628 A MANUAL OF THE PENICILLIA 



ing easily, with central area 1.0 to 1.5 cm. in diameter, raised, bearing few 

 conidial heads but surrounded by a thinner plane marginal zone producing 

 abundant conidial structures in a loose mycelial network, in dull yellow- 

 green shades near tea green or pea green (Ridgway, PI. XL VII), occasional 

 strains lacking the prominent thin margins, but showing the entire colony 

 area felted, producing limited numbers of conidial structures and consider- 

 able sterile mycelium throughout; exudate fairly abundant, mostly as mi- 

 croscopic droplets adherent to the mycelium; odor distinct, rather pleasant; 

 reverse in brownish orange shades, with the green of conidial areas showing 

 through in marginal areas; conidiophores arising from a loose netw^ork of 

 short, much-branched aerial hyphae, usually about 20 to 35m by 2.5 to 

 3.0m, rarely 50/x or more, smooth-walled; penicilli very compact, typically 

 biverticillate and symmetrical (fig. 161D), consisting of 10 to 12 metulae 

 borne on the terminal portion of the vesicular apices of the conidiophores; 

 metulae 8 to 10/i bj^ 1.8 to 2.2/x, with outer metulae incurved, tending to 

 become parallel with the main axis of the conidiophores; sterigmata typical, 

 acuminate, parallel, occurring in crowded clusters of 5 to 7, 8 to 9m by 1.5 

 to 1.8m, producing conidia in closely adherent chains which consistently 

 produce conical to pyramidial masses up to.l50M long (fig. 161C); conidia 

 subglobose to elliptical, 2.5 to 3.0m by 2.2 to 2.8m, smooth when young, 

 becoming heavy-walled and irregularly roughened when mature, dark olive 

 green in mass, chains adherent and the masses of conidia retaining their 

 conical shape even in liquid mounts. 



Colonies on steep agar rapidly growing, 5.0 to 5.5 cm. in 12 to 14 days 

 at room temperature, plane, velvety in appearance but consisting of a loose 

 network of dwarfed aerial hyphae, heavily sporing throughout in dull 

 yellow-green shades near slate olive (R., PI. XL VII), surface of colonies 

 overgrown to a greater or lesser degree by sterile encrusted yellow mycelium, 

 becoming conspicuous in some strains; exudate limited to abundant, in 

 small droplets, clear to very light yellow; odor as on Czapek; reverse in 

 orange or red-brown shades becoming almost black in older areas; details 

 of penicilli as described on Czapek, but with masses of conidia less con- 

 spicuously cone-shaped and up to 200m in length. 



Colonies on malt extract agar 4.5 to 5.0 cm. in diameter in 12 to 14 days 

 (fig. 161B), 1 to 2 mm. deep, surface uneven from irregular tufts of funicu- 

 lose encrusted hyphae, fairly heavily sporing, in yellow-green shades near 

 vetiver to Andover green (R., PI. XLVII); exudate limited in amount, 

 evaporating to leave pits in the colony surface; odor fragrant, faintly sug- 

 gestive of apples; reverse uncolored or showing very slight orange tints; 

 microscopic details as on Czapek. 



Species description centered upon NRRL 1051 from the Thom Collection 

 as an unidentified culture. Duplicated by NRRL 1071 received in 1937 



