial and ascosporic characters. The number of species 

 which are associated with the ripening of cheeses, or which produce decay in fruits 

 of various kinds is about six or seven. The species usually designated as Penicillium 

 glancnm and P. crustacenm are included in the most recent paper by Thom under 



