(454) 



For the aecia: Amelanchier canadensis (L.) Medic, A. erecta 

 Blanch., A. intermedia Spach., A. oblongifolia (Torr. & Gray) 

 Roem., A. vulgaris Moench (cult.), Cydonia vulgaris (L.) 

 Pers. 

 For the telia: Juniperus virginiana L. 

 Type locality: Connecticut, on Juniperus virginiana. 

 Distribution: Massachusetts west to Wisconsin and Iowa, 

 south to Florida and Mississippi. 



Illustration: Bot. Gaz. 49: pi. 22, f. 10. 



Exsiccati: Rab.-Wint. Fungi Eur. 2925; Ellis, N. Am. Fungi 

 1083b, 1086c; Seym. & Earle, Econ. Fungi 239, 240; Ellis & Ev. 

 Fungi Columb. 1623; Ellis & Ev. N. Am. Fungi 314.5; Rav. Fungi 

 Am. 791; Kellerm. Ohio Fungi 185; Rav. Fungi Carol. 5: 87. 



21. Gymnosporangium exterum Arth. & Kern; Arth. Mycologia 

 1: 254. 1909 



Aecia hypophyllous, very sparsely disposed in large groups 

 4-10 mm. across, on discolored spots, 0.1-0.3 mm. in diameter by 

 0.5-0.8 mm. high; peridium soon becoming rather finely lacerate 

 almost to base, spreading but not revolute; peridial cells usually 

 seen only in face view, lanceolate, 10-18X58-100^, inner wall 

 rugose with narrow ridges, side walls 3—5^ thick, sculptured over 

 whole surface like inner wall; aeciospores broadly ellipsoid or glo- 

 boid, 17-21X21-26^, wall very pale cinnamon-brown, 2-2. 5/i 

 thick, very finely verrucose. 



Teha caulicolous, appearing on fusiform dwellings 2-6 cm. long 

 by 0.5-1.5 cm. or more in diameter, causing a considerable roughen- 

 ing and exfoliation of the bark, flattened and applanate, irregular 

 and indefinite in outline, usually anastomosing over practically 

 the whole surface of a swelling, light chocolate-brown; teliospores 

 2-celled, 18-23 X 3 2-42/*, very slightly or not at all constricted at 

 the septum, wall light cinnamon-brown, rather thin, 1-1.5M, 

 usually slightly thicker at apex; pores one in a cell, apical. 



Host plants: 



For the aecia: Porteranthus stipulatus (Muhl.) Britton [Gillenia 



stipulacea Nutt., Spiraea stipulata Muhl). 

 For the telia: Juniperus virginiana L. 



Type locality: Mammoth Cave, Kentucky, on Juniperus 



Distribution: Small area from Central Kentucky to south- 

 Exsiccati: Rab.-Wint. Fungi Eur. 3323. 



