THE ORDERS OF FUNGI 57 



Class Ascomycetes 



21. Asci not aggregated in ascocarps, that is, naked and formed 



singly or in loose clusters Subclass Hemiascomycetes 22 



21. Asci aggregated, enclosed in well-developed ascocarps 



Subclass Euascomycetes 23 

 22. Saprobic, ascus formed directly from zygote, mycelium not 

 well developed, cells usually bud 



Order Endomycetales (Saccharomycetales) 

 22. Strictly parasitic on vascular plants, apical cells become asci, 

 mycelium not well developed, budding very common 



Order Taphrinales (Exoascales) 

 23. Ascocarps lack definite ostioles, hence are cleistothecia 24 

 24. Asci irregularly arranged Plectomycetes 25 



25. Stroma lacking, asci filling interior of ascocarp 



Order Eurotiales (Aspergillales) 

 25. Stroma present, asci borne singly in locules 



Order Myriangiales 

 24. Asci regularly arranged Order Erysiphales (Perisporiales) 

 23. Ascocarps provided with ostioles or cupulate, asci ar- 

 ranged in parallel series 26 

 26. Ascocarps with neck-like ostioles, hence perithecia 27 

 27. Perithecia borne on a receptacle, minute parasites 



on insects and arachnids Order Laboulbeniales 



27. Perithecia not borne on a receptacle 28 



28. Perithecia globose, ostiole typically circular in 

 cross-section Pyrenomycetes 29 



29. Perithecia borne singly or in a stroma, 

 black or dark colored 30 



30. Perithecia provided with definite wall 



Order Sphaeriales 

 30. Differentiated perithecial walls lacking, 

 asci borne in stromatic locules 



Order Dothideales 

 29. Perithecia borne singly or in a stroma but 

 always bright colored— red, yellow, purple 



Order Hypocreales 

 28. Perithecia elongated with a slit-like ostiole 



Order Hysteriales 

 28. Perithecia dimidiate, opening with a pore or 

 irregular rift Order Hemisphaeriales 



26. Ascocarps wide open, discoid, hence apothecia 



Discomycetes 31 

 31. Asci inoperculate 32 



32. Apothecia superficial, mostly small, fleshy, or 



waxy Order Helotiales 



32. Apothecia innate, mostly small, carbonaceous 



Order Phacidiales 



