88 



DOTHIDEALES 



(y) Spores muriform, hyaline; paraphyses 

 branched and united 

 y. Paraphyses dissolving or lacking 

 (x) Paraphyses dissolving in mucus; 



thallus corticate 

 m. Spores 1-celled, hyaline 

 n. Spores mostly 2-celled 

 (m) Spores hyaline 

 (n) Spores dark 

 o. Spores muriform, hyaline to brown- 

 ish; asci 1-2-spored 

 (y) Paraphyses lacking; thallus not cor- 

 ticate 



(2) Algae Trentepohlia; spores 1-celled, hya- 



line 



(3) Algae Prasiola; spores 1-celled, hyaline 



c. Thallus fruticulose, branched; algae Pleuro- 

 coccus 



(1) Spores 2-celled, hyaline 



(2) Spores muriform, dark 



B. Perithecia in a stroma (Cfr. Pertusariae, p. 128) 



1. Perithecia erect, with separate ostioles 



a. Spores x-celled 



(1) Spores hyaline 



(2) Spores dark 



b. Spores muriform 



(1) Spores hyaline; asci 2-8-spored 



(2) Spores dark 



c. Spores acicular to filiform, hyaline 



2. Perithecia oblique or horizontal, the necks long 



and with a common pore; valsoid 



a. Spores x-celled 



(1) Spores hyaline 



(2) Spores dark 



b. Spores muriform 



(1) Spores hyaline 



(2) Spores dark 



C. Perithecia sunken in stroma-like warts; horizontal 



thallus lacking; asci many-spored; spores 

 1-celled, hyaline 



Psoroglaena 71 



Dermatocarpum 71; 18 



Placidiopsis 72 

 Heterocarpum 72 



Agonimia 73 



Normandina 71 



Lepolichen 81 

 Mastodia 92 



Nylanderiella 73 

 Pyrenothamnia 74 



Subfamily Trypetheliae 81 



Trypethelium 83 ; 18 

 Melanotheca 82 



Laurera 83 

 Bottaria 83 

 Tomasiella 82 



Subfamily Astrotheliae 85 



Astrothelium 86 

 Pyrenastrum 86 



Cryptothelium 86 

 Parmentaria 87 



Thelocarpum 213 



Order 9. DOTHIDEALES 



Perithecia composite in a stroma, without a wall distinct from the stromal tissue 

 and hence reduced to polyascous locules, or irregularly stromoid or discoid with 

 monascous loculiform hollows; the stroma immersed and often forming a clypeus, 

 erumpent, or superficial and usually with a hypostrorna; asci many, more or less 

 cylindric and often with true paraphyses in Dothideaceae, or single in the hollows, 

 globose to ovoid, rarely cylindric, separated by stromal tissue or paraphysoids 

 in Myriangiaceae. 



This order is not regarded as a natural one, nor are the two families considered 

 to be phylogentically related. While the presence of a locule affords the warrant 



