HYPOCREALES 



235 



differentiated to special, more or less developed conidiophores. Often 

 they are embedded in slimy masses which are called pionotes. In 

 Nectria oropensoides and N. Peziza, the conidia adhere to the conidio- 

 phores in small slimy heads; in luxuriant cultures, the conidiophores 

 unite to coremia surrounded by capitate spore masses (Fig. 150, K). 

 Under certain cultural conditions, the conidiophores change to flat, 

 pulvinate stromata, or sporodochia (Fig. 150, F) ; these suggest, morpholo- 

 gically, horizontally broadened coremia and often consist of thick- 

 walled, plectenchymatic stromata and conidiophores radiating from them. 



Fig. 151. — Conidial types of the Fusarium group. 1. F. Solani. 2. F. subalatum.. 

 3. F. discolor. 4. F. gibbosum. 5. F. didymum. 6. F. Willkomii. (X 070; after Appel 

 and Wollcnweber, 1913.) 



In Nectria and Pleonectria, these sporodochia develop to pulvinate or 

 gibbous fructifications often of characteristic form (Fig. 150, A and B); 

 these imperfect forms were formerly classified in the genus Tubercularia 

 of the Fungi Imperfecta Exceptionally, the conidiophores are formed in 

 the interior of irregular winding cavities (Fig. 150, H) instead of superfi- 

 cially; thus, in Nectria sinopica on hard stems of ivy, the orange- red 

 mycelium, with suitable food, collects in knots which in about two months 

 are differentiated to pycnia and at maturity forces white coils of very 

 small, hyaline conidia from the ostioles. 



For practical purposes, the conidia may be divided into macro- 

 and microconidia; both types are only the two extremes of the same 



