Kern: Studies in the genus Gymnosporangium 507 





Gymnosporangium Davisii sp. nov.* 



Telia chiefly epiphyllous, oval or oblong, 0.7-1 mm. broad, 

 1-2 mm. long, hemispherical, 0.5-1 mm. high, chocolate-brown, 

 surrounded by the ruptured epidermis ; teliospores 2-celled, broadly 

 ellipsoid, 18-28 ft X 40-55 !*, usually narrowed at the base, apex 

 often attenuated, usually furnished with hyaline papillae 4-7 /x 

 thick at the apex and often near the septum in each cell, slightly 

 or . not constricted at the septum; wall cinnamon-brown, 1-1.5 ft 

 rack ; pedicel hyaline, very long, 3-5 ft in diameter ; germ pores 

 one or two, apical or near the septum. 



On Junipenis sibirica Burgsd. {Juniperus nana Willd., Juni- 

 Pmu communis alpina Gaud.) Wind Lake, Racine Co., Wis- 

 consin, May 7, 1905 (type), May 22, .1904,/./ Davis; Isle au 

 Haut, Maine, September, 1903,/. C. Arthur. 



there have been made in this country several collections of 

 t is small, inconspicuous form. It is very characteristic and unlike 

 any other so far reported from this country. It occurs chiefly on 

 eaves, although it may be found sometimes on the smaller 

 s e ms at the bases of the leaves. The finest specimens are those 

 collected by Dr. J. J. Davis, of Racine, Wis., in the edge of a 

 ^marack swamp near Wind Lake, Racine County, Wis. Un- 

 mistakable traces of the same form were found by Dr. J. C. 

 ' rt hur of Purdue University at Isle au Haut, Maine, but owing 

 e Iat eness of the season, it being September when his search 

 made, no spore-masses remained on the leaves. The spores 

 readily distinguishable from all other American forms, now 

 Wn > by the presence of hyaline papillae over the germ pores. 

 ls respect they are very much like the form said to be cultur- 

 * y connected in Europe with Roestelia cormita (Pers.) Fries, 

 owever, the American form both at Wind Lake and at Isle au 

 aut is reported by Drs. Davis and Arthur to be intimately 



ie mis h " S plerum< i ue epiphyllis, ovatis v. oblongis, 0.7-1 mm. latis, 1-2 mm. longis, 

 u flis€ P aericls ' °-5-i mm. altis, fusco-brunneis, epidermide rupta cinctis ; teliosporis 

 ««en at ' S ' latC e,li P soide » s > 18-28 n X 40-55 ft, basi plerumque angustatis, apice saepe 

 fcedit" ' S ' 3P1Ce Ct SEepe J Uxta se P tum in q ua q ue cellula papillis hyalinis 4-7 fi crassis 



crasso 



v -bi n 



is instructis. 



Co u*. ° ll,s ram "Hsque Juniperi sibiricae {Juniper i nanae), Wind Lake, Racine 

 '' >1Sc °nsin,Maio 7 , 1905,/./ Davis. 



