70 NORTH AMERICAN FLORA [V01.UME 7 



Illustrations: Ann. Bot.6: pi. 2 J. 72-74 ; Bull. Conn. Geol. Nat. Hist. Surv. S\ f. 19,22,29. 

 ExsiCCATi: Rab.-Wint.-Paz. Fun^i 'Q,wx.3S02; Seym. & Earle, Kcon. Fungi C^, C13. 



6. Doassansia occulta (Hoffm.) Cornu ; Farl. Trans. Ottawa Field 



Nat. Club 2 : 129. 1884. 



Sclerohum occuUum Hoffm. Ic. Anal. Fung. 67. 1863. 

 Doassansiopsis occulta Dietel, in K. &l P. Nat. Pfl. li**: 21, 1897. 



Sori in ovaries, causing them to become considerably swollen, ovate, olive-green to 

 reddish-brown ; spore-balls situated in the endocarp, consisting of a distinct cortex within 

 which is a single layer of fertile cells surrounding a central mass of parenchymatous cells, 

 ellipsoidal to spherical, often irregular, 100-160 fJ. in length ; cortical cells polyhedral or 

 more elongate tangentially, 8-10 // in length ; spores adhering rather firmly, about 10-12 (i 

 in length. 



On Zannichelliaceae : 



Potamogeton Nnitallii {P. pennsylvantcus) , Connecticut, New York. 



Potamogeton sp., Illinois, Kansas. 

 Type locality : Germany, on Potamogeton sp. 



Distribution : Connecticut, New York, Illinois, and Kansas ; also in Ktirope. 

 Illustrations : Hoffm. loc. cit. pi. 16 (J),/. 1-9 ; Ann. Bot. 6 : pi. l,f. 43-50, pi. 2,f. 79. 

 Exsiccati : Rab.-Wint.-Paz. Fungi Eur. 3801. 



Doassansia occulta Farlowii (Cornu) Setch. Proc. Am. Acad. 26: 17. 1891. Doassansia Far- 

 lowii Cornu, Ann. Sci. Nat. VI. 15 : 287. 1883. Sori and spore-balls as in the species ; cortical cells 

 smaller ; spores chiefly oblong, about 16 m- X 3^ M-. On Zananichelliceae : Potamogeton natans^ 

 Canada. Potam^ogeion Nuitallii (P. p ennsylv anions') , Vermont. Potamogeton perfoliatus Rich- 

 ardsonii {P. perfoliatus lanceolatus) , Canada. Potamogeton pusillus, Canada. Potamogeton 

 Vaseyi, Canada. Illustrations : Ann Sci. Nat. VI. 15 : pi. 16, f. 5, 6 ; Ann. Bot. 6 : pi. 2,f. 78. 



7. Doassansia Martianoffiana (Thiim.) Schrot. Krypt. Fl. Schles. 



3' : 287. 1887. 



Protomyces Martianoffianus Thiim. Bull. Soc. Nat. Mosc. 53^ : 207. 1878. 

 Doassansiopsis Martianoffiana Dietel, in E- & P. Nat. Pfl. 1'** : 21, 1897. 



Sori in leaves, thin, forming at first yellowish but eventually reddish-brown discolora- 

 tions, distinct as small circular spots or more usually merged into indefinite areas often cover- 

 ing greater surface of leaf ; spore-balls situated in the spongy parenchyma, consisting of a 

 distinct cortex surrounding a single layer of fertile cells within which is a central mass of 

 parenchymatous cells, subspherical or spherical, 100-160 (j. in diameter ; cortical cells brown, 

 small, irregularly polyhedral or tangentially elongate, about 8-11 /Ci ; spores slightly tinted, 

 polyhedral or elongate radially, chiefly 10-16 /i in length. 



On Zannichelliaceae : 



Potam-ogeton natans, Massachusetts. 



Potamogeton sp., Connecticut, Illinois, New York, Washington, Wisconsin ; Canada. 

 T.YPE LOCALITY : Minusiusk, Siberia, on Potamogeton natans. 



Distribution : New England to Wisconsin and Illinois ; Canada ; also in Europe and Asia. 

 Illustrations: Ann. Bot. 6: pi. 2,f. 80; E- & P- Nat. Pfl. l^**: 22,/. 13CD. 

 ExsicCATi : Ellis & Ev. N. Am. Vnj\gi3239; Ellis & Ev. Fungi Columb. 863 ; Seym. & Earle, 

 Econ. Fungi C9, CIO, C 11. 



8. Doassansia intermedia Setch. Bot. Gaz. 19 : 185. 1894. 



Doassansia affinis Ellis & Dearness, Bull. Torrey Club 22 : 364. 1895. (Type from Canada, on 

 Sagittaria variabilis.) 



Sori in leaves, forming light-yellow to brownish subcircular spots, 5-12 mm. in diam- 

 eter, with spore-balls showing as minute hypophyllous pustules ; spore-balls situated in the 

 spongy parenchyma, consisting of a cortex surrounding several layers of spores and a central 

 mass of parenchymatous cells, ellipsoidal to spherical, 200-300 //in length; cortical cells 

 with dark-brown moderately thick walls, chiefly subspherical, cubical, or polyhedral, 

 occasionally more elongate, of medium size, 9-14 /i in length; parenchymatous cells thin- 

 walled, empty, about the size of the spores or slightly larger ; spores adhering rather 

 firmly, ellipsoidal to chiefly spherical, chiefly 8-11 y, in length. 



On Alismaceae : 



Sagittaria latifolia {S. variabilis'), Iowa, Minnesota, New Hampshire, Wisconsin ; Canada. 

 Type locality: Shelburne, New Hampshire, on Sagittaria variabilis (S. latifolia). 



