124 C. D. Sherbakoff 



Page 

 ii. Microconidia typically present, usually spindle-shaped, non- to 



three-septate Section Arthrosporiella 161 



j. Six- to seven-septate conidia typically present, at least in pseudo- 

 pionnotal stage 

 k. Distinct sporodochia present 



1. Substratum and aerial mycelium near it typically of carmine 



hues, causal layer of aerial mycelium pink F. biforme 166 



11. Substratum of a clay color, aerial mycelium white 



F. diver sisporum 161 

 kk. No conspicuous sporodochia, fruiting layer on moist media 



commonly in form of a pseudopionnotes F. anguioides 189 



jj. Six- to seven-septate conidia absent F. arthrosporiaides 175 



hh. Chlamydospores present, typically intercalary only 



i. Microconidia present, pyriform Section Sporotrichiella 183 



F. sporotrichioides 183 



ii. Microconidia absent or not pyriform Section Ferruginosum 186 



j. Typical macroconidia of about equal diameter for a considerable 

 length, or not prominently broader in the middle, in some cases 

 approaching the subulatum type, much curved 

 k. Chlamydospores typically only in mycelium 



1. Chlamydospores sparse, never in masses nor in long chains . . 



F. arcuosporum 186 

 11. Chlamydospores typically abundant, commonly in masses of 



long chains and in clusters F. ferruginosum 190 



kk. Chlamydospores also in conidia or in conidia only 



F. sanguineum 193 

 jj. Macroconidia typically noticeably broader at the middle, not 



very pointed at the apex, not much curved F. bullatum 198 



gg. Conidia typically three-septate; typical color of substratum vinaceous 

 red to purplish vinaceous; terminal and intercalary chlamydospores 



present Section Elegans 202 



h. Conidiophores simple or only slightly branched 



i. Average macroconidia 36 M long F. orthoceras 202 



ii. Average macroconidia 45.6 M long F. angustum 203 



hh. Conidiophores typically much branched 



i. In plate cultures on neutral potato agar producing exposed and 

 distinct pseudopionnotes 

 j. Color of the pseudopionnotes vinaceous red.F. redolens var. Solani 205 



jj. Color of the pseudopionnotes vinaceous purple F. lutulatum 209 



ii. No exposed and distinct pseudopionnotes in potato agar plate 

 cultures 



j. Macroconidia typically somewhat broader toward apex 



F. sclerotioides 214 

 jj. Macroconidia typically not broader toward apex. . F. oxysporum 220 

 *e. Conidia with more or less abruptly attenuated apex, rounded or papillate 

 f . Substratum typically (on glucose agar) carmine red. The color may be 



yellowish, but never gray, green, nor blue Section Discolor 228 



g. Conidia non- to three-septate, rounded at both ends, of common type, 



numerous (those of discolor type usually only few) . F. trichothecioides 229 

 gg. Discolor type of conidia common, "and nearly th« only type present 

 h. Conidial masses pale cream to pale pink in color, aerial mycelium well 



developed and nearly white F. subpallidum 230 



