34 Bulletin 313 



asci 4 to 6 or sometimes 9, broadly-ovate, ovate-oblong or sub- 

 globose and without stalk, 5-60 x 30-40 /*; spores 4-7, 18-25 x 

 10-12 fi. 



123. Perithecium, 1/6. 



DiPLOCARPON Ros^ Wolf. (=: Acthionema ros(2^' page 84). 



DiMEROSPORiuM coLLiNSii (Schw.) Thiim. — On green parts of 



Amelanchier canadensis and A. alnifolia. Causes witches' brooms 



and forms a dense mass of brownish, black, septate mycelium on 



the under surface of the leaves, frequently concealing all but the 



midrib and most prominent veins. Conidiospores brown, more or 



less elliptical, 9-13 x 5-7 [x. Perithecia in masses on under surface 



of leaf, occasionally scattered on upper surface, black, globose, or 



polyhedral, with beak which falls away leaving circular ostiola, 150- 



190 ix] asci cylindric-clavate, 8-spored, 45-60 x 10 /x; ascospores 



h3'-aline to pale yellow, ovoid, unequally septate, the septum near 



the base of the spores, 12-15 x 3-5 /z. 



124. Infected leaf of Amelanchier canadensis (under surface). 126. Coni- 

 diospores, 1/6, 1/12. 126. Conidiospores, 1/12. 127. Perithecia, 2/3. 12b. 

 Ascus, 1/12. 129. Ascospores, 1/12. 



Nectria cinnabarina (Tode) Fr. (= Tuberciilaria vulgaris 

 Tode, page 144). — On woody parts of currants, mulberry, Norway 

 maple and many other plants. Primarily a saprophyte but some- 

 times parasitic, causing cankers on woody parts and deatli. When 

 parasitic the cankers always originate with a wound. Stroma 

 breaks through the bark, the tubercularia stage pinkish, becoming 

 yellowish-red and a dark red with age, 1-2 mm. high and broad; 

 conidiophores in tubercular masses, each 50-100 /a long; conidia or 

 short, lateral branches, elliptic, hyaUne, 4-6 x 2 /x. Perithecia 

 massed and frequently concealing the stroma, each perithecium 

 nearly globose with prominent ostiolum, becoming slightly col- 

 lapsed, cinnabar red, becoming darker with age, sometimes black, 

 374-400 fi; asci clavate, 50-90 x 7-12 /a, and 8-spored; spores mostly 

 2-septate, elliptical, elongate, 3 or 4 times as long as broad, obtuse 

 ends, 1-septate, hyaline, usually slightly curved, 12-20 x 4-6 ju. Para- 

 physes delicate. 



130. Conidia (Tubercularia stage), 1/12. 131. Cross-section through 

 stroma and perithecia. 132. Ascus, 1/12. 133. Ascospores, 1/12. 



*Syn. Marssonina rosce (Lib.) Trail — Ann. Mycol. v. 10, p. 146 (1912). 

 *Ref erred to genus Apiosporina by v. Hoehnel (Fragm. zur Mykol., No. 

 506). 



